Department of Chemistry

Umeå University

2012

Removal processes in sewage treatment plants -

Sludge quality and treatment efficiency of

structurally diverse organic compounds

Ulrika Olofsson

Copyright © 2012 Ulrika Olofsson

ISBN: 978-91-7459-356-3

Front cover: Richard Lindberg

Printed by: VMC, KBC

Umeå, Sweden 2012

Till Tove, Hanna, Wilma och Algot

Quidquid discis, tibi discis

“Vad än du lär dig, lär dig det för din egen skull”

Carpe diem

”Fånga dagen”

i

This thesis is based on the following papers, which are referred to

in the text by their respective Roman numerals (Papers I-V).

I. Richard H. Lindberg, Ulrika Olofsson, Per Rendahl, Magnus I. Johansson, Mats Tysklind and Barbro A. V. Andersson. Behavior of fluoroquinolones and trimethoprim during mechanical, chemical, and active sludge treatment of sewage water and digestion of sludge.

Environmental Science and Technology (2006) 40, 1042-1048.

II. Ulrika Olofsson, Staffan Lundstedt and Peter Haglund. Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant. Water Science and Technology (2010) 62, 2880–2888.

III. Ulrika Olofsson, Eva Brorström-Lundén, Henrik Kylin, Peter Haglund. Comprehensive mass flow analysis of Swedish sludge contaminants. Submitted to Chemosphere.

IV. Ulrika Olofsson, Anders Bignert and Peter Haglund. Time-trends of organic contaminants in sewage sludge. Submitted to Water Research.

V. Ulrika Olofsson and Peter Haglund. Use of non-targeted environmetrics and comprehensive two-dimensional gas chromatography to assess sewage treatment plant removal efficiencies of structurally diverse organic contaminants. Manuscript.

Published papers are reproduced with kind permission from the American

Chemical Society (Paper I) and IWA Publishing (Paper II).

Contribution of the author of this thesis to the papers

Ulrika Olofsson was responsible for the following activities: planning of study

with co-author(s) (Papers I, II and V); sampling (Papers I, II and V) or sample

handling (Papers III and IV); laboratory work and instrumental analysis

(Papers I-V); evaluation and interpretation of the data (Papers II-V); and

writing the papers (Papers II-V). Ulrika Olofsson contributed to evaluation and

interpretation of the data, and writing the Paper I.

ii

BOD Biochemical oxygen demand

CMRs Carcinogenic, mutagenic and reprotoxic chemicals

DBT Dibutyltin

DEHP Di-(2-ethylhexyl) phthalate

DINP Di-iso-nonyl phthalate

d.w. Dry weight

EC European Community

EDCs Endocrine-disrupting chemicals

EHDPP 2-Ethylhexyldiphenyl phosphate

EPA Environmental Protection Agency

EU European Union

FQ Fluoroquinolone

GAC Granular activated carbon

GC Gas chromatography

GCxGC Two-dimensional gas chromatography

HRMS High resolution mass spectrometry

IS Internal standard

Kow Octanol-water partition coefficient

LC Liquid chromatography

LOQ Limit-of-quantification

LRMS Low resolution mass spectrometry

MBT Monobutyltin

MCCP Medium chain chlorinated paraffins

MF Mass flow

MRLs Maximum Residue Limits

MS Mass spectrometry

MS/MS Tandem mass spectrometry

NF Nanofiltration

NSAIDs Non-steroid anti-inflammatory drugs

OC Organic compound

OCDD Octachlorinated dibenzo-p-dioxin

OP Organophosphorus compound

i.e. organophosphorus flame retardant and plasticizer

iii

OTC Organotin compound

PAC Powder activated carbon

PAH Polycyclic aromatic hydrocarbon

PBDE Polybrominated diphenyl ether

PCA Principal Component Analysis

PCAs Polychlorinated alkanes

PCB Polychlorinated biphenyl

PCBz Polychlorobenzenes

PCDD/Fs Polychlorinated dibenzo-p-dioxins and furans

PFC Perfluorochemical

PFOS Perfluorooctane sulfonate

POP Persistent organic pollutant

PPCPs Pharmaceuticals and personal care products

PVC Polyvinyl chloride

RE Removal efficiency

REACH Registration, Evaluation, Authorization of Chemicals

RO Reverse osmosis

RoHS Restriction of Hazardous Substances

RS Recovery standard

SA Sludge adsorption

SPE Solid phase extraction

STP Sewage treatment plant

TBEP Tris(2-butoxyethyl) phosphate

TBP Tributyl phosphate

TCEP Tris(2-chloroethyl) phosphate

TCPP Tris(2-chloroisopropyl) phosphate

TDCPP Tris(1,3-dichloro-2-propyl) phosphate

TEQ Toxic equivalent

TOFMS Time-of-flight mass spectrometry

TPP Triphenyl phosphate

WFD Water Framework Directive

WHO World Health Organization

iv

Definitions

Aerobic stabilization and anaerobic digestion

Degradation of biodegradable materials by microorganisms occurs in

the presence or absence of oxygen, respectively, to reduce the waste

volume. Digestion also gives the opportunity to utilize the produced

energy, biogas.

Biochemical oxygen demand (BOD)

A measure of how much biodegradable material there is in the water,

i.e. the amount of dissolved oxygen needed by aerobic biological

organisms to break down organic matter present in the water in a

specific time-frame. BOD is often used as a measure of the STP process

effectiveness.

Mesophilic and thermophilic digestion

These digestions are operated at ca. 37°C or 55°C, respectively, viz. the

temperature at which microorganisms have the best growth to

generate high biogas production (in their respective area, 20-45°C and

<45°C).

Personal equivalent (pe)

A measurement of the amount of oxygen needed to break down the

organic matter that one person produces in one day. The amount is

measured as the oxygen that microorganisms consume over seven days

to break down the organic material in sewage water (BOD7). 1 pe is

equal to 70g BOD7/day.

Sanitation

Treatment of organic waste that significantly reduces the levels of

pathogens (disease-causing microorganisms) to the extent that there is

no risk to humans, animals and plants in the use of end product.

Storm water

Additional water, as roof water, drainage water and leaking rain water

and groundwater, added to the sewer system.

Substitution prefix

Mono (1) one Hexa (6) six Di (2) two Hepta (7) seven Tri (3) three Octa (8) eight Tetra (4) four Nona (9) nine Penta (5) five Deca (10) ten

LIST OF PAPERS .............................................................................................................................. i

ABBREVIATIONS AND DEFINITIONS ................................................................................... ii

1. INTRODUCTION ......................................................................................................................... 1 Main objectives and aim ........................................................................................................................ 10

2. TARGET COMPOUNDS ......................................................................................................... 13 Selection of compounds......................................................................................................................... 13 Sources and use patterns ...................................................................................................................... 17 Physicochemical characteristics of the contaminants ............................................................ 17

3. THE SEWAGE TREATMENT PLANTS ............................................................................ 19

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS ................................................ 23 Sampling ....................................................................................................................................................... 23 Chemical analysis ..................................................................................................................................... 24 Data evaluation .......................................................................................................................................... 28

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY ............................................. 33 Behaviour and fate of sewage contaminants .............................................................................. 34 Swedish sludge quality .......................................................................................................................... 42

6. TIME-TREND ANALYSIS ..................................................................................................... 51 Mass flows and time-trends ................................................................................................................ 52 Action limits ................................................................................................................................................ 58

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS ..... 61 Principal Component Analysis ........................................................................................................... 62 Assessment of the STP’s removal efficiency ................................................................................ 64 Tentative identification of poorly removed contaminants .................................................. 68

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES ...................................... 73 Conclusions.................................................................................................................................................. 73 Future aspects ............................................................................................................................................ 75

ACKNOWLEDGEMENTS ........................................................................................................... 81

REFERENCES ................................................................................................................................ 83

APPENDIX 1................................................................................................................................... A1

1

Large and ever-increasing numbers of chemicals, including large quantities of a

broad spectrum of organic compounds (OCs) are used in modern society. More

than 30 000 of the total number of more than 100 000 chemical substances

registered in the European Union (EU) are estimated to be used daily in Europe

(EC, 1990; Schwarzenbach et al., 2006). Many of these substances will be

discharged into the waste-streams handled by municipal sewage treatment

plants (STPs). The sewage that reaches the STPs originates from several

sources e.g. industrial sites, hospitals and households. The primary purpose of

sewage treatment is to reduce nutrient loads and biochemical oxygen demand

(BOD). However, another important purpose is to act as a partial barrier,

reducing the amounts of carcinogenic, mutagenic and reprotoxic chemicals

(CMRs), persistent organic pollutants (POPs), pesticides, toxic metals and other

potentially harmful anthropogenic substances to levels (in both effluent and

sludge) that will not cause adverse environmental effects. After sewage

treatment the clarified water (effluent) is released into recipient water and the

final solid product is usually sludge that has been anaerobically digested or

aerobically stabilized, and then dewatered. Sewage sludge contains nutrients

and organic matter that can be used in agriculture for soil improvement,

provided that its contents of hazardous substances are sufficiently low.

The contaminant load in sewage streams handled by STPs is highly dependent

on the amount of chemicals used, and patterns of their use, in the communities

served by the STPs. Leakages from consumer products (rates of which depend

on the intrinsic properties of both the compounds themselves and the materials

used) also contribute to the load. Notably, the pharmaceuticals and personal

care products (PPCPs) used directly influence the load, while plastic additives

incorporated in many consumer products are indirect sources. Additional

important sources influencing STPs’ contaminant loads are the large-scale use

of industrial chemicals and stormwater-borne pollution originating from traffic,

other combustion sources and long-range air transport. A schematic diagram of

1. INTRODUCTION

2

the mass flows of chemical substances into the environment via STPs is

presented in Figure 1. The fate of chemical substances after reaching the STPs

during sewage treatment depends on the treatment process and the nature of

the compounds, both of which strongly affect the chemicals’ rates of

evaporation, biodegradation, sorption to sludge and discharge to recipient

water (Zitomer and Speece, 1993).

Figure 1. Schematic diagram of the mass flows of chemical substances derived from both internal and external milieus, via sewage systems to a sewage treatment plant (STP), then through effluent and sludge into the environment.

Numerous studies in recent decades have focused on levels of sewage

contaminants (in effluent and sludge), such as POPs and PPCPs. The results

indicate that many undesirable compounds can be present in STPs’ effluent

and/or sludge at potentially harmful concentrations. STPs can thus be

considered as secondary sources of anthropogenic substances released into the

environment (Harrison et al., 2006; Kinney et al., 2006; Song et al., 2006; Xia et

al., 2005; Zuccato et al., 2010). Once these substances have reached

environmental compartments such as surface water and soil they may pose

threats to aquatic and terrestrial organisms.

Industry HouseholdsHospitals

Sewage

STP

Effluent Sludge

Environment

Offices Public buildings

Traffic Long-range air transport

1. INTRODUCTION

3

Overview of sewage contaminant levels

Traditional OCs are predominantly lipophilic and thus have a high tendency to

sorb to and accumulate in sludge, to ng-mg kg-1 dry weight (d.w.) levels (Bossi

et al., 2008; Langdon et al., 2011; Lindberg et al., 2006; Marklund et al., 2005;

Ricklund et al., 2008; Stevens et al., 2003; Voulvoulis et al., 2004; Ying and

Kookana, 2007). However, the patterns are complex, and levels of several

important classes of potentially harmful compounds have declined recently.

Notably, levels of “traditional” POPs, such as polychlorinated biphenyls (PCBs)

and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), in sewage sludge

have substantially fallen in recent decades (Clarke et al., 2008; 2010).

A comprehensive review of reported concentrations of emerging OCs in sewage

sludge (Clarke and Smith, 2011) in recent decades (1984-2009) concluded that

levels of polychlorinated alkanes (PCAs, industrial chemicals) are higher (480

mg kg-1 d.w. on average) than those of compounds originating from domestic

sources. For instance, average levels of di-(2-ethylhexyl) phthalate (DEHP, a

phthalate that is widely used as a plasticizer in polyvinyl chloride, PVC) and

triclosan (an antibacterial agent used in personal care products) were

reportedly 58 and 4.4 mg kg-1 d.w., respectively. Unsurprisingly, reported levels

of less commonly used industrial and domestic chemicals were much lower, e.g.

organotin compounds (OTCs), polybrominated diphenyl ethers (PBDEs) and

perfluorochemicals (PFCs), for which average reported levels were 0.93, 1.4

and 0.14 mg kg-1 d.w., respectively. They also concluded that concentrations of

PCAs are three orders of magnitude higher than those of PCBs.

Several classes of pharmaceuticals have raised concerns for various reasons.

For instance, the intensive use of antibiotics throughout the world may have

profound effects on microbiological communities in the environment and

enhance risks of antibiotic resistant strains of bacteria developing (Giger et al.,

2003; Holzel et al., 2010). Many of the antibiotics (and other pharmaceuticals)

administered in human medicine are excreted unchanged, mainly in urine and

faeces, and disposal of unused medicine may also be an important source of

these substances. The main route for transportation of these substances to the

environment is via STPs (Choi et al., 2008; Zuccato et al., 2010), thus there is

obvious interest in their fates in STPs, and concentrations of antibiotics have

been determined in sewage water, hospital wastewater, ground and river

water, sludge, soil and manure. Reported concentrations of antibiotics range

from sub or low ng L-1 levels in groundwater and rivers to high g L-1 in

1. INTRODUCTION

4

hospital effluent water. Concentrations in STP effluents range between these

extremes, with reported sludge levels in the mg kg-1 d.w. range (Giger et al.,

2003; Golet et al., 2003; Lindberg et al., 2004; Spongberg and Witter, 2008;

Zorita et al., 2009).

Fate and behaviour of sewage contaminants

The fate and behaviour, in terms of removal efficiency and mass balance, of

emerging and priority compounds, e.g. POPs and PPCPs, have also been

extensively studied during the last decade. Dargnat et al. (2009) and Peng et al.

(2009) found that about 78% of DEHP and 95% of PBDEs were removed from

sewage water handled by a French STP and STPs in the Pearl River delta, South

China, respectively. The high treatment efficiencies for these non-polar

compounds were attributed to their strong sorption to sludge. In contrast,

Marklund et al. (2005) concluded that the overall treatment efficiencies of

organophosphorus flame retardants and plasticizers (OPs) were inadequate at

Swedish STPs, although the treatment process removed alkyl-OPs better than

chlorinated OPs, which mainly tended to pass through the STP unaffected.

These findings are in good agreement with a study by Meyer and Bester (2004).

Most of the semi-polar and polar PPCPs have also low removal rates (Jelic et al.,

2011; Zorita et al., 2009), although the fluoroquinolones (FQs, antibiotics) and

triclosan partly partition to sludge (Bester, 2003; Lindberg et al., 2006; Nakada

et al., 2010). Semi-polar and polar sewage contaminants will thus reach the

STPs’ recipient water at almost the same levels that they entered the STPs.

These findings show that current sewage treatment techniques have limitations

for removing of water-soluble compounds.

Non-targeted screening of sewage contaminants

Most previous studies of effluent concentrations, mass balances and removal

efficiency of sewage contaminants have focused on a specific compound or

group of compounds. This can provide valuable information, but there is an

obvious risk that important contaminants may be missed. Therefore, there is a

need to develop and apply non-discriminating methods capable for

simultaneously determining hundreds, or ideally thousands, of chemicals in

STP influents and effluents. Towards this end, Semard et al. (2008) investigated

the potential use of comprehensive two-dimensional gas chromatography time-

of-flight mass spectrometry (GCxGC-TOFMS) for broadly screening hazardous

compounds in urban sewage water. They identified more than 1 000 chemical

1. INTRODUCTION

5

substances, most of which were removed or decreased during the sewage

treatment process. However, they did not evaluate the sewage contaminants

that were poorly separated, which may be important for improving the

performance of the STPs. More recently, a GCxGC procedure for automatically

searching and evaluating compounds in sewage effluent was developed by

Gomez et al. (2011). The richness of the two-dimensional “fingerprints”

acquired by their GCxGC method provides abundant information about the

contaminants present in the effluent. Such information can be highly valuable

for monitoring changes in sewage water quality, e.g. comparison of

“fingerprints” over time can provide valuable information about temporal

variations in levels of contaminants in STP effluents. However, the full potential

of GCxGC separation techniques has not yet been exploited in sewage

contaminant studies, and the exceptional peak capacity it offers (i.e. its ability

to separate many thousands of chemicals) needs to be combined with an

equally efficient study design and data evaluation protocol.

Environmental objectives for Swedish sewage sludge

In Sweden, approximately 1 000 000 tonnes, or 240 000 tonnes d.w. of sludge is

produced from STPs per year (Swedish EPA, 2007), with phosphorus and

nitrogen contents of ca. 3% (7 200 tonnes) and 3.5% (8 400 tonnes),

respectively. Thus, optimising use of these nutrients in the sludge is highly

important for maintaining phosphorus resources, which are globally depleting

(Steen, 1998). However, both within Europe and elsewhere there are diverse

opinions regarding the suitability of applying sewage sludge to land. For

instance, the Swedish government encourages this practice, while it is

restricted in Switzerland and most of the sludge is incinerated in The

Netherlands. Within the EU and the USA approximately 37% and 60% of ca. 9.9

and 5.6 million tonnes d.w. annually produced is used in agriculture,

respectively (NRC, 2002), and in Sweden ca. 15% is applied to land. Thus, the

Swedish use of sludge in agriculture is currently rather low.

Therefore, according to a Swedish government decision, by 2015 at least 60%

of the phosphorus originating from sewage should be returned to productive

soil, half to arable land (Swedish EPA, 2002). To achieve this nutrient recycling

goal, contents of hazardous substances in sewage sludge, and the risk of

spreading infections if the sludge is applied to sensitive land, must be reduced.

Further, the deposition of organic material, such as sewage sludge, on waste

dumps has been banned in Sweden since 2005 (Ministry of the Environment,

1. INTRODUCTION

6

2001). This has resulted in considerable interest in alternative applications for

such waste, e.g. as fertilizer for forested or other non-arable land (roadsides,

abandoned dump sites or open-cast mines, etc.), or incineration for energy

production. However, these options may hamper attempts to promote

sustainability and fulfil the goal of the Swedish National Environmental

Protection Agency (Swedish EPA) to increase the use of sludge in agriculture.

The greatest challenge may be to reduce the contents of hazardous substances

(such as POPs, toxic metals, pesticides, hormone-disrupting chemicals (EDCs),

carcinogens and pathogens) in sludge and sludge-amended soil sufficiently to

fulfil legal requirements and, equally importantly, to convince consumers and

consumer organisations that products grown on such amended soil are safe.

Guideline values of sludge contaminants and legislation

There are no legal limits, today, for OCs in sewage sludge intended for

agricultural uses. However, European Maximum Residue Limits (MRLs) (EU,

1986) have been established for metals, and implemented in various countries,

e.g. Greece, Ireland, Italy, Luxembourg, Portugal, and Spain. In addition, stricter

limit concentrations have been set in some other countries, e.g. Belgium,

Denmark, Finland, The Netherlands and Sweden (Ministry of the Environment,

1998). Sludge from Swedish municipal STPs generally complies with these

limits (Haglund and Olofsson, 2007; 2008; 2009; 2010; 2011) and suggested

limits in the European Community (EC) sludge draft directive “Working

document on sludge”, as outlined below (CEC, 2000). In the USA, the limits for

metals in biosolids (treated sewage sludge) applied to land are slightly higher

(U.S. EPA, 1993). The limit values for metals in sludge (for land applications) in

the EU, Sweden and the USA are summarized in Table 1. The more than 20-year

old EC sludge directive is currently under review and revision (CEC, 2011) and

in Sweden the EPA has submitted a proposal to amend the limits for metals.

1. INTRODUCTION

7

Table 1. Limit concentrations, mg kg-1

d.w., of metals in sewage sludge for use on land.

Metals EU EUa

Sweden Swedenb

USA

Cd 20 - 40 10 2 1.3 85

Cr - 1 000 100 100 -

Cu 1 000 - 1 700 1 000 600 600 4 300

Hg 16 - 25 10 2.5 1.0 57

Ni 300 - 400 300 50 50 -

Pb 750 - 1 200 750 100 100 840

Zn 2 500 - 4 000 2 500 800 800 7 500

Ag - - - 8 -

As - - - - 75

Ni - - - - 420

Se - - - - 100 aProposed limits in the EU (CEC, 2000).

bProposed limits in Sweden

(Swedish EPA, 2010).

Despite the lack of legal limits for OCs in sludge, recommended MRLs have been

set for three groups of organic “indicator” pollutants: six polycyclic aromatic

hydrocarbons (PAHs; sum, 3 mg kg-1 d.w.), indicator-PCBs (sum, 0.4 mg kg-1

d.w.) and 4-nonylphenol (50 mg kg-1 d.w.), through a voluntary agreement

between the Swedish EPA, the Federation of Swedish Farmers and the Swedish

Water & Wastewater Association (Swedish EPA et al., 1995). These pollutants

are included in the STPs’ monitoring programs and are reported in their annual

environmental reports. The EC sludge directive (CEC, 2000) also suggests limit

values for concentrations of total halogenated OCs (AOX, 500 mg kg-1 d.w.),

linear alkylbenzene sulphonates (LAS, 2 600 mg kg-1 d.w.), DEHP (100 mg kg-1

d.w.), 4-nonylphenol and nonylphenol-ethoxylates (NPEs, 50 mg kg-1 d.w.), nine

PAHs (sum, 6 mg kg-1 d.w.), indicator-PCBs (sum, 0.8 mg kg-1 d.w.) and

PCDD/Fs (100 ng TEQ kg-1 d.w.).

In addition, a number of OCs and metals are classified as priority substances in

the EU Water Framework Directive (WFD) (EU, 2000). Currently 33 priority

substances (of which 13 are classified as hazardous) are regulated by this legal

framework, and the list is under constant review. The increasing contamination

of natural water systems with anthropogenic compounds is a major problem

throughout the world, due to their largely unknown long-term effects on

aquatic life and human health, and the purpose of the WFD is to protect the

water quality in European countries. The Stockholm Convention on POPs

1. INTRODUCTION

8

(UNEP, 2001) is another legally binding agreement, which was adopted on May

22nd 2001, entered into force on May 17th 2004, and has been ratified by

numerous countries, including Sweden. POPs are of particular concern since

they are resistant to chemical and biological degradation and can remain intact

in the environment for long times. POPs also have a strong tendency to

bioaccumulate in fatty tissue of living organisms, and even at extremely low

concentrations they pose health risks to humans and wildlife. Currently (2011),

21 priority pollutants are listed under this global convention, but proposals

have been made to include a large number of other compounds in the protocol.

Today, most chemical restrictions apply across Europe under the REACH

(Registration, Evaluation, Authorization of Chemicals) Regulation (EU, 2006),

which replaced much previous chemical legislation. REACH entered into force

across the whole EU on June 1st 2007 and will be applied step by step in the

Member States. This Regulation stipulates that Member States, e.g. Sweden,

must implement its clauses either directly or through appropriate national

legislation. The basic framework consists of the REACH and CLP (Classification,

Labeling and Packaging; EU, 2008) regulations, which require knowledge and

labeling of all chemical substances manufactured in, or imported into, the EU.

REACH also covers mechanisms for risk assessments of hazardous compounds,

license requirements and use limitations. Some chemical substances are also

regulated by other product-specific directives, e.g. the use of cadmium,

mercury, lead, hexavalent chromium and the flame retardants polybrominated

biphenyl (PBB) and PBDEs in new electrical and electronic equipment in the EU

market has been prohibited since July 1st 2006 by the RoHS (Restriction of

Hazardous Substances) directive (EU, 2003).

These types of national and international environmental legislation and

regulations are intended to reduce levels of hazardous substances in the

environment in order to safeguard the sustainability of ecosystems and human

health. They have proven to be powerful tools for minimizing the release of

such compounds into the environment. National bans of PCBs in the 1970s and

the international regulation of POPs, including PCDD/Fs, in the Stockholm

Convention (UNEP, 2001), have resulted in substantial reductions of these

compounds in the environment. As mentioned earlier, there are also

indications that levels of PCBs and PCDD/Fs in sewage sludge have decreased

in recent decades (Clarke et al., 2008; 2010). However, these kinds of

regulation and legislation only cover parts of the enormous flows of chemicals

in the technosphere, thus intense efforts are being made globally to identify

1. INTRODUCTION

9

new or “emerging” pollutants that may have been overlooked or have been

recently introduced to the market. Furthermore, the potentially adverse

interactive or “cocktail effects” that combinations of a large number of

chemicals may have on the environment, and human or animal health, are

poorly understood and generally neglected.

Sewage sludge as a matrix for environmental monitoring

Even if sewage sludges are not recycled it is an important environmental

matrix for monitoring, to obtain socio-economic “fingerprints” of the OCs used

by the communities that generate them and for assessing the diversity and

abundance of the myriads of chemicals used today that end up in waste and

final recipient waters (both nationally and globally).

Therefore, in 2004, the Swedish EPA started to include sewage sludge in its

national environmental monitoring program to obtain an integrated

understanding of the types and amounts of hazardous substances circulating in

the technosphere that reach STPs, associate with sewage sludge, and may

subsequently leach into the environment. Since then, annual measurements of

prioritized sludge contaminants from selected STPs have been performed (in

one of the studies underlying this thesis, see below), allowing time-trend

analysis within a reasonable time-span. The sludge monitoring data can be

used to follow-up effects of regulatory actions, to screen new and emerging

compounds and to monitor the quality of the sewage sludge. In parallel to the

annual sampling for monitoring, subsamples are also taken for archiving in an

environmental specimen bank that will be valuable in the future for tracking

changes (trends) in sludge contaminant concentrations as consequences of

regulatory actions. Archiving sludge will also allow retrospective monitoring of

chemical substances that are not of concern today. Effects of future

substitutions of compounds by others, hopefully less toxic to humans and the

environment, can also be easily evaluated and validated by retrospective

analyses of archived sludge, which is essential from legislative, environmental

and toxicological perspectives.

1. INTRODUCTION

10

Main objectives and aim

The fate and behaviour of chemical substances during sewage treatment and

their levels in (inter alia) STP influent and effluent water, and sludge, have

received considerable global attention in recent decades. However, greater

knowledge of numerous associated phenomena is still required. The main

objective of the research this thesis is based upon was to improve

understanding of the relationships between the characteristics (structural and

physicochemical) of sewage contaminants and their sewage treatment

efficiency. Further objectives were to examine the relationships between socio-

economic uses of chemicals and sludge quality, and the effects of regulatory

actions on sludge quality. More specific aims were to enhance our knowledge

about:

the quality of the sludge produced by STPs, in terms of the contaminants

that accumulate in it, their mass flows (calculated from their levels in

sludge and annual national use levels), and the relationships between

the chemicals’ fates and physicochemical properties;

time trends in levels of sewage sludge contaminant concentrations (if

any are detectable over a reasonable time-span), and the effectiveness of

attempts to reduce the release of harmful substances into the

environment, e.g. through legislation and regulations;

the total STP removal efficiency of anthropogenic substances (influent

versus effluent levels) and the effectiveness of specific treatment steps;

the power of comprehensive GCxGC-TOFMS for unbiased (non-targeted)

characterization of sewage water (influent and effluent), and its utility

for identifying, quantifying and estimating the removal efficiency of

structurally diverse GCxGC-amenable OCs in sewage, especially those

that are poorly removed.

These results may facilitate identification of the upstream measures required to

reduce the inflow of undesirable substances to the STPs, and possible

improvements of sewage treatment processes to minimize the release of

undesirable compounds into the environment. They could also be useful for

risk assessments of sludge applications on land. Moreover, the data provide

detailed information about the environmental load derived from STPs,

especially Swedish STPs, which may be valuable for revising environmental

1. INTRODUCTION

11

legislation and restrictions, if necessary. Further, the possibility of using sludge

stored in the environmental specimen bank will greatly facilitate future studies

of established, emerging and new contaminants that are expected to

accumulate in sewage sludge. These kinds of studies can be very important for

overviews of current and future chemical flows in the technosphere, and their

possible environmental impact.

The papers appended to this thesis examine the behaviour and fate of

anthropogenic substances in an STP (Papers I and II) and the mass flows of

selected compounds used in the served society that are sorbed to sewage

sludge (Paper III). Paper IV presents time-trend analyses of sludge

contaminants, based on statistical evaluation of seven years of measurements.

Finally, the STP removal efficiency of non-targeted (poorly removed) sewage

contaminants was investigated using GCxGC-TOFMS (Paper V).

12

13

In the studies this thesis is based upon, 285 anthropogenic compounds in total

were investigated. CAS numbers and selected physicochemical properties of the

target compounds are presented in Table S1 of Supplementary data for Paper

III, and their molecular structures are shown in Appendix 1 of the thesis. Main

applications and the quantities used annually in Sweden (based on data from

2004) are summarized in Table 2, and their physicochemical properties in

Table 3. It should be noted that the annual quantities recorded in the Swedish

product register (Swedish Chemicals Agency, 2011) do not include chemicals

manufactured or imported in quantities less than 100 kg per company nor

those present in imported consumer articles. Therefore, the product register

can give misleading indications of amounts that could be potentially released

into the environment.

Selection of compounds

The sludge contaminants were selected by the authors of the appended papers,

in consultation with the Swedish EPA, from Scandinavian priority lists, the EU

WFD (EU, 2000), or the draft EC Directive “Working document on sludge” (CEC,

2000), some of which are classified as POPs (UNEP, 2001) or WFD priority

substances (EU, 2000), see Table S1 (Supplementary data, Paper III). The WFD,

EC sludge directive and Stockholm Convention on POPs are briefly described in

Chapter 1. The focus was on (semi-)lipophilic compounds that may be sorbed

on sludge, ignoring volatile compounds due to their potential to evaporate

during sewage treatment processes. Thus, only non-volatile and semi-volatile

compounds that are unlikely to evaporate much were included. Moreover,

these selected compounds are representative of a large portion of semi-volatile

OCs found in sewage sludge. By studying the levels of these sludge

contaminants we can create general knowledge about the Swedish sludge

quality. An overview of the diversity of the target compounds, in term of size,

polarity and functional groups etc. are given in Figure 2.

2. TARGET COMPOUNDS

14

Table 2. Main applications and quantities of the target compounds used annually (in Sweden)

Compounds na Applications

Quantityb

(103 kg year-1)

As, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Zn 10 Metals, ingredients in cosmetics 21 046

Phthalates 8 Plasticizers, e.g. in polyvinyl chloride (PVC), and additives in personal care products, e.g. in fragrances

73 964

Biocides 11 Killing living organisms 1 637

Polycyclic aromatic hydrocarbons (PAHs)

6 Products of incomplete combustion 1 203c

Adipates 8 Softening agents in plastics 1 073

Pesticides 109 Pest control 828

Polychlorinated alkanes (PCAs) 3 Lubricants and cutting fluids (metal working industry), flame retardants and plasticizers

298

Organophosphorus compounds (OPs)

8 Flame retardants and/or plasticizers in textiles, plastics and building materials

286

Butylhydroxytoluene (BHT) 1 Stabilizer in plastics and rubber, antioxidant (e.g. in processed food)

254

Organotin compounds (OTCs) 6 Anti-foulant and stabilizer in polyvinyl chloride (PVC)

240

Non-steroid anti-inflammatory drugs (NSAIDs)

4 Pharmaceuticals 84d

Siloxanes 7 Sanitary articles, lubricants and hydraulic fluids in textiles and skin care products

31

Perfluorochemicals (PFCs) 13 Water, fat or stain repellents for paper, textiles, carpets, etc.

24e

Terpene (Limonene) 2 Flavour and odour additive (hygiene products and perfumes)

17

Polychlorobenzenes (PCBz) 11 Dyestuffs and solvent for pesticides 8.1f

4-Nonylphenol 1 Detergent, surfactants (metabolite) 7.6

Fluoroquinolones (FQs) 3 Pharmaceuticals (antibiotics) 5.1d

Trimethoprim 1 Pharmaceutical (antibiotic) 1.0d

Polybrominated diphenyl ethers (PBDEs)

8 Flame retardants in electronics, furniture and building materials

3.6g

Triclosan (TCS) 1 Antibacterial agent in personal care products, e.g. in toothpaste and deodorants

3.1

Tetracyclines (TCs) 5 Pharmaceuticals (antibiotics) 1.3d,h

Hormones 4 Pharmaceuticals 0.07d

Chlorophenols (CPs) 19 Wood and textile preservatives Banned (1978)i

Polychlorinated biphenyls (PCBs)

WHO-PCBs

Indicator (I)-PCBs

12

7

Dielectric fluids in transformers and capacitors

Banned (1972)i

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs)

17 Unintentionally formed (by-products) -

an: number of compounds included in the group. Pesticides: insecticides, herbicides and fungicides.

bAnnual quantity used in Sweden in 2004 (Swedish Chemicals Agency, 2011). cQuantity of benzo(a)pyrene. dSwedish MPA (2004). eSwedish Chemicals Agency (2006). fQuantity of 1,2-dichlorobenzene. gQuantity of PBDE 209. hDemeclocycline and chlorotetracycline not included. iIn Sweden.

2. TARGET COMPOUNDS

15

Table 3. Physicochemical properties of the studied compounds (EPI Suite™, 2007).

Class of compound Sub group

Mw

(g mol-1)a log Kowb

Sw (mg L-1)c

H (atm·m3 mol-1)d

Metals As, Cd, Co, Cr, Cu, Hg,

Ni, Pb, V, Zn 51 - 207 −0.6 - 0.7 6·104 - 4·105 2·10-2 - 0.8

Esters Phthalates

Adipates OPs

194 - 447 202 - 427 266 - 431

1.7 - 10 2.4 - 10 1.6 - 4.7

1·10-5 - 8·103

4·10-6 - 690 5 - 6·103

4·10-8 - 4·10-5

2·10-6 - 2·10-4

1·10-11 - 3·10-6 Pesticides Biocides 110 - 362 1 - 4.7 7·10-6 - 3·105 6·10-12 - 5·10-7 Insecticides

Herbicides Fungicides

183 - 505 111 - 412 169 - 403

−0.9 - 7.4 −4.5 - 5.3 0.9 - 5.5

2·10-3 - 1·106

5·10-2 - 1·106

4·10-2 - 9·103

3·10-12 - 4·10-4

4·10-19 - 2·10-4

8·10-14 - 3·10-5

Hydrocarbons PAHs

Terpene (Limonene) 202 - 276 136

4.9 - 6.7 4.8

2·10-4 - 9·10-2

44 1·10-7 - 8·10-6

0.4 Phenols Chlorophenols

Butylhydroxytoluene Triclosan 4-Nonylphenol

129 - 266 220 290 220

2.2 - 4.7 5.0 4.7 5.9

45 - 1·104 10 9.3 2.7

1·10-7 - 4·10-7 4·10-6 5·10-9

6·10-6 Organometals Organotin

compounds 177 - 351 0.6 - 7.4 6·10-7 - 4·103 1·10-9 - 1.5

Pharmaceuticals Fluoroquinolones

Tetracyclines 319 - 361 444 - 483

−0.3 - 0.3e

−4 - −0.7 7·103 - 4·104

160 - 3·105 5·10-20 - 9·10-19

1·10-31 - 5·10-24 NSAIDs

Hormones 206 - 296 272 - 298

3.0 - 4.0 2.8 - 4.1

11 - 260 13 - 560

5·10-12 - 2·10-7

1·10-12 - 6·10-10

Siloxanes Methylsiloxanes 162 - 445 4.8 - 6.5 1·10-4 - 1.4 9·10-2 - 0.8 Fluorinated compounds

Perfluorochemicals 314 - 714 2.2 - 12 6·10-7 - 2 1·10-9 - 2·103

Halogenated compounds

Polychlorobenzenes PBDEs I-PCBs WHO-PCBs

PCDD/Fs

147 - 285 407 - 959 258 - 395 292 - 395 306 - 460

3.3 - 5.9 5.9 - 12 5.7 - 8.3 6.3 - 8.3 6.3 - 9.5

0.3 - 100 3·10-6 - 0.3 4·10-4 - 0.1 4·10-4 - 3·10-2

9·10-6 - 3·10-2

9·10-4 - 3·10-3 1·10-8 - 7·10-6

5·10-5 - 2·10-4

5·10-5 - 1·10-4

1·10-6 - 2·10-5

PCAs Depend on the degree of chlorination

Abbreviations can be found in Table 2. aMw: Molecular weight. blog Kow: octanol-water partition coefficient, estimated values. cSw: Water solubility, estimated values. dH: Henry´s Law Constant, estimated values. eExperimentally determined value (Takacs-Novak et al., 1992). Table from Paper III.

2. TARGET COMPOUNDS

16

Figure 2. A selection of the target compounds. Mw, molecular weight (g mol-1); log Kow,

octanol-water partition coefficient; Sw, water solubility (mg L-1); H, Henrys Law Constant

(atm·m3 mol-1) (EPI Suite™, 2007).

Tris(2-chloroethyl) phosphate (TCEP)Mw: 285.49log Kow: 1.63Sw: 5 597H: 2.6 · 10-8

Tris(2-butoxyethyl) phosphate (TBEP)Mw: 398.48log Kow: 3.00Sw: 604H: 1.2 · 10-11

NHN

N

CH3

O

OH

O

F

NorfloxacinMw: 319.34log Kow: -0.31Sw: 40 231H: 8.7 · 10-19

O

OCH3

CH3

O

O CH3

CH3

Di-(2-ethylhexyl) phthalate (DEHP)Mw: 390.57log Kow: 8.39Sw: 1.3 · 10-3

H: 1.2 · 10-5

OBr

Br

Br

Br

Br

Br

Br

Br

Br

Br

PBDE 209Mw: 959.17log Kow: 12.11Sw: 2.6 · 10-6

H: 1.2 · 10-8

OCDFMw: 443.76log Kow: 8.87Sw: 7.6 · 10-5

H: 4.7 · 10-6

Cl

ClCl

OCl

Cl

ClCl

Cl

Cl

Cl

Cl

O

Cl

Cl

Cl

Cl

O

Cl

OCDDMw: 459.76log Kow: 9.50Sw: 9.3 · 10-6

H: 1.1 · 10-6

O

OH

Cl ClCl

Triclosan (TCS)Mw: 289.55log Kow: 4.66Sw: 9.3H: 5.0 · 10-9

OH

Cl

Cl

Cl Cl

Cl

Pentachlorophenol (PCP)Mw: 266.34log Kow: 4.74Sw: 45H: 1.3 · 10-7

Cl Cl

Cl

Cl

Cl

Cl

Hexachlorobenzene (HCBz)Mw: 284.78log Kow: 5.86Sw: 0.3H: 8.9 · 10-4

CH3Si

OSiO

Si

O

Si

O Si

CH3CH3

O

Si

O

CH3

CH3CH3

CH3

CH3

CH3

CH3CH3CH3

Dodecamethylcyclohexasiloxane (D6)Mw: 444.93log Kow: 6.33Sw: 2.1 · 10-3

H: 0.17

S

O

O

O

K

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

Perfluorooctane sulfonate (PFOS)Mw: 538.22log Kow: 4.13Sw: 7.6 · 10-6

H: n.e.

Br

Br

O

Br

Br

PBDE 47Mw: 485.79log Kow: 6.77Sw: 5.4 · 10-2

H: 3.0 · 10-6

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP)Mw: 430.91log Kow: 3.65Sw: 30H: 2.6 · 10-9

O

O

O

CH3

CH3

O

CH3

CH3

Di-iso-nonyl phthalate (DINP)Mw: 418.62log Kow: 9.37Sw: 1.2 · 10-4

H: 2.1 · 10-5

Cl

Cl

Cl

Cl

Cl

PCB 118Mw: 326.44log Kow: 6.98Sw: 7.3 · 10-3

H: 9.2 · 10-5

Cl

Cl

Cl

Cl

PCB 77Mw: 291.99log Kow: 6.34Sw: 3.2 · 10-2

H: 1.3 · 10-4

CH3

Si CH3

CH3O

SiCH3

CH3

O

Si

CH3CH3

OSi

CH3

CH3

OSi

CH3

CH3 CH3

Dodecamethyltetrasiloxane (MD3M)Mw: 384.85log Kow: 6.52Sw: 1.1 · 10-4

H: 0.79

CH3O

O

PO

OO CH3

O O CH3

Cl

O

PO

OCl

O

Cl

ClO

P

O

O

Cl

Cl

OCl

Cl

Cl

2. TARGET COMPOUNDS

17

Sources and use patterns

The contamination load derived from STPs is highly dependent on the patterns

of use of the numerous chemical substances circulating in the technosphere of

the society served by the STPs. Nonpoint source pollution by diffuse dispersion

of pollutants, such as PAHs, PCBs and PCDD/Fs, from diverse sources, via long-

range air transport, land or streets and then through storm water systems and

sewers, continuously contributes to the chemicals contained in sewage.

However, point source pollution, in which the pollution comes from a specific

site (and is easier to control than nonpoint source pollution), may also be

contribute to the chemical content in sewage.

Intended uses of consumer products such as PPCPs readily (and inevitably)

lead to their release to the sewer system, thus the quantities used and sewage

levels are directly linked. Leakage from consumer goods is another source of

chemical substances to STPs. Notably, flame retardants and plasticizers are

slowly emitted from the large stocks of consumer articles and building

materials in the communities served, which may therefore be significant

sources of such chemicals in the sewer system. Consumer products are likely to

be more important emitters (molecular emissions) of volatile than semi-

volatile (higher molecular weight) compounds. For semi-volatile pollutants,

particulate emissions may be more important. Compounds may also be emitted

from consumer products through leaching during washing or cleaning.

Physicochemical characteristics of the contaminants

The characteristics (physicochemical properties) of the sewage contaminants

are, as mentioned earlier, summarized in Table 3 while more detailed

information is given in Table S1 of the Supplementary data for Paper III. In

addition to their use patterns (as outlined above), the physicochemical

properties of pollutants also strongly affect the likelihood that they will reach

STPs, and their behaviour and fate during the sewage treatment process if they

do.

During sewage treatment the compounds may, for instance, evaporate and/or

be degraded. Polar (highly water soluble) compounds and those with low

sludge affinity (low log Kow values) that are not readily biodegradable are likely

to pass through an STP virtually unaffected by the process. The volatility

(tendency of a substance to evaporate, which is negatively correlated with its

2. TARGET COMPOUNDS

18

molecular weight) of a compound may affect both initial emission rates of

additives from consumer products and evaporative losses in the sewage

treatment process. However, during sewage treatment process only the most

volatile OCs appear to be vented away to any great extent.

The compounds’ tendency to be biodegraded during the process will affect

their fate in STPs and, indirectly, the climate at the STPs’ location is also

influential. For example, the water temperature will be lower in STPs located in

the far north than in southerly STPs, hence the biological activity in them

towards biodegradable compounds and their removal efficiency are also likely

to be lower (IVL, 2006a). The generally lower availability of more lipophilic

molecules for biodegradation is another influential factor. Non-polar

compounds (with high logKow and low water solubility values) are likely to

have high affinity for sludge (and thus strong tendencies to sorb to it), in

addition to low biodegradability. Hence, these compounds are generally found

exclusively in sludge.

However, many chemical substances that reach STPs are semi-polar, semi-

volatile or semi-biodegradable and their behaviour during the treatment

process is intermediate compared to the extremes mentioned above. The

complexity of sewage (e.g. its high, but variable, content of organic matter) also

influences, and reduces the predictability of, compounds’ fates and behaviour in

STPs.

19

The municipal STPs considered in this thesis are spread across Sweden, see

Figure 3. In their selection, particular account was taken of their size, load,

technical parameters, proportions of industrial, household and other waste

handled, and geographic locations. The following plants have been investigated:

Stockholm (STP A); Gothenburg (STP B); Umeå (STP C); Eslöv (STP D); Borås

(STP E); Alingsås (STP F); Borlänge (STP G); Floda (STP H); Bollebygd (STP I);

and Bergkvara (STP J). These plants represent large STPs (A, B) serving large

cities, medium-sized STPs (C-G) processing mixed sewage from residential

areas and large industrial sites and/or hospitals and small STPs (H-J) with

negligible industrial loads.

These STPs use conventional sewage treatment methods that include:

mechanical processes (screening and removal of sand and fat); chemical

treatment (flocculation of phosphorus with an agent such as ferrous sulphate

or ferrous chloride); and biological processes (degradation of organic material

by microorganisms and removal of the remaining phosphorus). Solids are

removed from the water by clarifiers as sludge, which is then anaerobically

digested or aerobically stabilized (i.e. organic material is degraded in the

absence or presence of oxygen, respectively) and finally dewatered. However,

almost every STP is unique in terms of its treatment processes, the size of the

human population it serves and the types of associated activities. Descriptive

data of the studied STPs are given in Table 4.

3. SEWAGE TREATMENT PLANTS

20

Figure 3. Locations of the selected Swedish STPs (A-J). STP ID, see Table 4.

Umeå STP (STP C in Figure 3) was the plant considered in Papers I, II and V,

thus its treatment processes are described in more detail below. It is located in

the northern part of Sweden, where the climate is cold, with a yearly average

temperature of 3.4°C. The STP serves a population of almost 100 000 people

(2010), and receives mixed raw sewage (13 Mm3 year-1), mainly consisting of

domestic water (ca. 20% storm water), but also some sewage from industrial

sites and a large hospital.

The treatment processes include: mechanical, chemical (phosphorus

flocculation using ferrous sulphate, FeSO4) and biological treatment. Primary

and secondary clarifiers (handling waste derived from chemical and biological

treatment, respectively) are used for removing solids from the water, as sludge.

Most of the sludge produced in the secondary clarifier is reused to retain and

recycle the microorganisms in the biological treatment. The duration of the

recycling time of this sludge is about three days, and a minor amount is

returned to the influent. The sludge generated during the primary clarification

(i.e. chemical sludge) is then anaerobically digested (retention time, 18 days)

together with external sludge from the municipality’s other STPs (of the total

FHB

IG

DJ

A

G

C

N

3. SEWAGE TREATMENT PLANTS

21

ca. 2 300 tonnes d.w. year-1 sludge produced, ca. 17% is derived from external

sources). After digestion polymer is added then the sludge is dewatered (by

centrifugation) to a d.w. of 31%. A schematic diagram of the treatment process

can be seen in Figure 4, which also shows residence times throughout the plant.

Figure 4. Schematic diagram (modified from Papers I and II) of the sewage treatment process in Umeå STP, including residence times throughout the plant and the sampling locations used in the studies described in Papers I and II.

10 h

20 min

2.5 h

Sand/fat

removal

Screen Pre

aeration

Primary

clarifier

Activated sludge

treatment

Secondary

clarifier

Thickener

Anaerobic

digester

Sludge

siloDewaterer

Dewatered (digested) sludge

PelletThin layer

drier

Moving belt

drier

Final effluent

Raw sewage water

Sampling location

FeSO4

External sludge

18 days

Polymer

Aerated effluent

Primary effluent

30 min 45 min 1.5 h 1.8 h 3.6 h

Raw sludge

Digested sludge

Sludge, primary clarification

Sludge, secondary clarification18 h

A B C D

E F

G

H

I

J

K

A

B

C

D

E

F

G

H

I

J

K

Table 4. Descriptive data for the selected Swedish sewage treatment plants (STPs, 2010).

Stockholm Gothenburg Umeå Eslöv Borås Alingsås Borlänge Flodaa Bollebygd Bergkvara

STP ID A B C D E F G H I J

No. of personal equivalents (pe)

656 000 640 000 129 000 74 000 73 000 27 000 25 000 6 000 3 700 2 500

Inhabitants served 737 000 649 000 92 000 20 000 82 000 26 000 44 000 10 000 4 100 5 900

Dimensioning of the STP (pe) 900 000 680 000 116 000 330 000 110 000 60 000 60 000 13 000 6 000 6 500

Type of activity connectedb Ind. (mix) Ind. (mix) H Ind. (F) H/Ind. (T, C) Ind. (L) H House House House

Treatment of the sewagec M/C/B/D M/C/B/D M/C/B/D M/B/C/D M/C/B/D M/C/B/D M/C/B/D M/C/B/S M/B/C/S M/B/C/S

Solid tr (days)d 19 15 18 30 25 17 15 -- -- --

Raw sewage water

(Mm3 year-1)

89 119 13 3.7 13 3.2 5.6 1.5 0.24 0.6

Storm water (%) 5 57 20 28 50 24 35 66 21 46

Sewage sludge

(tonnes d.w. year-1)

14 400 13 300 2 300 1 100 2 400 690 1 200 270 78 110

Fraction of total production (%)e

6.0 5.5 1.0 0.46 1.0 0.29 0.5 0.11 0.033 0.046

Sewage sludge d.w. (%) 27 30 31 18 21 23 35 30 2.4 17 aFloda STP (2005). bInd., industry; mix, mixture of industrial sewage; F, food; H, hospital; T, textile; C, chemical; L, laundry; and House, household. cM, mechanical; C, chemical; B, biological treatment (activated sludge); D, digestion (anaerobic); and S, stabilization (aerobic) of the sludge. dSolid retention time in the digester. ePercentage of the total annual production of sewage sludge in Sweden (240 000 tonnes d.w. per year; Swedish EPA, 2007). Table from Paper IV.

23

Sampling

General overview

General overviews of the sampling strategies applied in the studies underlying

this thesis (Papers I-V) are presented below, while additional, more detailed

information is provided in the respective papers. The sampling campaigns were

carried out during periods of normal working and weather conditions. Further,

samples were taken in the middle of the week to minimize effects of the

reductions in many industrial activities that occur during weekends and other

weekend activities that may affect sewage water and sludge contents. All

samples were collected in dark pre-treated bottles (extensively cleaned and

treated at 550°C overnight, unless otherwise stated) and, in order to reduce the

risk of microbial degradation, immediately stored at 4°C (water) or -18°C

(sludge) until chemical analysis.

Annual sampling of sewage sludge

One of the objectives of the studies was to obtain samples from selected STPs

annually to explore temporal trends in pollutant loads (see Chapter 1). Sweden

has a temperate climate with daily average January temperatures varying from

0°C in the south to -15°C in the north, but temperatures are generally more

uniform from late spring to autumn. Therefore, composite dewatered digested

(anaerobic) or stabilized (aerobic) sludge samples (n=3, grab-sampled) from

each selected STP were collected annually in September/October when the

temperature at all sampling locations is similar (average, 10°C) to maximize the

comparability of the samples (Papers III and IV). Further, in spring the

frequency of flooding events is high, and during the summer holiday period

patterns of socio-economic activities change markedly. Thus, autumn appeared

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

24

to be the optimal time for obtaining reliable data (in terms of effects of

household and industrial uses of anthropogenic substances).

Sampling of sewage water, solids and sludge at Umeå STP

For detailed analysis of the waste streams and effects of STP processes on

selected pollutants, both influent and effluent sewage water (Papers I and V)

were gathered at Umeå STP as flow-proportional samples (24-hours) using the

plant’s existing automatic sampler. To obtain sufficient total sample volumes

for the mass balance analysis reported in Paper II, grab samples of the water

and solid (sludge) phases were collected throughout the STP, according to

residence times in the respective processes (Papers I and II). The sampling

locations used in these studies were designated A-K, of which all were used in

the first study (Paper I) while A, D, E and J were used in the second study

(Paper II), and are schematically displayed in Figure 4. These sampling points

were selected to be able to analyse in detail the distribution of the target

compounds within the STP’s process streams, but due to the more extensive

study presented in Paper I selected locations throughout the process were

used.

Chemical analysis

Environmental samples, in general, can be categorized as complex matrices that

require careful preparation, extraction, clean-up and instrumental analysis. The

complexity of sewage water and sewage sludge is largely due to their high

organic matter contents, and thus high levels of non-target compounds, arising

from soil and diverse other sources, both environmental and anthropogenic.

The analysis of trace contaminants in environmental samples is possible today

due to recent enhancements of instrumental techniques allowing their

detection at pg-fg levels. Highly selective analytical procedures are also

required in order to avoid interferences from non-target compounds (biogenic

and anthropogenic) present in the samples in orders of magnitude higher

concentrations. Therefore, rigorous pre-treatment of sampled matrices to

enrich the target compounds is still often required, and was essential for most

of the chemical analysis of sewage matrices considered here, to obtain as pure

chromatograms as possible and thus avoid false positive identifications and

biased quantifications.

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

25

A widely used method for quantifying contaminants in environmental samples

is mass spectrometry (MS), following chromatographic separation, with

internal standard (IS) calibration. In this approach (which was used in most of

the chemical analyses performed in the studies underlying this thesis)

standards are added that are analogous to the target compounds, i.e. have very

similar physicochemical properties, but are assumed to be absent in the

sample. Ideal choices, if available, are isotopologues (differing from analytes

only in isotopic composition, and used in quantification by “isotope-dilution

MS”). If added prior to extraction the IS will allow ready adjustment of the

results to compensate for sources of errors such as losses and matrix effects

during extraction and instrumental analysis. Isotopic labelled standards can

also be used as recovery standards (RS) added prior the instrumental analysis

(which also was used in most of the chemical analyses performed in the studies

underlying this thesis) to calculate the recovery of IS, i.e. the extent of losses

during the experimental work.

The chemical analyses, all based on accredited analytical methods or methods

validated in-house, were performed at qualified Swedish laboratories

experienced in analysis of the target compounds (Papers II-IV). The chemical

analyses of the FQs, OPs, PBDEs, PCAs, PCBz, PCDD/Fs and WHO-PCBs have

been performed by the author of this thesis. Detailed descriptions of the

chemical analyses applied in the studies reported in Papers I and V are

provided in the respective papers. The annual chemical analyses have been

performed at the same laboratories following the same substance-specific

protocols during the seven years of measurements, to ensure adequate

reproducibility (in this respect at least) for time-trend analysis (Paper IV).

General procedure for target analysis of sewage samples

Reliable analytical methods for measuring levels of hazardous compounds, e.g.

in sewage matrices, are needed for qualitative and quantitative analyses, which

provide information about the types of compounds (characterization and

identification) and the amounts of target compounds, respectively, that are

present in a sample. Direct analysis, with minimal or none clean-up, using e.g.

LC-MS/MS or purge-and-trap GC-MS is sometimes possible, while extensive

clean-up (often with several steps) is required for most of the OCs. The

selectivity of the instrument used for detection is highly associated to the use of

clean-up step(s). To provide an overview of the chemical analyses performed in

the studies this thesis is based upon, a general procedure for the preparation

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

26

(extraction, clean-up and fractionation) and instrumental analysis of the

sewage samples is given here. The main purpose of this procedure is to remove

co-extracted, interfering compounds while keeping the target compounds

intact in the final extract prior to instrumental detection.

Extraction

The purpose of an extraction is to efficiently extract (using a suitable extraction

solvent) the target compounds from the sample matrix. In this work, the

compounds were extracted using different techniques. In general, solid/liquid

extraction was used for solid samples and liquid/liquid extraction or solid

phase extraction (SPE) for water samples. Soxhlet extraction is a commonly

used extraction technique for POPs in solid matrices (U.S. EPA, 1994c), which

was used in several of the analyses. Pressurized liquid extraction (PLE) is a

modern alternative extraction technique (Richter et al., 1996) that was also

used. Before the sludge samples were subjected for PLE, they were freeze-dried

to achieve complete dryness (d.w. of 100%). SPE is commonly used to enrich

analyte and/or clean-up water samples and was used in some of the analyses.

Clean-up and fractionation

The sample extracts derived from these traditional (non-selective) extraction

techniques require extensive clean-up prior to the instrumental detection. The

purpose of the clean-up is to remove undesirable compounds such as lipids and

other interferences to decrease chemical noise and avoid interfering

compounds co-eluting in the instrumental analysis. Open column absorption

chromatography on sorbents such as silica (neutral or acid/base modified) and

Florisil® are widely used as clean-up for analysis of POPs. In cases when acid

modified silica was not preferable (due to the target compounds sensitivity to

acids), gel permeation chromatography (GPC) was used for macromolecule (e.g.

lipids) removal. In the analysis of PCDD/Fs and PCBs the extract were further

fractionated on activated carbon columns to avoid their interfering in the

instrumental detection due to the higher levels of PCBs present in the samples

than PCDD/Fs.

Instrumental detection and quantification

The prepared and concentrated (less than one mL) sample extracts, are finally

prepared for the instrumental analyses, which were mainly performed using

gas or liquid chromatography (GC or LC) coupled with (high or low resolution)

mass spectrometry (HRMS or LRMS). IS quantification was generally used,

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

27

often by isotope-dilution MS, as described earlier. Detailed information about

the analytical techniques applied and the overall analytical uncertainties are

summarized in Table 5.

Quality assurance and quality control

In order to evaluate the quality (accuracy and precision) of the acquired data,

established laboratory quality assurance and quality control (QA/QC)

procedures were used. Method blank samples were run, in parallel to all

samples, as controls (following the same analytical protocols) to ensure that

any contamination during preparation, extraction, clean-up and instrumental

analysis did not significantly influence the quantitative results. The target

compounds were considered to have been positively identified if their

chromatographic retention times corresponded to those of authentic reference

standards and their signal intensities were at least three times higher than the

limit-of-detection (LOD), which was defined as the limit-of-quantification

(LOQ). If the concentrations in the samples were lower than the LOQ values the

results were denoted as <LOQ.

Non-targeted screening using GCxGC-MS

In the study described in Paper V a less discriminatory procedure (fully

described in the paper) than the general protocol outlined above was applied to

sewage water, and the STP influent and effluent was characterized using

comprehensive two-dimensional GC (GCxGC) with time of flight MS (TOFMS)

detection. In GCxGC, two columns with different separation mechanisms are

used to maximize the separation of the target analytes. The material that elutes

from the first dimension (1D), often a non-polar column, is transferred to the

second dimension (2D), often a shorter narrow polar, semi-polar or shape-

selective column. In the non-polar 1D the analytes are separated based on their

volatility while the shorter 2D separates on specific interactions with the

columns’ stationary phase. The higher peak capacities obtained in GCxGC than

in one-dimensional GC is due to its complete separation in two, more or less

orthogonal, dimensions, thus improving the separation both between analytes

and between analytes and sample matrix components. The GCxGC modulator

(the key element of such an instrument) accumulates and focuses fractions

eluting from the 1D and rapidly re-inject them into the 2D.

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

28

Data evaluation

General calculations

Single-point IS calibration was generally used as quantification method of the

sewage contaminants. The amount of analyte in sample and recovery of IS were

calculated according to:

m, amount of analyte in sample; Area, peak area; mIS, mass of IS added to the sample prior extraction equivalent to the mass added to the quantification standard.

The sewage sludge concentrations were normalised to their dry weights (d.w.).

Approximately 5 g of the sludge was weighted and put in an oven at 105 C for

24 h. The water content is the difference in mass of the sludge before and after

oven drying.

The STP removal efficiency (RE) – defined as the proportion of a sewage

contaminant (or class of contaminants) eliminated, in total, via mechanical,

chemical and biological treatments in an STP – was calculated according to:

C, total concentration of analyte in effluent or influent water.

Mass flows (MFs, g d-1) of the target compounds were calculated from their

measured concentrations and estimates of mass flows of water and solids

throughout the STP at the sampling time (Papers I and II). Annual

environmental MFs (kg year-1) of the sludge contaminants were calculated from

their measured concentrations (median values) and the total national annual

production of sewage sludge (240 000 tonnes d.w. year-1; Swedish EPA, 2007)

(Papers III and IV).

standardAnalyte,sampleS,I

ISstandardIS,sampleAnalye,

AreaArea

mAreaAream

standardIS,sampleRS,

standardRS,sampleIS,

AreaArea

AreaArea (%) Recovery

totInfluent,

totEffluent,

C

C (%) RE

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

29

In the study presented in Paper V, semi-quantification methodology was used

to calculate the sewage contaminant concentrations:

C, concentration of analyte in sample; Area, peak area; mIS, mass of IS added to the sample prior instrumental analysis; VAq, sample, volume of water sample.

Moreover, the breakthrough in the STP (Paper V) – defined as the proportion

of a sewage contaminant not removed, in total, via mechanical, chemical and

biological treatments in the STP – was calculated according to:

C, total concentration of analyte in effluent or influent water.

Time-trend analysis

Log-linear regression analysis was used to determine if there were any

statistically significant time-trends in the sewage sludge concentrations over

the seven study years (Paper IV). The slope generated by this analysis reflects

the yearly percentage change, where a slope of ±10% means continuous annual

change of 10% corresponded to the initial concentration doubling (+) or

halving (-) within seven years. The statistical power was set to 80% (i.e. the

probability of reflecting true trends). Outliers in the data set may have arisen

because of an uncommon change in the physical environment, a change in

pollution load, or errors in the sampling or analytical procedure. Therefore, to

identify such suspected outliers, particular attention was paid to observations

further from the regression line than expected from the residual variance

around the line. Values greater or smaller than 3 times the difference between

the median and the 75th and the 25th percentile, respectively, were considered

outliers. These outliers were, in overall, not included in the statistical

evaluations.

sampleAq,sampleIS,

sampleIS,sampleAnalyte,

VArea

mAreang/LC )(

totInfluent,

totEffluent,

C

CghBreakthrou (%)

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

30

Principal Component Analysis

Multivariate statistical techniques, e.g. Principal Component Analysis (PCA), are

commonly used for detecting, extracting and visualizing patterns and trends in

large, complex data sets and thus (inter alia) generating easily interpretable

overviews of experimental results. PCA is a projection technique that reduces

the dimensions of such data sets, by summarizing the information in a reduced

set of orthogonal variables or vectors, known as principal components (PC1,

PC2,…, PCn). These variables can be used to identify similarities and groupings

among the samples and original variables. PCA can also be useful for detecting

suspected outliers and the variables that may influence deviations. PCA results

are presented as scores and loadings, which are superimposable and should be

evaluated together. A score plot illustrates the similarities and differences

between observations (samples) whereas a loading plot illustrates the

underlying reasons (related to contaminant concentrations) for the patterns in

the corresponding score plot. Objects close to each other in the score plot are

closely related while those far apart exhibit larger differences from each other.

PCA (as implemented in the SIMCA-P+11 package, Umetrics, Sweden) was used

in study III (Paper III) to explore the relationships between concentrations of

individual sludge contaminants (or groups of contaminants) and individual

STPs (or groups of STPs). In the last study (Paper V), it was used to detect

suspected outliers in the sewage contaminants data and to find distinct

groupings of sample matrices (clearly separated from each other). In both

studies, the data were mean centered and scaled to unit variance prior to the

PCA to give all parameters equal weighting.

4. SAMPLE COLLECTION AND CHEMICAL ANALYSIS

31

Table 5. Comparative data of the analytical techniques and quantifying uncertainties in the analyses of the compounds.

Class of compound Sub group

Analytical techniquea

Quantifying uncertainty

(%) Reference

Metals As, Cd, Co, Cr, Hg, Ni, Pb

Cu, V, Zn ICP- SFMS ICP- AES

± 20 ± 20-30

[1]b [2]b

Esters Phthalates

Adipates Organophosphorus compounds

GC-MS GC-MS GC-MS

± 20 ± 40 ± 30

CLc [3] [4]c

Pesticides Biocides

Insecticides, herbicides, and fungicides

GC-MS GC-MS

± 40 ± 40

[5] CLc

Hydrocarbons PAHs

Terpene (Limonene) GC-MS ATD-GC-FID

± 30 ± 40

[6]b

[7] Phenols Chlorophenols

Butylhydroxytoluene Triclosan 4-Nonylphenol

GC-MS GC-MS GC-MS GC-MS

± 20 ± 20 ± 20 ± 40

CLb,d CLc,e CLc

CLb

Organometals Organotin compounds ICP-MS ± 6-40 [8]c

Pharmaceuticals Fluoroquinolones

Trimethoprim

Tetracyclines NSAIDs Hormones

LC-MS/MS LC-MS/MS LC-TOF-MS GC-MS LC-TOF-MS

± 40 ± 40 ± 40 ± 40 ± 40

[9]c

[9]c

[10] [10] [10]

Siloxanes Methylsiloxanes ATD-GC-MS ± 40 [11] Fluorinated compounds

Perfluorochemicals LC-MS/MS ± 5-20 [12]f

Halogenated compounds

Polychlorobenzenes PBDEs Indicator-PCBs WHO-PCBs PCDD/Fs Polychlorinated alkanes

GC-MS GC-MS GC-MS GC-HRMS GC-HRMS GC-MS

± 30 ± 30 ± 40 ± 29 ± 29 ± 30

[13]c

[13]c

[6]b

[13]b

[13]b

[14]c,g

aICP, Inductively Coupled Plasma; SFMS, Sector Field Mass Spectrometry; AES, Atomic Emission Spectrometry; GC, Gas Chromatography; MS, Mass Spectrometry; ATD, Automated Thermal Desorption; FID, Flame Ionization Detection; LC, Liquid Chromatography; MS/MS, Tandem Mass Spectrometry; TOF, Time-of-Flight; HRMS, High Resolution Mass Spectrometry. bAccredited analysis. cIn-house validated analytical method. dCL, Commercial Laboratory. eBHT semi-quantitatively analyzed, the results are presented in benzylbenzoate-equivalents. fWith some modifications. gModification: 13C labelled PCB 188 was used as recovery standard instead of ε-HCH.

References: [1] U.S. EPA, 1994b; [2] U.S. EPA, 1994a; [3] IVL, 2005a; [4] Marklund et al., 2005; [5] IVL, 2006b; [6] Swedish EPA, 1990; [7] IVL, 2005b; [8] Kumar et al., 2003; [9] Lindberg et al., 2005; [10] IVL, 2006a; [11] IVL, 2005c; [12] Karrman et al., 2005; [13] Liljelind et al., 2003; [14] Reth et al., 2005.

32

33

The first study (Paper I) focused on the behaviour and fate during sewage

treatment, specifically treatment in the Umeå STP, of several representative

antibiotics – the FQs norfloxacin, ofloxacin and ciprofloxacin, the sulphonamide

sulfamethoxazole and trimethoprim. The sampling points are described in

Figure 4, Chapter 3. In this study the distribution of the analytes within the

STP’s process streams was analysed in detail; samples were taken from the

influent (aqueous and particles) and effluent as well as sludge following each

treatment step. The objectives were to determine concentrations and mass

flows of the target compounds throughout the process, and attempts were

made to predict concentrations and mass flows using consumption data.

In study II (Paper II), the objectives were similar, but the analytes were metals

and OCs (POPs and PPCPs). In addition, the robustness of commonly used STP

fate models for predicting the behaviour and fate of sewage contaminants was

assessed. In both studies, MFs of the target compounds were calculated from

their measured concentrations and estimates of mass flows of water and solids

throughout the STP at the sampling time. The STP removal efficiencies of the

compounds were also estimated, i.e. the levels found in effluent were compared

to levels in influent (aqueous and particles). Finally, an attempt was made to

assess whether the findings could be related to the compounds’

physicochemical properties or biodegradability. The preparation of samples,

calculations and assumptions made are fully described in the respective papers.

To obtain an overview of the general sludge quality in Swedish STPs, the mass

flow of sludge contaminants in them was broadly analysed in the third study

(Paper III). The objective was to perform a screening of metals, POPs, PPCPs

and other OCs in sludge from Swedish STPs with various characteristics

(descriptive data of the STPs are given in Table 3, Paper III). Further, possible

correlations were investigated between sludge contaminant levels and (i)

quantities nationally used and (ii) their physicochemical properties and

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

34

biodegradability in each of the treatment steps. Finally, the distibution patterns

of the contaminants between and within STPs were analyzed and potential

sources of contaminants detected in the sludge were identified. Detailed

information about the analytical techniques applied in these studies (Paper I-

III) is given in Table 5, Chapter 4. In the study presented in Paper III,

environmental mass flows of the sludge contaminants were calculated from

their measured concentrations (median values) and the annual production of

sewage sludge (in Sweden, 240 000 tonnes d.w. year-1; Swedish EPA, 2007),

assuming that all sludge generated is spread on land (a reasonable

approximation, since only small proportions are incinerated). These mass flows

were then compared to the national use statistics (Swedish Chemicals Agency,

2011) to assess the proportions of chemical substances used in the

technosphere that reach the STPs and associate with sludge.

Behaviour and fate of sewage contaminants

Antibiotics

Of the five investigated antibiotics only three (norfloxacin, ciprofloxacin and

trimethoprim) were detected at levels exceeding their LOQ. Trimethoprim was

completely dissolved in the aqueous phase, and its concentration and mass flow

were very similar in both influent and effluent (Figure 5, bottom), suggesting

that it is only marginally affected by the sewage treatment processes at Umeå

STP and is not appreciably sorbed to sludge. The opposite was found for the

FQs; about 80% of their total mass entering Umeå STP was attached to

particles, see Figure 5 (norfloxacin, top and ciprofloxacin, middle), which shows

the mass flows of all three antibiotics in both aqueous and solid phases, and

summarizes their fate during the treatment process. Umeå STP is located in the

northern part of Sweden, where the climate (and thus temperature of the

sewage) is cold. Since the temperature can strongly affect both biotic and

abiotic processes (notably biodegradation and partitioning between phases),

this may at least partly explain the high proportion of the FQs found sorbed to

sludge in influent water (raw sewage); somewhat higher than previously found

in a Swiss STP (33% of the FQs sorbed, sewage temperature 8°C higher; Golet

et al., 2003). The data displayed in Figure 5 also show that removal efficiencies

were high for the FQs (approximately 75% of the total amounts that entered

the STP left it sorbed to digested sludge), but virtually no trimethoprim was

removed. The findings of high removal efficiencies for the FQs are consistent

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

35

with the cited Swiss study. Another Swiss study (Gobel et al., 2005) also

detected trimethoprim solely in aqueous phases, but in contrast to the findings

for Umeå STP levels of trimethoprim significantly decreased during treatment.

Figure 5. Fate of norfloxacin (top), ciprofloxacin (middle) and trimethoprim (bottom) during sewage treatment at Umeå STP. Mass flows, in grams per day, are shown as mean values and standard deviations over three sampling days, except for raw sewage particles. The amounts found in final effluent and digested sludge are expressed in percentages relative to the total amounts (sum in raw sewage water and particles). Theoretically calculated mass flows are shown in italics. From Paper I.

Raw sewage

Norfloxacin

Biological

treatment

Anaerobic

digestion

37±7

Digested sludge

Final effluent41100%

72%

3.4%

Sand/fat removal

Mechanical

and

chemical

treatment

8.7±1

16

3.4±2

8.5

30±13

4.5±0.6

1.7±0.4

Excess sludge

External sludge

1.3±0.2

43±5

Methane

CO2

6

Raw sewage

Ciprofloxacin

Biological

treatment

Anaerobic

digestion

32±2

Digested sludge

Final effluent33100%

77%

3.6%

Sand/fat removal

Mechanical

and

chemical

treatment

6.5±0.2

6

2.9±1

8.7

31±10

5.2±0.5

1.4±0.3

Excess sludge

External sludge

1.9±0.2

56±9

Methane

CO2

24

Raw sewage

Trimethoprim

Biological

treatment Final effluent100% 104%

Mechanical

and

chemical

treatment

41±13 32±10 42±21

Aqueous phase

Solid phase

x±y g/d

x±y g/d

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

36

In the prediction assessments, the predicted environmental concentration

(PEC) and mass flow (PEMF) of each antibiotic were calculated and compared

to the corresponding measured environmental concentration (MEC) and mass

flow (MEMF). The PECs and MECs are presented in Table 4 of Paper I, while

the PEMFs and MEMFs are shown in Figure 6. The concentration predictions

were not completely satisfactory; the correlations between predicted and

measured levels for norfloxacin were very good, but the PECs (and hence mass

flows) were considerably underestimated for trimethoprim and overestimated

for ciprofloxacin.

Figure 6. Mass flows of antibiotics: calculated using national consumption data representing excretion in urine (NPEMF Ref); calculated using data on their consumption within Umeå municipality (MPEMF Ref); and measured in raw sewage water (MEMF RSW). From Paper I.

Other organic compounds and metals

In the metal and OC screening, 75 compounds were initially investigated, but

only 21 (28%) fulfilled defined criteria for further analysis (positive detection

in all six sample matrices). Thus, the following discussion focuses on the

removal efficiency (called the elimination rate in Paper II) and associated

parameters of those 21 analytes. In general, the concentrations reflected the

quantities of the respective substances used in Sweden; sewage levels of some

metals, PPCPs and polymer additives were high, while those of diffusively

emitted halogenated contaminants such as PCDD/Fs, PBDEs and PCBs were

lower. This study also revealed, as expected, that the removal efficiency was

higher for lipophilic than for water soluble compounds. The removal

efficiencies (REs), measured and predicted using the STPWIN module of the

0

5

10

15

20

25

30

35

40

45

Norfloxacin Ciprofloxacin Trimethoprim

g/d

NPEMF Ref

MPEMF Ref

MEMF RSW

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

37

U.S. EPA EPI Suite™ (EPI Suite™, 2007) and percentages adsorbed to sludge (SA)

of the analytes (except for the metals Co, Cu, Ni and Zn) are presented in

Figures 7 and 8, respectively.

The organophosphorus flame retardant and plasticizer (OP) 2-ethylhexyl-

diphenyl phosphate (EHDPP) and tricresyl phosphate (TCP) were found to be

efficiently removed (RE, 81% and 96%, respectively). The remaining aliphatic

OPs seemed to pass straight through the STP, probably due to their high water

solubility. The chlorinated OPs are also highly water soluble and Marklund et al.

(2005) have shown that there is little or no removal of these substances in

STPs, i.e. they generally pass straight through. Most of the pharmaceuticals and

antibacterial agents were also efficiently removed during sewage treatment.

Ciprofloxacin was the only one of three analysed FQs that was detected in all

sampled matrices (RE, 97%, while REs for the other two FQs, norfloxacin and

ofloxacin, were ca. 99%). Triclosan was also highly removed (75%).

Figure 7. Removal efficiencies (%) of the sewage contaminants detected in all matrices sampled at Umeå STP; measured, dark bars, and predicted (using the STPWIN module of the U.S. EPA EPI Suite™ software package), light bars. Abbreviations: DEHP, Di-(2-ethylhexyl) phthalate; TBEP, Tris(2-butoxyethyl) phosphate; TBP, Tributyl phosphate; TDCPP, Tris(1,3-dichloro-2-propyl) phosphate; TPP, Triphenyl phosphate; EHDPP, 2-Ethylhexyldiphenyl phosphate; MBT, Monobutyltin; DBT, Dibutyltin.

0

10

20

30

40

50

60

70

80

90

100

PC

B 7

7

PC

B1

05

PC

B 1

18

PC

B 1

56

PC

B 1

67

PB

DE

47

PB

DE

99

DE

HP

TB

EP

TB

P

TD

CP

P

TPP

EH

DP

P

Cip

rofl

oxa

cin

MB

T

DB

T

Tri

clo

san

%

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

38

To obtain an idea of the contaminants’ sludge adsorption percentage we

assumed that the concentrations of the compounds in primary sludge equalled

their respective concentrations in effluent particles. Further, by using the mass

flow (MF) values, their sludge adsorption (SA, see Figure 8) values were

calculated according to:

Most of the ciprofloxacin and triclosan seemed to sorb to sludge (SA, 78% and

82%, respectively). High adsorption (96%) was also found for DEHP. The

results of this study indicate that several phthalates are degraded during

sewage treatment, as also reported by Roslev et al. (2007) and Dargnat et al.

(2009), who found that approximately 90% of phthalates are degraded in STPs.

Ling et al. (2008) also reported that most of the phthalates are biodegradable in

sludge.

Figure 8. Measured, dark bars, and predicted (using the STPWIN module of the U.S. EPA EPI Suite™ software package), light bars, percentages sorbed to sludge (SA) of contaminants detected in all sampled matrices at Umeå STP. For meanings of abbreviations, see Figure 7. From Paper II.

totEffluent,primaryge,Slud

primaryge,Slud

MFMF

MFSA (%)

0

10

20

30

40

50

60

70

80

90

100

PC

B 7

7

PC

B 1

05

PC

B 1

18

PC

B 1

56

PC

B 1

67

PB

DE

47

PB

DE

99

DE

HP

TB

EP

TB

P

TD

CP

P

TPP

EH

DP

P

Cip

rofl

oxa

cin

MB

T

DB

T

Tri

clo

san

%

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

39

Of six investigated OTCs only two (monobutyltin, MBT, and dibutyltin, DBT)

were detected in all matrices (RE, 41 and 77%, respectively). The metals Co, Cu,

Ni, and Zn appeared to be released into the recipient water in approximately

the same total concentrations (low mg L-1) as they entered the STP (Table S3,

Supporting information for Paper II). In contrast, As, Cd, Cr, Hg and Pb (RE,

92±2%) were detected at similar concentrations in both the solid phase of raw

sewage and sludge. Thus, Co, Cu, Ni and Zn were present in the dissolved phase;

while As, Cd, Cr, Hg and Pb were primarily associated with particles. In general,

the examined substances seem to be unaffected by anaerobic digestion since

their concentrations and MFs were similar before and after the digestion

process.

To facilitate thorough analysis of the behaviour and fate in the STP of the

sewage contaminants (detected in all matrices), their proportions in aqueous

and solid phases of raw sewage, effluent and sludge (normalized to their total

mass flows in raw sewage) were calculated and graphically visualized (Figures

9 and 10). The OP tributyl phosphate (TBP) was almost exclusively dissolved in

the aqueous phase (influent and effluent), EHDPP was mainly sorbed to solid

phases, while the partitioning of the remaining OPs was intermediate. The

detected PCBs appeared to have higher affinity for the solid than the aqueous

phases (influent and effluent). The PBDEs 47 and 99 entered the STP

partitioned approximately equally between aqueous and solid phases, but left,

after sewage treatment, mainly in the solid phase, adsorbed to effluent particles

and sludge.

The OTCs MBT and DBT were highly associated with the aqueous phase of the

STP influent, but were quite evenly distributed between the aqueous and solid

phases after sewage treatment. The four metals, Co, Cu, Ni and Zn, were almost

totally distributed in the aqueous phases (influent and effluent) when passing

through the STP, as mentioned above. No information was obtained on the

distributions of triclosan and DEHP between aqueous and solid phases in raw

sewage, because only their total concentrations were measured. However,

these substances appeared to leave the STP primarily bound to sludge.

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

40

Figure 9. Fractions of the analysed compounds (detected in all sampled matrices) in aqueous (IN H2O) and solid (IN Part) phases of the total mass flows of raw sewage at Umeå STP. For meanings of abbreviations see Figure 7. From Paper II.

0% 20% 40% 60% 80% 100%

Triclosan

TBP

TDCPP

TBEP

TPP

EHDPP

DEHP

Ciprofloxacin

PCB 77

PCB 105

PCB 118

PCB 156

PCB 167

PBDE 47

PBDE 99

MBT

DBT

Co

Cu

Ni

Zn

IN H2O

IN Part

measured as total concentration in raw sew age

measured as total concentration in raw sew age

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

41

Figure 10. Fractions of the analysed compounds (detected in all sampled matrices) in aqueous phase (OUT H2O), solid phase (OUT Part) and dewatered digested sludge (Sludge) of the total mass flows in raw sewage at Umeå STP. Solids in effluent water were only analysed for WHO-PCBs and PBDEs. Asterisked values (*) indicate total concentrations in effluent water, i.e. both aqueous and solid phase. For meanings of abbreviations see Figure 7. From Paper II.

The prediction of removal efficiencies and sludge adsorptions by the STP fate

model designed to predict removal efficiencies and sludge adsorption

percentages provided poor predictions of percentages of polar compounds

sorbed to sludge. Among compounds with similar water solubility, the model

may either grossly under- or over-estimate the fraction sorbed to sludge. The

SA was underestimated for ciprofloxacin, MBT and DBT, possibly due to effects

of polar interactions, such as ion-dipole and hydrogen bond interactions,

between the solutes and sludge. Such interactions are more difficult to predict

0% 20% 40% 60% 80% 100%

Triclosan*

TBP

TDCPP

TBEP

TPP

EHDPP

DEHP*

Ciprofloxacin

PCB 77

PCB 105

PCB 118

PCB 156

PCB 167

PBDE 47

PBDE 99

MBT

DBT

Co

Cu

Ni

Zn

OUT H2O

OUT Part

Sludge

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

42

than others, e.g. dispersive interactions, which are the predominant

intermolecular forces in interactions between lipophilic compounds and sludge.

In contrast, the SA percentages of the water soluble OPs were overestimated,

which is more difficult to explain, but the STPWIN modules were developed

using data for legacy (primarily lipophilic) pollutants, and the physicochemical

properties of the OPs may fall outside the valid model domain. Further studies

are needed to corroborate and explain these findings.

To conclude, the climate at an STP’s location inevitably influences the

temperature of the sewage it treats, and thus the behaviour of chemical

substances during sewage treatment, notably the biodegradation and

distribution of contaminants between water and particulate matter. This may

at least partly explain the inefficient removal of certain polar compounds in the

investigated cold climate STP, which indicates required improvements of the

STP’s processes. Predictions of environmental concentrations and mass flows

of antibiotics, based on consumption data and World Health Organization

(WHO)-defined daily doses (DDD), can provide useful indications of their

environmental loads (Paper I). The STPWIN fate model used in study II (Paper

II) yields total removal efficiencies (RE) and individual values for three

contributing removal processes: biodegradation, sorption to sludge (SA) and

air stripping. Generally, the measured SA-values agreed better than the

corresponding RE-values with the STPWIN estimates.

Swedish sludge quality

The extensive screening reported in Paper III provides information about mass

flows of 282 compounds (in 2004, unless otherwise stated) used in Sweden to

sewage sludge. The total and relative concentrations of the sewage

contaminants (Table 4 and S3, Supplementary data; Paper III) were generally

found to be quite uniform on a d.w. basis, indicating that they largely originate

from broad applications and diffuse dispersion rather than from (industrial)

point sources, even though industries also contribute to chemical constituents

in the sludge. Lower levels of the contaminants (35% lower, on average) were

detected in sludge from STPs processing large quantities of water from food

industries (rich in organic substances and lean in pollutants) or household

sewage (with low levels of industrial pollutants) than in sludge from the other

STPs. In order to obtain an overview of the sludge contaminants we calculated

the median total concentration of each group of compounds detected at each

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

43

STP (Figure 11). The metals were found in the highest total concentrations (five

orders of magnitude higher than those of the least abundant detected analytes:

PCDD/Fs). Similar concentration patterns were also found in study IV (in 2010;

Paper IV), indicating that the sludge quality is quite constant in terms of

contamination levels.

Figure 11. Median total concentrations (logarithmic scale) of each measured group of metals, persistent organic pollutants, pharmaceuticals and personal care products, and other organic contaminants in sludge from sewage treatment plants (STPs) in Sweden. The error bars correspond to the ranges of total concentrations (n=7 STPs, unless otherwise indicated). Abbreviations: PCAs, Polychlorinated alkanes; FQs, Fluoroquinolones; 4-NP, 4-nonylphenol; TCs, Tetracyclines; BHT, Butylhydroxytoluene; OPs, Organophosphorus compounds; PAHs, Polycyclic aromatic hydrocarbons; PBDEs, Polybrominated diphenyl ethers; OTCs, Organotin compounds; NSAIDs, Non-steroid anti-inflammatory drugs; CPs, Chlorophenols; I-PCBs, Indicator-PCBs; PCBz, Polychlorobenzenes; PFCs, Perfluorochemicals; PCDD/Fs, Polychlorinated dibenzo-p-dioxins and -furans. From Paper III.

Pattern of use and mass flows

As mentioned in Chapter 2, the uses of consumer chemicals will affect the

quality of sludge generated in STPs. In order to identify use-related, STP

treatment-related and other factors affecting sludge quality we compared the

quantities used in Sweden and the calculated annual mass flows (MFs) for

sludge (Table 4 in Paper III). Large quantities of metals are used in Sweden,

0

1

2

3

4

5

6

7

Group of compounds

Met

als

Ph

thal

ate

s

PC

As

Silo

xan

esa

Bio

cid

es

FQs

Tric

losa

n

TCsb

Pe

stic

ide

s

BH

T

OP

s

PAH

s

PB

DEs

OTC

s

Lim

on

en

eb

NSA

IDsb

CP

s

Ad

ipat

esb

I-P

CB

s

PC

Bz

PFC

s

WH

O-P

CB

s

PC

DD

/Fs

4-N

P

log

Co

nc.

(µg

kg-1

d.w

.)

a n = 3 STPsb n = 2 STPs

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

44

and this was reflected in high environmental MF (190 tonnes year-1). Other

abundant groups of compounds (MFs>250 kg year-1) detected were PPCPs, see

Figure 12, which are used in ways that inevitably lead to release to the sewer

system. Many of these PPCPs (FQs, tetracyclines, 4-nonylphenol, triclosan and

siloxanes) have high tendencies to sorb to sludge (Buyuksonmez and

Sekeroglu, 2005; IVL, 2005c; Lindberg et al., 2006; Ying and Kookana, 2007).

Figure 12. Percentages of the compounds found (recovered) in the sewage sludge relative to amounts used. For meanings of abbreviations see Figure 11.

High MFs (>10 tonnes year1) were also found for two groups of high volume

plastic additives: phthalates (plasticizers) and PCAs (flame retardants and

plasticizers). These compounds may reach the sewer system through

evaporation from plastics (at low emission rates), partitioning to dust and

cleaning of indoor environments. Plastic materials may make substantial

contributions to levels of phthalates and PCAs in sewage sludge, despite the low

emission rates, due to the large stocks of plastics in Sweden. Other flame

retardants found sorbed to sludge include the PBDEs, which were found in

remarkably high proportions relative to quantities used (like the PCAs); ca. 10-

fold higher than corresponding proportions of phthalates, flame retardants and

plasticizer OPs. All four of these groups of compounds have low volatility (low

emission rates), which makes it difficult to explain the high proportions found

in sludge from their physicochemical properties. However, a contributory

63

51

41

29

17

4.1

3.7

0.9

1

0.4

6

0.2

1

0.1

4

0.1

1

0.0

6

0.0

6

0.0

4

0.0

4

0.0

4

0.0

4

0.0

1

0.0

02

0

10

20

30

40

50

60

70

FQs

TC

s

4-N

P

Tri

clo

san

Silo

xan

es

PC

As

PB

DE

s

Me

tals

Lim

on

e

Bio

cid

es

BH

T

PC

Bz

Pe

stic

ide

s

OP

s

Ph

tha

late

s

OTC

s

NSA

IDs

PFC

s

PA

Hs

Ad

ipat

es

%

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

45

factor may be the limitation of the product register (described in Chapter 2).

PCAs and PBDEs probably enter the country as unrecorded additives in

imported textiles, plastics, computer and other electronic goods etc., thus the

recorded quantities are probably much lower than the amounts present in the

Swedish technosphere. The remaining compounds, detected in the sludge in

relatively low concentrations (Figure 11), stem from multiple, often diffuse

sources, such as traffic and long-range air transport, reaching the STPs via

storm water systems, hence comparisons with use statistics for them is not

meaningful.

Factors affecting mass flows

In addition to pollution loads at STPs several other factors (mentioned in

Chapter 2) affect the concentrations of contaminants in sewage sludge,

including their tendencies to evaporate or be biodegraded during the treatment

process, water solubility and sludge affinity (e.g. if they have very low affinity

they are likely to pass straight through a STP). Therefore, the physicochemical

properties of the compounds and their biodegradability must be considered to

understand the findings and draw conclusions regarding the sludge

contaminants’ behaviour in STPs.

Evaporation

The intrinsic volatility of chemical substances may influence their mass flows at

several life-cycle stages, notably it may strongly affect initial emission rates of

additives in consumer products and losses caused by evaporation in STPs. To

assess possible effects of contaminants’ volatility on their mass flows we

investigated the relationship between the molecular weights of plastic

additives and percentages recovered in sludge, and found a linear relationship

(Figure 13). Thus, evaporation in the STPs may affect their mass flows more

than their molecular emission rates from articles. However, the pattern may

also be due to other factors, such as high water solubility that may cause

contaminants such as OPs that have relatively high water solubility (>5mg L-1)

to pass STPs, as described below. It is also generally accepted that compounds

with high molecule weight (and hence low vapour pressures: Henry´s law

constant <10-5 atm m3 mol-1) e.g. PBDE 209 are primarily released through

particulate emissions; and such wear particles (if they reach the STP) will then

end up in sludge.

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

46

Figure 13. Molecular weight (Mw g mol-1

) vs. percentage recovered (%) in sludge of plastic additives (plasticizers and/or flame retardants), R

2=0.94 (TCPP excluded). OPs, organo-

phosphorus compounds (TBP, tributyl phosphate; TCEP, tris(2-chloroethyl) phosphate; TPP, triphenyl phosphate; TCPP, tris(2-chloroisopropyl) phosphate; TDCPP, tris(1,3-dichloro-2-propyl) phosphate); DEHA, di-(2-ethylhexyl) adipate; Phthalates (DEHP, di-(2-ethylhexyl) phthalate; DINP, di-iso-nonyl phthalate; DIDP, di-iso-decyl phthalate); PBDE #209, decabrominated diphenyl ether. From Paper III.

However, evidence of considerable evaporative losses in STPs was found for

cyclic methylsiloxanes. The proportion of their quantities used that reach STPs

and sorb to sludge seems to strongly depend on their vapour pressure, which

decreases with the number of siloxane units. Proportions of octa- (D4), deca-

(D5) and dodeca-methylcyclotetrasiloxane (D6) recovered were 1.3%, 17% and

54%, respectively. The losses may occur either during biological sewage

treatment or sludge digestion. The latter process is known to result in tainted

biogas that causes deposits in boilers fed such fuel (Dewil et al., 2006; 2007).

Similarly, volatilization is probably the reason for the relatively low recovery of

limonene.

Biodegradation

The recovery of the non-steroid anti-inflammatory drugs (NSAIDs) was low

(unlike that of the other PPCPs), possibly because they completely dissolve in

aqueous phases and thus may be readily biodegraded and/or pass straight

though the STPs. However, the latter explanation conflicts with the relatively

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

200 300 400 500 600 700 800 900 1000

Re

cove

red

(%)

Mw (g mol-1)

OPs Phthalates

Re

cove

red

(%) P

BD

E # 20

9

PBDE # 209

TCPP

TBPTCEP

TPP

TBEP

DEHP

DINP

DIDP

DEHA

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

47

high recovery of FQ antibiotics, which are also quite water soluble. Further, a

recent study found that removal efficiencies of NSAIDs vary considerably

among Swedish STPs, from moderate (32% for diclofenac,) to high (65-90% for

ibuprofen, naproxene and ketoprofen) (IVL, 2006a). The cited study also

concluded that the removal efficiency tends to be lower in STPs located in the

northern part of Sweden, possibly due to the lower water temperatures (and

lower biological activity).

Regarding the OPs, biodegradation may also be responsible for the low

observed recovery of TBP in sludge (Figure 13). Compared to tris(2-

chloroisopropyl) phosphate (TCPP), TBP should theoretically sorb strongly to

sludge due to its lower water solubility, but its recovery in sludge was 10-fold

lower. However, TBP and other aliphatic OPs are known to be more degradable

than aromatic OPs (e.g. triphenyl phosphate, TPP), and chlorinated OPs (e.g.

TCPP) are most persistent (Saeger et al., 1979; WHO, 1991a; 1991b; 1998).

Water solubility

Much lower percentages of OPs, relative to their national use, were found in the

sludge than of PCAs and PBDEs, although they have similar applications. This

may be partially due to recent substitution of the latter by OPs, which will have

immediately influenced the use statistics, but only slowly affect the levels in

sludge (due to their long lifetimes and large stocks in use). However, OPs also

generally have higher water solubility (and biodegradability) than PBDEs,

hence larger proportions of OPs may be degraded or pass straight through

STPs. Chlorinated OPs such as tris(2-chloroethyl) phosphate (TCEP) and TPP

are both persistent and water soluble, and have been shown to pass through

STPs to a great extent (Marklund et al., 2005).

Point sources

As mentioned in Chapter 4, the multivariate data analysis technique PCA was

used to obtain an overview of the relationships between concentrations of

compounds (or group of compounds) in the sampled matrices and the STPs.

The model generated only includes the contaminants that were detected in all

seven selected STPs and concentrations below the LOQ were set to half LOQ.

The results (Figure 14a) indicate that all of the STPs except STP E have similar

contaminant profiles, since they cluster near the origin of the score plot. Among

these STPs, two groupings can be seen, indicating that STPs C and G generate

sludge with lower overall contaminant levels than the others. The

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

48

corresponding loading plots (Figure 14b-e) reflect the underlying reasons for

the trends, and thus provide important indications of the factors influencing the

distribution patterns in the score plot. Sludge from STP E seems to have had

higher proportions of most PFCs (Figure 14b), various pesticides (Figure 14c),

hexachlorobenzene (HCBz), highly chlorinated PCDD/Fs (Figure 14d), 4-

nonylphenol (4-NP) and PBDE 209 (Figure 14e), possibly because textile

factories (in which PFCs may be used during their manufacturing processes, or

present in imported material they use) are connected to STP E. The presence of

highly chlorinated PCDD/Fs in the sludge may be related to use of

pentachlorophenol as a fungicide, e.g. during the storage or transport of fabrics.

This is in agreement with a study by (Hedman et al., 2007), who concluded that

the textile fraction of municipal solid waste contains high percentages of total

PCDD/Fs. However, it should be noted that the Swedish textile industry is no

longer using perfluoroalkylsulfonates (perfluorooctane sulfonate, PFOS;

perfluorodecane sulfonate, PFDS; and perfluorohexane sulfonate, PFHxS)

during manufacturing. An associated finding was that sludge from STP E

contains similar levels of PFOS as the other STPs. In fact, more perfluoro-

alkylsulfonates were found in sludge from the two largest STPs (A and B) and

STP D, than from STP E. Based on these findings, my colleagues and I are

inferred that the primary current source of PFCs in sewage sludge is their

(unrecorded) content in imported articles. Moreover, high usage of sports and

functional clothing (often containing PFCs/antibacterial agents) in the cities

these STPs serve may also contribute to elevated levels of these compounds in

their sludge.

In addition to the high levels of perfluoroalkylsulfonates in sludge from STPs A,

B, and D, they also contain large proportions of metals, antibacterial agents

(triclosan and OTCs) and two phthalates (DEHP and di-iso-nonyl phthalate,

DINP, used as plasticizers in PVC). One can only speculate why high levels of

these compounds were found in the sludge from these STPs, but they are all

located in rapidly growing cities, thus high traffic intensity and newly

constructed buildings may be reasons for the high levels of metals and

phthalates. The elevated levels of zinc and lead may stem from brake linings of

motor vehicles (Hjortenkrans et al., 2007) and metal plated roofs, and the

phthalates from building materials. Although DEHP has mainly been

substituted by DINP since early 2000 (Petersson Lars, 2004) relatively high

levels (mg kg-1 d.w.) were found in the sludge, possibly at least partly due to the

large amounts of the chemical in the technosphere, and hence considerable

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

49

time-lag between its substitution and observable changes in sewage levels.

Industrial production of vinyl flooring was identified as a possible contributor

to the elevated levels of DEHP in STP D.

The lowest levels of sludge contaminants generally were found in the two STPs

C and G, but relatively high proportions of the fungicide propiconazole, which is

primarily applied to barley crops. These findings can probably be related to the

situation of these STPs in agricultural areas. A possible contributor to the

propiconazole found in sludge from STP C may also be a major food-processing

plant in its vicinity.

To conclude, although quite similar levels and distribution patterns of

contaminants were found among the investigated STPs, some minor variations

were detected using a multivariate approach (PCA), notably in the distribution

patterns of PFC in sludge, which could be related to textile industries (STP E),

and the presence of propiconazole in sludge associated with agricultural

activities (STPs C and G). In general, concentrations and distribution patterns of

sludge contaminants in Swedish STPs seem to be independent of the location,

size and treatment techniques applied in the plants, or the types of human

activities that affect the waste streams they handle. Some (weak) correlations

were found between the national use statistics and levels of the contaminants

in sewage sludge.

5. STP REMOVAL EFFICIENCY AND SLUDGE QUALITY

50

Figure 14. Principal Component Analysis (PCA) plots displaying patterns in levels of contaminants in sewage at the selected STPs, based on measured concentrations of the compounds analysed in all STPs (n=7), with levels below the limit-of-detection, LoD, were set to half the LoD. The first and second principal components (PC1 and PC2) explained 34% and 21%, respectively, of the total variance in the data. a: score plot showing relationships between the Swedish sewage treatment plants (STPs). b-e: loading plots showing the corresponding relationships among the metals, persistent organic pollutants (POPs), pharmaceuticals and personal care products (PPCPs) and other organic contaminants. For compound abbreviations, see Table S1, Supplementary data of Paper III. The three congested areas (boxes with broken lines) include: PFDoA, PFOA, PFDA, PFUnA, PFNA, PFTrDA, PFTeDA, PFHpA (panel b); ETPARAB, BUPARAB, BEPARAB, RESORCINOL, PROPARAB (panel c); and 1234789-CDD, 1234678-CDF, 123678-CDD, 2378-CDF, MCCP, OCDF, 14CBz, HCBz (panel d). From Paper III.

-0.2

-0.1

0.0

0.1

0.2

As

Cd

Co

Cr

Cu

HgNiPb

V

Zn

DEP

DBP

BBP

DEHP

DNOP

DIDP

DINP

2MERCAPTOB

KLORKRESOL

DDMAC

PROPICONA

RESORCINOL

MEPARAB

ETPARAB

PROPARABBUPARABBEPARAB

PAHsum

-0.2

-0.1

0.0

0.1

0.2

123478-CDD

123678-CDD

1234789-CDD

OCDD

2378-CDF

234678-CDF

1234678-CDF

1234789-CDF

OCDFPCB 77

PCB 126PCB 169

PCB 105PCB 118

PCB 156

PCB 15714CBz

12CBz

124CBz1235+1245CBz1234CBz

PCBz

HCBz

SCCP

MCCPLCCPPCB7

-0.2

-0.1

0.0

0.1

0.2

MBT

DBT

TBT

Nor

OflCip

BHT

2-CP26-CP

24+25-CPPCP

TCS

TBP

TCEPTCPP

TDCPP

TBEP

TPP

PBDE 28

PBDE 47

PBDE 99PBDE 153 PBDE 154

PBDE 183

PBDE 209

4NP

A: Stockholm – large, industry (mix)

B: Gothenburg – large, industry (mix)

C: Eslöv – industry (food)

D: Umeå – hospital

E: Borås – hospital/industry (textile, chemical)

F: Alingsås – industry (laundry)

G: Floda – household

PC1

PC

2

a)

-0.15 -0.10-0.20 0.10 0.200.150.05-0.05 0

b)

c)

PC1

PC

2

-0.15 -0.10-0.20 0.10 0.200.150.05-0.05 0

PC

2

PC1

d)

PC

2-0.15 -0.10-0.20 0.10 0.200.150.05-0.05 0

PC1

e)

-0.15 -0.10-0.20 0.10 0.200.150.05-0.05 0

PC

2

PC1

23478CDF

123CBz

&DMP

51

-

Several reviews have compiled global monitoring data of sludge contaminants

during the last decade (Clarke and Smith, 2011; Harrison et al., 2006; Law et al.,

2006; Xia et al., 2005). As mentioned earlier, in this time-frame the Swedish

EPA started a program to systematically sample, analyse and archive sewage

sludge. Germany and Switzerland have also started to discuss a routine

program for monitoring and archiving sludge samples and STP effluents (Rudel

et al., 2010). However, to our knowledge, no systematic studies of temporal

trends of extensive sets of sludge contaminants have been previously

published. Therefore, in study IV (Paper IV), time-trends of levels of metals,

POPs, PPCPs and other OCs, in Swedish STPs based on seven years of

measurements, were analysed. Descriptive data of the STPs and the analytical

techniques applied are presented in Table 4 (Chapter 3) and Table 5 (Chapter

4), respectively. Although a seven-year sampling period may be too short for

robust analysis, it should be sufficient to at least indicate directions of potential

trends.

Major aims of this study were to determine if the within-year variability in

contaminant concentrations in sludge samples from Swedish STPs was

sufficiently low to allow time-trend studies over reasonable time-spans and to

(if so) identify statistically significant temporal trends in concentrations of the

investigated sludge contaminants. Any established time-trends were

considered in relation to official attempts to reduce the quantities of harmful

substances released into the environment (e.g. by reducing use of regulated or

questioned chemical substances in both industrial applications and household

articles). Use statistics of the target compounds were retrieved from the

product register (Swedish Chemicals Agency, 2011). A further aim was to

evaluate if these attempts have been successful, by seeking discernible trends

in sewage levels of substances that have recently been substituted by others.

Identification and characterisation of such time-trends may facilitate the design

of future Swedish environmental sludge monitoring programs, in terms of

6. TIME-TREND ANALYSIS

52

variables such as the number of STPs to monitor, sampling frequency, phased-

out (and phased-in) substances to monitor, etc.

Mass flows and time-trends

Environmental mass flows of sludge contaminants

Of 126 compounds that have been analysed annually during these seven years,

only 77 fulfilled the defined criteria (presented in Paper IV, along with an

extensive description of the statistical data evaluation). Annual quantities used

nationally in Sweden and estimated overall mass flows of the 77 contaminants

are given in Tables 1 and 3 (Paper IV), respectively. Statistical evaluation of the

final data set detected significant time-trends for 18 sludge contaminants, 23%

of the compounds fulfilling the criteria, representing almost all compound

groups, with only one or a few significant compounds in each group. The annual

national mass flows were calculated, based on median concentrations of the

sludge contaminants from nine STPs in 2010 and the total national annual

production of sewage sludge (in Sweden, 240 000 tonnes d.w. year-1; Swedish

EPA, 2007). The results clearly show that there are very large differences in

environmental mass flows among the various classes of sludge contaminants,

metals (220 000 kg d.w. per year-1) and PCDD/Fs (0.16 kg d.w. year-1) being the

most and least abundant, respectively (Table 3 in Paper IV).

Variability in sludge contaminant concentrations

In order to assess the feasibility of monitoring contaminants in sewage sludge

for time-trend analysis and tracking emissions of chemical substances

circulating in the technosphere, the variability of the sludge contaminant levels

was evaluated. It was estimated that it would take 5 to 26 years to track an

annual change of 10% with a power of 80% (the probability to reveal true

trends) for the compounds, see Table 4 in Paper IV. The variability was lowest

for the OCs analysed using isotope-dilution MS (as described in Chapter 4) and

the metal cobalt. However, for many of the significant sludge contaminants it

would be possible to detect a 10% concentration change over the time-interval

of seven years, see Figure 15, since the diverse chemical contents of the sewage

matrices were less variable than may have been expected, given their

complexity and the large number of influential variables. In conclusion, the

6. TIME-TREND ANALYSIS

53

results indicate that sewage sludge is a promising matrix for time-trend

analysis.

Figure 15. Estimated number of years required for detecting, with a statistical power of 80%, annual 10% changes in levels of the following substances in STP streams: TDCPP, Tris(1,3-dichloro-2-propyl) phosphate; TBEP, Tris(2-butoxyethyl) phosphate; PFDoDA, Perfluoro-dodecane acid; PFOSA, Perfluorooctane sulfonamide; 124CBz, 1,2,4-trichlorobenzene; 14CBz, 1,4-dichlorobenzene; MBT, Monobutyltin; DBT, Dibutyltin; MCCP, medium chain chlorinated paraffins; MD2M, Decamethyltetrasiloxane; MD3M, Dodecamethyltetrasiloxane; MDM, Octamethyltrisiloxane. *Compounds that showed significant time-trends prior to elimination of suspected outliers.

Statistically significant time-trends

Eighteen of the 77 compounds analysed exhibited significant time-trends, and a

further seven in the original regression analysis, i.e. prior to elimination of

suspected outliers. The analysed compounds are all listed in Table 3 in Paper

IV; the 18 showing significant time trends highlighted in bold, and the seven

additional compounds marked with an asterisk.

Most of the contaminants showing significant time-trends (75%) decreased

annually by 5-65% during the study years, whereas increases of 13-56% per

year were estimated for the others (Table 4 in Paper IV). To prevent the

development or spread of resistance to antibiotic, e.g. FQs, their use should be

balanced and they should not be over-prescribed. This precaution should result

in their levels decreasing in sewage sludge and other environmental matrices.

26

1918

17 17 1716

15

12 12 1211 11 11

109 9 9 9

8 8 8

6 65

0

5

10

15

20

25

30

TD

CP

P*

Tri

clo

san

TB

EP*

PFD

oD

A*

PFO

SA

12

4CB

z

14

CB

z

PB

DE

99*

Cip

rofl

oxa

cin

*

No

rflo

xaci

n

PB

DE

183

MB

T

DB

T

23

78-T

CD

F*

12

346

78-

Hp

CD

D

MC

CP

*

MD

2M

MD

3M

PB

DE

209

OC

DD

12

346

78-

Hp

CD

F

OC

DF

MD

M

PB

DE

154

Co

ba

lt

year

6. TIME-TREND ANALYSIS

54

The levels of the FQs norfloxacin (Figure 16a) and ciprofloxacin in sludge

(2004-2010) decreased annually by 60% and 20%, respectively, correlating

well with declines in national prescriptions of these antibiotics of ca. 90% and

20%, respectively (Swedish MPA, 2011). Triclosan, which is frequently used as

an antibacterial agent in personal care products, has gained public attention

due to its negative environmental impact (Crofton et al., 2007; Veldhoen et al.,

2006), which should also lead to reductions in its sludge levels. The national

use of triclosan declined during the studied years by about 30% and this was

reflected in an annual 65% decline of the triclosan concentration in the sludge

(Figure 16b).

However, increases in levels of about 30% per year were detected for the linear

methylsiloxanes, in line with the national use of siloxanes more than doubling

during these years. Figure 16c shows the time-trend of decamethyl-

tetrasiloxane (MD2M) levels.

The OTCs MBT (Figure 16d) and DBT, the PFCs perfluorododecane acid

(PFDoDA) and perfluorooctane sulfonamide (PFOSA), the PBDEs 99, 154

(Figure 16e) and 183, 1,2,4-trichlorobenzene (124CBz, Figure 16g) and highly

chlorinated PCDD/Fs (OCDD, Figure 16h) all exhibit a significant downward

trend over time. Due to the limitations of the product register for these

compounds, i.e. its failure to track amounts present in imported goods, their

levels in sewage have not been compared with the quantities used annually.

6. TIME-TREND ANALYSIS

55

Figure 16. Significant detected time-trends in levels of the monitored sludge contaminants (2004-2010), a) Norfloxacin; b) Triclosan; c) MD2M, Decamethyltetrasiloxane; d) MBT, Monobutyltin; e) PBDE 154; f) PBDE 209; g) 124CBz, 1,2,4-trichlorobenzene; and h) OCDD, Octachlorodibenzo-p-dioxin. From Paper IV.

c) MD2M

0

25

50

75

100

125

150

175

05 07 09

a) Norfloxacin

0

1000

2000

3000

4000

5000

6000

05 07 09

b) Triclosan

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

05 07 09

d) MBT

0

50

100

150

200

250

300

05 07 09

e) PBDE 154

0

1

2

3

4

5

05 07 09

f) PBDE 209

0

100

200

300

400

500

600

700

05 07 09

g) 124CBz

0

50

100

150

200

05 07 09

h) OCDD

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

05 07 09

Year

Co

nc

. µ

g k

g-1

d.w

.

6. TIME-TREND ANALYSIS

56

However, both highly chlorinated PCDD/Fs and 124CBz are listed in the

Stockholm Convention (UNEP, 2001) and the WFD (EU, 2000), hence their

decreasing trends may be associated with restrictions in their use. PBDEs 99,

154 and 183 have also been classified as POPs under the Stockholm Convention

(since 2009) and, PBDEs 99 and 154 are WFD priority substances. This

classification may have indirectly influenced their downward trends, or

enhance their decline in coming years. Since the global phase-out of PBDEs 154

and 183 (pentaBDE and octaBDE) as flame retardants in plastics they have

been replaced by PBDE 209 (decaBDE), hence unsurprisingly levels of decaBDE

have annually increased by 16%.

However, although use of PBDE 209 (Figure 16f), regulated in the RoHS

directive (EU, 2003), has dropped in national usage by 83% (2004-2008) there

is no clear downward trend in its levels in sludge yet. Medium chain

chlorinated paraffins (MCCP) show the same pattern, with an annual increase

of 13% in sludge levels, but halving of the amount used over the years. The

unexpected uptrends of these flame retardants (PBDE 209 and MCCP) are

probably due to considerable amounts entering the country as additives in

imported goods (textiles, plastics, computers and other electronic goods) that

are not recorded in the product register. A further probable contributory factor

is that many articles treated with flame retardants have long lifetime and large

stocks.

Significant time-trends in sludge levels of the OPs tris(1,3-dichloro-2-propyl)

phosphate (TDCPP) and tris(2-butoxyethyl) phosphate (TBEP), also used as

flame retardants (and plasticizers), only appeared when suspected outliers

were included in the analysis. However, it will be interesting to follow up these

compounds in the future, due to their potential use as substitutes for PBDEs

and the plasticizer DEHP, respectively, when more data are available and hence

the statistical power has increased.

Sludge contaminants with constant levels

Evaluation of the sludge contaminants for which no significant time-trends

were detected is also interesting for assessing whether (legal) regulatory

actions have been effective to date. DEHP, used in the PVC industry, was

classified as a WFD priority substance more than a decade ago (EU, 2000), and

has subsequently been more strictly regulated (EU, 2005). However, although it

has mainly been substituted by DINP since early 2000 (Petersson Lars, 2004;

6. TIME-TREND ANALYSIS

57

Swedish Chemicals Agency, 2007) and the annual quantity used in Sweden

declined by about 40% from 2004 to 2009, no clearly significant time-trend is

apparent in its sludge concentrations as yet (nor for DINP). The constant levels

(mg kg-1 d.w.) of DEHP over the years may be due to the large amounts

remaining in the technosphere and consequent time-lag before concentrations

probably decline in the sewage sludge. In this context it is worth noting that

vinyl flooring has an average lifetime of 20 years. On the other hand, an

indication (albeit not statistically significant) of an increasing trend in DINP

levels can be discerned, the annual median concentration (based on data from

the studied STPs) of DINP in sludge increased by 50% from 2004 to 2010 while

the recorded quantities of DINP increased by about 90% from 2000. Additional

annual measurements are required before significant time-trends can be seen

and hence evaluate if the substitution of DEHP by DINP (in the PVC industry;

DEHP is still used in medical devices) has been successful.

Reported levels of PFOS have been relatively constant in sewage sludge during

the last decade (Clarke and Smith, 2011), despite a manufacturers’ voluntary

phase-out in early 2000. Since 2009, PFOS has been regulated by the Stockholm

Convention (UNEP, 2001), which may affect its future levels in sewage sludge.

However, mass flow studies have shown that degradation of other PFCs to

PFOS may occur during sewage treatment (Bossi et al., 2008; Loganathan et al.,

2007), thus STPs may still continue to release significant amounts of PFOS into

the environment. During the seven study years, the concentrations of PFOS in

the sludge remained quite constant (µg kg-1 d.w.), but are likely to decline in the

future due to the stricter regulations. If no declining trend is observed in the

coming years other PFCs may also need to be more strictly regulated to ensure

that no formation of PFOS occurs through other PFCs.

Levels of the seven monitored metals (except cobalt) also remained constant

(mg kg-1 d.w.) within the investigated time interval and were exclusively

detected below their national limit levels, for materials intended for

agricultural uses (Cd, 2; Cr, 100; Cu, 600; Hg, 2.5; Ni, 50; Pb, 100; Zn, 800 mg kg-

1 d.w.; Ministry of the Environment, 1998). However, median concentrations of

cadmium in the sludge seem to have decreased substantially, by ca. 30% per

year, possibly partly because certified STPs are obliged to limit cadmium to

phosphorus ratios in sludge to 17 mg Cd per kg P (SWWA, 2008) by 2025.

Future regression analyses will reveal if these actions lead to statistically

significant decreases in sludge concentrations.

6. TIME-TREND ANALYSIS

58

Action limits

In Sweden a number of Environmental Objectives jointly encapsulate the

official long-term environmental vision. One, “A Non-Toxic Environment”,

states that, within one generation, the concentrations of non-naturally

occurring substances in the environment will be close to zero and their impacts

on ecosystems will be negligible. In Sweden, and other countries, the work to

reduce emissions upstream STPs are important for minimizing levels of

hazardous substances in the sewage and fulfilling legal environmental

requirements.

“Action limits” are necessary to facilitate identification, and implementation, of

required enhancements, and since no formal limits are currently available we

calculated the 90th percentile (based on the sludge contamination

concentrations in the nine STPs monitored in 2010) for all compounds included

in Figure 15. These action levels can be continuously updated using data

acquired from the annual environmental sludge monitoring program. The

purpose of the limits is to provide professionals with tools to identify

compounds whose concentrations greatly exceed typical levels (in this case for

Swedish sludge). They can then decide if further actions are needed, e.g. to

restrict the emissions from point sources or inform the public about alternative

ways to dispose of harmful substances (rather than flushing them down the

drain).

Systematic elimination and reduction, e.g. by using these calculated “action

limits”, of the largest contributions of contaminants to the sewage sludge will

improve the quality of the sludge. Ideally, such a systematic approach could

lead to sufficient reductions in levels of contaminants in the sludge for both

authorities and the public to accept application of the sludge to agricultural

soils. This would be a big step towards sustainable management of nutrients.

To conclude, significant time trends in sludge levels were detected for

remarkably high proportions (a third) of the compounds examined in this

analysis. The trends for many of the sludge contaminants that showed

significant trends with time followed trends in the quantities used in Sweden,

generally decreasing due to increasingly strict environmental legislation and

regulations. Most of the significant trends were reductions with time, but about

a quarter were increasing trends, and those of the linear methylsiloxanes

followed the same patterns of increase as in the national use quantities.

6. TIME-TREND ANALYSIS

59

However, levels in sewage sludge of various contaminants that have been

substituted and legally restricted showed no significant trends, or only slowly

declined several years later. Time-lags, due to large amounts of chemical

substances remaining in the technosphere, and limitations in the product

register for e.g. phthalates and PBDEs may explain the lack of expected trends.

In the future, when more data are available, it should be possible to judge

whether the substitution of PBDEs and PCAs by OPs or DEHP by DINP has been

effective (provided it is reflected in changes in the sewage sludge).

Regardless of future prospects, the results show that statistical time-trend

analyses can detect significant decreasing or increasing trends in levels of

chemical substances in sewage sludge. The time period applied could be

extended to at least ten years to confirm the significance of detected trends and

potentially detect time-trends for a larger set of compounds. Prolonging the

monitoring campaign and time-trend analysis is also required for evaluating

whether any discernible trends will appear for substances that have recently

been substituted by others that are (hopefully) less toxic to humans and the

environment.

60

61

-

In a previous study, at a French STP (Semard et al., 2008), the feasibility of

using GCxGC-TOFMS for broadly screening hazardous substances in urban

sewage water was investigated. However, the cited study focused on specific

compound groups, especially PPCPs, pesticides and CMRs. The authors

concluded that most of these compounds were removed efficiently by current

STP technology, but that more studies are needed to validate the removal

efficiency of GCxGC-amenable compounds. Therefore, in study V (Paper V), a

broad and unbiased characterization (non-targeted screening) of sewage water

(influent and effluent, in Umeå STP) was performed using comprehensive

GCxGC-TOFMS. The water samples were subjected to minimal preparation

(non-discriminating extraction and clean-up), in order to retain as much

information as possible about their chemical composition, before the

instrumental analysis. The results were then interpreted with the aim to

evaluate the STP removal efficiency (in Chapter 4 general calculations are

described) of structurally diverse organic sewage contaminants, especially

those that were poorly removed. Details of the experimental protocols (sample

treatment and instrumental analysis) and data evaluation are given in Paper V.

An introduction to the GCxGC technique is presented in Chapter 4. In GCxGC

analytes are initially separated on two GC columns, with distinctly different

separation modes (“dimensions”). In this study a non-polar column followed by

a semi-polar/highly polarizable column were used for the first (1D) and second

(2D) dimensions, respectively, which thus primarily separated the compounds

according to their volatility, and polarity or polarizability, respectively.

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

62

Principal Component Analysis

The results from the PCA, the multivariate analysis technique used for

visualizing patterns in the data and detecting outliers, show distinct grouping

of the replicates of sample matrices (five replicates per sample matrix) and the

four blank samples (one for each sample matrix). Further information

regarding the PCA technique can be found in Chapter 4. As can be seen in

Figure 17, the sample matrices (influent aqueous, effluent aqueous, influent

particles, effluent particles and blank samples) clearly separated from each

other and no suspected outliers were detected.

The first principal component (PC1) reflects differences in concentration,

samples and compounds with the highest concentrations appearing to the left,

whereas the second principal component (PC2) largely reflects differences in

contaminant patterns between aqueous and solid samples. Blank samples have

low concentrations of analytes and a profile that matches those of neither

aqueous nor particle samples, hence they are positioned far to the right along

PC1 and close to the middle of PC2. The loading plot (Figure 17, lower)

illustrates underlying reasons for the patterns in the score plot (Figure x,

upper) and reflects the physicochemical properties of the contaminants, with

compounds having high water solubility, e.g. caffeine and TCEP in the lower

right quadrant. Compounds in the lower right quadrant are likely to have low

removal efficiencies during sewage treatment. In the upper half of the loading

plot non-polar compounds are found, which are expected to sorb to sludge and

hence, have high removal efficiencies.

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

63

Figure 17. Principal Component Analysis (PCA) plots of the data, 1128 observations (compounds) and 24 variables (sample matrices, i.e. five replicates of each sample matrix and four blank samples). The first and second principal components (PC1 and PC2) explain 41% and 25%, respectively, of the total variance in the data. The score plot, upper, shows the relationships among the samples, with distinct groupings of the sample matrices. The loading plot, lower, shows the corresponding relationship among the compounds. TCEP, Tris(2-chloroethyl) phosphate. From Paper V.

-0.1

0.0

0.1

0.2

0.3

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28

PC2

PC1

InAq 1InAq 2

InAq 3

InAq 4InAq 5

InAq Blank

InPart 1

InPart 2InPart 3

InPart 4

InPart 5

InPart Bl

OutAq 1

OutAq 2

OutAq 3

OutAq 4

OutAq 5

OutAq Bl

OutPart 1

OutPart 2

OutPart 3OutPart 4

OutPart 5

OutPart Bl

-8

-6

-4

-2

0

2

4

6

8

-8 -6 -4 -2 0 2 4 6 8 10 12 14

PC2

PC1

Influent particles

Effluent particles

Influent/Effluentaqueous

Blank samples

TCEP

Caffeine

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

64

Assessment of the STP’s removal efficiency

This study showed that the STP’s overall removal efficiency of GCxGC-amenable

compounds is relatively good, exceeding 70% for most of the 1128

contaminants detected (Figure 18). This non-targeted screening also showed

that the removal efficiencies are correlated both to the first dimension (1D) and

second dimension (2D) retention times of the sewage contaminants. As

expected, compounds with low polarity (low water solubility and strong

affinity to sludge; the compounds with short 2D retention times in Figure 18b,)

were efficiently separated. It is harder to explain the correlation of removal

efficiencies with 1D retention times, because during the biological treatment in

STPs, for instance, volatile compounds may be lost through evaporation, hence

efficient removal would be expected for compounds with short 1D retention

times. In contrast, the opposite relationship was observed, i.e. the

volatilities/2D retention times of the compounds were inversely related to their

removal efficiency. However, the 1D retention times are also related to the

lipophilicity of the contaminants; GCxGC-amenable compounds are generally

semi-volatile and contain at most small numbers of polar functional groups.

Further, the lipophilicity (and 1D retention times) of the sewage contaminants

is strongly, positively correlated with their molecular weight and tendency to

sorb to sludge. In contrast, compounds with higher proportions of polar

functional groups are either not extracted by dichloromethane (the extraction

solvent used) or degraded in the GC inlet.

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

65

Figure 18. The removal efficiency (%) of sewage contaminants vs. a) volatility (1D), and b)

polarity (2D). The removal efficiencies represent mean values over 2 minutes (

1D) and 0.1 s

(2D), respectively. From Paper V.

2D graphs (bubble plots) were constructed to illustrate the influence of various

physicochemical characteristics of the compounds on the STP treatment

efficiency. These new plots were created because, as mentioned above, single-

dimensional representation (or separation) does not provide sufficient

resolution. These 2D graphs, in which the position of the compounds shows

their retention time and the size of the markers indicates their removal

0

10

20

30

40

50

60

70

80

90

100

10 14 18 22 26 30 34 38 42 46 50 54 58 62 66

Rem

oval

Eff

icie

ncy

(%)

Volatility 1D (minutes)

0

10

20

30

40

50

60

70

80

90

100

0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9

Rem

oval

Eff

icie

ncy

(%)

Polarity 2D (seconds)

a)

b)

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

66

efficiency, can be seen in Figure 20. Volatile organic compounds (VOCs) have

boiling points below 250°C, according to the EU´s definition (EU, 2004), which

corresponds to about 900 s, or a quarter of the total retention time in 1D. To

summarize the information displayed in the bubble plots; volatile non-polar

compounds appear in the lower left corner, volatile polar compounds in the

upper left, semi-volatile non-polar compounds in the lower right, and semi-

volatile polar compound in the upper right (as schematically shown in Figure

19). However, 2D chromatography occurs under isothermal conditions and the

polar compounds are therefore spread out over a larger area than the non-

polar.

Volatile

Polar

Semi-volatile

Polar

Volatile

Non-polar

Semi-volatile

Non-polar

Figure 19. Schematic representation of positions of contaminants according to their volatility and polarity in the bubble plots (Figure 20).

Data for the total set of 1128 compounds (Figure 20a), clearly show that highly

volatile (far left) and non-polar compounds (lower parts) are removed to a high

degree (as expected) during the sewage treatment process.

In order to find and identify the compounds that are poorly removed by current

STP treatment technology, the compounds with removal efficiencies higher

than 65% were excluded from further analysis. The average removal efficiency

of the groups of efficiently and poorly removed sewage contaminants (thus

defined) was 94% and 22%, respectively. Then a new bubble plot was created

(Figure 20b), that was much less complex and easier to interpret. In this new

plot, the sizes of the bubbles represent the “breakthroughs” in the STP, i.e. the

fractions of the respective sewage contaminants that were not removed. It

indicated that many strongly retained (highly polar or polarizable) compounds

in 2D are poorly removed, i.e. they have large STP breakthroughs. For weakly

retained, lipophilic, compounds that elute at 2D retention times shorter than 0.5

s, higher removal efficiencies are observed, as can also be seen in Figure 18b.

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

67

Figure 20. Bubble-plots representing a) the removal efficiency (%) of the total data set of 1128 compounds; b) the breakthrough (%) of the same compounds; and c) the breakthrough (%) of the ca. 200 compounds that had a removal efficiency less than 65%. From Paper V.

0.0

0.5

1.0

1.5

2.0

0 500 1000 1500 2000 2500 3000 3500 4000

Volatility 1D (seconds)

Pola

rity

2D (

seco

nds)

0.0

0.5

1.0

1.5

2.0

Pola

rity

2D (

seco

nds)

0.0

0.5

1.0

1.5

2.0Po

lari

ty2D

(se

con

ds)

a)

b)

c)

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

68

Tentative identification of poorly removed contaminants

A total of 68 compounds were tentatively identified (among the 188

components that had less than 65% removal efficiency) using the NIST library.

The final data set is given in Table 2 in Paper V. An additional bubble plot was

created for this set of compounds, Figure 20c. Effluent concentrations of these

compounds varied between 0.2 and 12 000 ng L-1, 90% of them were found to

be predominantly (>90%) dissolved in the aqueous phase of the effluent, and

60% of them were predominantly dissolved in the aqueous phase of the

influent. These findings were also reflected in the lower removal efficiencies

estimated for these water soluble compounds and most of the tentatively

identified compounds had less than 50% removal efficiency. An interesting

observation was that although 1H-Indole-3-carboxaldehyde was exclusively

attached to particles in both influent and effluent, it was still not efficiently

removed. The presence of 1H-Indole-3-carboxaldehyde in the influent and lack

of its removal may be due to its formation, e.g. from indole, during the

treatment process. Many of the tentatively identified compounds have polar

functional groups (Table 2 in Paper V) that increase their water solubility and

make them more prone to follow the water path through the STP. In addition,

several of the compounds share some common structural features, as

illustrated in Figure 21, which presents the percentage of sewage contaminants

that possess certain functional groups, e.g. 10% of the compounds were

(halogenated) organophosphate esters, structural features that make these

compounds relatively stable and resistant to degradation.

The two amides, carbamazepine (pharmaceutical) and diethyltoluamide (DEET,

insect repellent), were completely dissolved in the aqueous phase (both

influent and effluent) and were not removed at all. The poor removal of

carbamazepine during sewage treatment is consistent with a previous mass

balance study by Nakada et al. (2010) who also concluded that DEET removal

was limited. Notably, carbamazepine concentration was twice as high in the

effluent as in the influent, again in agreement with previous studies (Jelic et al.,

2011; Kim et al., 2007). Thus, in this case too, some formation appears to occur,

e.g. via deconjugation. OPs are a group of compounds that were frequently

detected and insufficiently removed, with a maximum removal efficiency of

33%. Two of the OPs, TBEP and TCEP, were almost completely dissolved in

influent and effluent water (>94%). These findings are also consistent with

reports by Marklund et al. (2005) of at most marginal removal of TBEP and

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

69

halogenated OPs (TCEP, TCPP and TDCPP) in Swedish STPs with a maximum

(average) removal of 28% for TDCPP.

Figure 21. Percentages of tentatively identified sewage contaminants that share the indicated functional groups and moieties.

Effluent concentrations and sources of poorly removed contaminants

The total effluent (aqueous and particle) concentrations of the 68 tentatively

identified sewage contaminants were calculated (Table 2 in Paper V) to obtain

an overview of their environmental loads from the STP. Effluent concentrations

of selected compounds and the most abundant sources for the tentatively

identified sewage contaminants are given in Figures 22 and 23, respectively.

Large proportions of traffic-related compounds were identified, largely

representing derivative (ketones and quinones) of PAHs and other polycyclic

aromatic compounds. Emissions from vehicles and other combustion sources

are likely sources of these compounds in sewer systems. The most abundant

compound (at levels of 12 µg L-1) was 2,4,7,9-tetramethyl-5-decyn-4,7-diol,

which is used as a defoamer in paint, e.g. for vehicles. Other potentially traffic-

related compounds include the benzothiazoles (used in the rubber industry),

which were the fourth most abundant of the compounds (at 2.2 µg L-1).

68

53

31

1916

10 107

3 3 1.50

10

20

30

40

50

60

70

80

Aro

mat

ic

Ke

to/e

ster

S,N

,O-h

ete

rocy

clic

Aro

mat

ic a

nd

(h

ete

ro)c

yclic

(He

tero

)cyc

lic

(Ha

loge

nat

ed)

org

ano

ph

osp

hat

e e

ste

rs

S/O

-eth

ers

Am

ide

s

Nit

ro

Aci

ds

Am

ine

%

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

70

Besides traffic-related compounds, large proportions of flame retardants and

plasticizers, food additives and PPCPs were also identified as poorly removed

sewage contaminants (see Figure 23). Among the PPCPs, a large proportion

was additives in cosmetics, e.g. odoriferous substances used as fragrances in

perfumes. The PPCPs found at the highest levels was the UV-blockers

benzophenone and oxybenzone (930 and 230 ng L-1, respectively). Two anti-

corrosive agents that are frequently used as additives in dishwasher tablets

were also detected (at a total concentration of 73 ng L-1) and were completely

dissolved in the aqueous phase of both influent and effluent water.

Figure 22. Effluent concentrations of selected tentatively identified sewage contaminants.

These findings of substances such as PPCPs and dishwasher tablet additives are

directly related to the intended uses of consumer products, and a direct

correlation can be seen between their use and STP effluent levels. Some

plasticizers and flame retardants, namely benzenesulfonamides (detected at 5.5

µg L-1) and the OPs (TBEP, 3.6 and TCEP, 0.36 µg L-1), respectively, were found

in similar concentrations to the PPCPs and other chemicals that are

intentionally used and thus released to the sewer system. These kinds of

compounds are probably slowly emitted from the stock of consumer articles

and building materials in society.

12000

5500

3600

2200930 460 360 230 110 73 23 2.8

0

2000

4000

6000

8000

10000

12000

14000

2,4

,7,9

-Tet

ram

eth

yl-

5-d

ecyn

-4

,7-d

iol

Be

nze

nes

ulf

on

amid

e

TB

EP

Be

nzo

thia

zole

Be

nzo

ph

en

on

e

Caf

fein

e

TC

EP

Oxy

ben

zon

e

DE

ET

An

ti-c

orr

osi

ve a

gen

ts

Car

ba

ma

zep

ine

1H

-In

do

le-3

-car

bo

xald

eh

yde

ng

L -1

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

71

Figure 23. Sources (origins) of the indicated percentages of the tentatively identified sewage contaminants.

Traditional approaches for assessing STP treatment efficiency

Analyses of STPs’ removal efficiencies usually focus on selected compounds or

groups of compounds. When target compounds are selected at early stages of a

study in such a manner, much of the subsequent experimental work and

analytical instrumentation that should be used is essentially predetermined. In

addition, method development may have been implemented, all of which limits

the scope for identifying both “new” potential compounds that are poorly

removed during sewage treatment and emerging pollutants. Benefits of such

approaches are that they can be optimized, thereby maximizing selectivity and

sensitivity. The drawbacks may be that these approaches discriminate against

many constituents of sewage, hence the results may give misleading overviews

of the overall environmental load derived from STPs and the ability to identify

poorly removed contaminants may be compromised. Thus, non-targeted

screening procedures, like the one developed in this study (Paper V), are

highly complementary to the traditional approaches.

To conclude, an environmetrics systematic approach was adopted and as

many as possible of the compounds that were poorly removed were tentatively

identified. This study demonstrates a new tool for identifying (GCxGC-

amenable) chemical substances that are not efficiently removed during current

sewage treatments. For non-polar and semi-polar compounds this

environmetrics approach seems to work satisfactorily. The results revealed

common structural features of the GCxGC amenable sewage contaminants for

22

16

1210

3

0

5

10

15

20

25

Tra

ffic

re

late

d

Fla

me

ret

ard

ants

and

pla

stic

izer

s

Foo

d a

dd

itiv

es

PP

CP

s

An

ti-c

orr

osi

veag

ents

%

7. NON-TARGETED SCREENING OF POORLY REMOVED CONTAMINANTS

72

which more effective treatment technologies need to be developed. In

comparison with traditional GC-MS methodologies this GCxGC approach

provides better chromatographic and mass spectrometric resolution. It also

provides comprehensive comparisons of influent and effluent concentrations,

and thus allows assessment of the STP removal efficiency of systematically

prioritized contaminants. Moreover, information on the tentatively identified

contaminants’ physicochemical properties, obtained from their 1D and 2D

retention times, can help assessments of their structures.

Although this study had limitations, notably the discrimination against polar

compounds (in extraction and instrumental analysis), it has provided new

knowledge that should facilitate the future development of STPs.

73

Conclusions

A number of conclusions have been drawn from the work underlying this

thesis. Firstly, the quality of the sewage sludge and the levels and distribution

patterns of the sludge contaminants, both within and between the STPs, seem

to remain quite constant over time. However, some minor variations were

observed using PCA (Paper III), notably high levels of PFCs appeared to be

related to textile industries and propiconazole to agricultural activities.

Nevertheless, the overall findings indicate that the levels of contaminants in

sewage sludge seem to be largely independent of the location, size and

treatment techniques applied at the STPs, and generally, of the types of human

activity connected to them. The total and relative concentrations of the sludge

contaminants were found to be fairly constant on a d.w. basis, with some

exceptions, indicating that the pollutants originate from broad usage and

diffuse dispersion rather than (industrial) point sources. Overall, of the

considered substances, metals and PCDD/Fs make the highest and lowest

contributions, respectively, to the environmental loads associated with sewage

sludge. The acquired data on levels, profiles and variations in sludge

contaminants (sludge quality), in studies III and IV (Papers III and IV) and

others extend both the available information and understanding of the degree

and nature of sludge contamination, which should help attempts to monitor

changes in its contaminants and revisions, if necessary, of limit values.

Secondly, significant time-trends in levels of a-third of the sludge contaminants

included in the national environmental monitoring program were detected

over a period of seven years (Paper IV). These contaminants include

representatives of almost all groups of investigated compounds. Thus, the

initial selection of compounds for inclusion in the sludge monitoring program

(focusing on chemicals that should have declined in environmental

compartments following restrictions on their use due to their adverse

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

74

environmental effects) appears to have been successful. The levels of

compounds displaying significant time-trends generally decreased, due to

regulatory actions, following declines in the quantities used nationally.

However, a quarter of these compounds showed increasing trends (also in line

with use statistics).

It was also concluded, from results presented in Paper IV, that it will be

possible to tell if the substitution of brominated flame retardants, e.g. by

phosphorus-based flame retardants, is reflected in sewage sludge

concentrations in the future. Moreover, international and national

environmental legislation and regulations seem to be effective tools for

reducing releases of selected hazardous compounds into the environment, with

the possible exception of PBDE 209, which was regulated in the RoHS directive

in 2003 (EU, 2003), but its levels in sewage have not yet decreased. Increased

public awareness also seems to be important for environmental sustainability.

For example, levels of triclosan in both sludge and personal care products have

declined, although it is not regulated, probably because its toxicity to aquatic

organisms has been frequently highlighted in the media. Nevertheless, it is also

important to have powerful tools for assessing the effectiveness of measures

taken to reduce fluxes of chemicals from the technosphere to the environment.

Indications of the utility of retrospective temporal trend analyses of sludge

contaminant concentrations for this purpose were also obtained and presented

in Paper IV.

Thirdly, the STP removal efficiency of anthropogenic substances in Sweden is

generally good. However, results presented in Paper II indicate that STPs, at

least those in cold climates, do not efficiently remove certain polar

contaminants, and the temperature also seems to influence the distribution of

antibiotics between water and particulate matter (Paper I). Important tools for

predicting the behaviour and fate of anthropogenic substances after reaching

an STP are STP fate models, provided of course that their partitioning

coefficients and other parameters are sufficiently accurate. Therefore, the

validity of a fate model was assessed, and was found to provide poor

predictions of the proportions of polar compounds that partition to sewage

sludge (Paper II), hence fate models require improvement. In addition, despite

the relatively high removal efficiencies of the sludge contaminants observed in

study II, STPs remain potential sources of hazardous substances that may affect

organisms in aquatic and/or terrestrial environments. Thus, the treatment

process and plant design should be continuously refined to maximize the

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

75

removal of undesirable substances from the sewage and thus minimize their

release into the environment.

In the last study (Paper V) a non-targeted screening (by use of environmetrics

and GCxGC-TOFMS) was performed and found to fulfil the objective to assess

the STP removal efficiency, with emphasis to systematically analyse which

compound classes that are not efficiently removed using the current STP

technology. Although the attempt was to perform a non-discriminating

screening, this environmetrics systematic approach has limitations in the

assessment of STP removal efficiency of polar compounds. The polar

compounds are discriminated in the extraction (by the use of dichloromethane

as extraction solvent) and in the instrumental analysis (by the use of GC).

Nevertheless, these results improve the knowledge base for the development of

future STP technologies.

Future aspects

The compounds considered in Paper IV are included in the on-going annual

Swedish environmental (sludge) monitoring program. Most of the compounds

monitored in sludge are now also being analysed in effluent water (since 2010).

At the same time, the following compounds were also included in the program:

alkylphenols, used in detergents; bisphenol A, used in food and drink

packaging; musk compounds, used in fragrances; and NSAIDs. In a few years

the data acquired in these annual measurements may be subjected to time-

trend analysis in the same manner as for the sludge (see Paper IV). However,

the long-term goal for this part of the program is to be able to detect changes in

total inputs of chemicals (via effluent and sewage sludge) from STPs into the

environment using estimates acquired from time-trend analysis of comparable

samples. This may improve knowledge of anthropogenic environmental

impacts via STPs, and understanding of the most effective actions for achieving

national environmental objectives and a greener world, today and in the future.

Revision of legislation and regulations, development of appropriate channels

for providing preventive information to the public, and use of government

grants to promote improvements in sewage treatment technologies may be

some measures that should be prioritized.

However, in order to increase sludge recycling and the public’s acceptance of

products grown on sludge-amended soil it is of utmost importance to identify

key sludge contaminants, assess their potential human and environmental

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

76

risks, and take appropriate technical and/or regulatory actions to reduce the

emissions of pollutants that may pose a significant risk.

Since the untargeted assessment of STP removal efficiency focused on non- and

semi-polar compounds (Paper V), a complementary study focused on the polar

and non-biodegradable compounds should be performed using the same

approach. In such a study alternative extraction procedures (e.g. SPE

techniques capable of extracting highly polar compounds) and derivatisation

prior to GCxGC analysis or comprehensive LC should be applied. Finally, a fast,

high-resolution detection system would be required (e.g. high-resolution

TOFMS), providing accurate mass information to facilitate fast, accurate and

reliable identification of detected analytes.

Improvements of STPs

Both upstream measures and continuous refinements of treatment processes

are important to improve the sludge quality and reduce future environmental

impact on our lakes, rivers and coastal areas. In Sweden, since 2002 it has been

possible to certify the STPs (SWWA, 2008) in terms of their ability, for instance,

to meet national environmental goals for recycling phosphorus from sewage to

agricultural land (Swedish EPA, 2002). Currently 33 Swedish STPs are certified

(SP, 2011) and a further dozen have applied for certification. The aims of this

certification system are: to ensure that the nutrients from the sewage are

retained responsibly, and that all the health and safety requirements are met;

to make information about sludge production and its composition public; and

to provide a catalyst for further improvement of the raw sewage quality and

thus sludge quality.

Liming sludge has, for instance, prove to be an effective way to ensure that no

infections are spread, i.e. the liming kills germs. This treatment of sludge and

pasteurization are approved sanitation methods that allow the sludge to be

used as fertilizer in agriculture. Application of a thermophilic hydrolysis pre-

step to the anaerobic mesophilic digestion is currently under evaluation in

Sweden as a new sanitation approach (NSVA, 2011b) that may provide an

attractive alternative to pasteurization, with the possible potential to generate

more biogas.

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

77

However, through the enormous flow of chemical substances that circulate in

the technosphere today, many undesirable (hazardous) compounds will reach

the sewer systems. Amounts of PPCPs, surfactants, industrial additives, EDCs

and numerous other compounds, e.g. alkylphenols, antibiotics, bisphenol A,

musk compounds, pesticides, phthalates, parabens (preservatives) and

steroidal estrogens used in modern society today are increasing. PPCPs and

EDCs are micro-contaminants (not currently regulated), which require

advanced STP technology for removal and thus elimination of the potential

threats they pose to aquatic organisms and human health. The current

technology of conventional STPs is not designed to remove emerging and new

contaminants. Their initial purpose was to remove nutrients and BOD and they

efficiently remove non-polar compounds, but not necessarily others. Therefore,

there is a need for alternative treatment steps in conventional STPs that are

capable of removing water soluble contaminants, but this is challenging due to

the wide range of physicochemical properties of these emerging and new

compounds.

Alternative treatment steps

Advanced techniques, such as activated carbon or membrane-filtration based

separation, oxidation (by ozonation, O3, chlorination, or ultraviolet light in

combination with hydrogen peroxide, UV/H2O2) have been discussed as

additional treatment steps globally. The separation techniques are not

destructive methods and the compounds are either separated by adsorption or

semi-permeable membranes and high differential pressures, while the

oxidative methods totally (or partly) break down or convert the compounds.

Such treatment processes have not yet been implemented in most conventional

STPs, but they all have specific benefits and limitations for removing trace

contaminants.

Powder activated carbon (PAC), treatments show promising potential for

dealing with many EDCs (Westerhoff et al., 2005), providing >90% removal

efficiencies with a 5 mg L-1 dose of PAC and 4 hour contact time. PAC also seems

to work better for hydrophobic compounds (log Kow > 5) than for polar

compounds. Granular activated carbon (GAC) has similar efficacy (Kim et al.,

2007) but is preferable (although its lower surface-area-to-volume ratio than

PAC) because it facilitates subsequent work as it can be destroyed (combusted

with energy recovery) or regenerated and will not end up in the sludge, unlike

the powdered form. Other promising techniques are membrane filtration

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

78

methods, such as nanofiltration (NF; pore size, ~1 nm) and reverse osmosis

(RO; pore size, ~0.1 nm), although concentrates generated by these filtration

methods must be further processed, e.g. by ozonation. Kim et al. (2007) found

that NF and RO provided excellent removal of several PPCPs and TCEP (> 95%

for all those tested). They also suggested using GAC and membrane filtration

(NF or RO) for efficient removal of micro-contaminants. In practice, NF may be

preferable due to the higher pressure (higher energy) required for RO and the

higher amounts of salts that are separated, but both GAC separation and NF

seem to be interesting processes that are capable of removing micro-

contaminants such as PPCPs and EDCs.

Oxidation processes, such as ozonation and chlorination, remove reactive

compounds containing aromatic structures with hydroxide functional groups

(removal efficiencies > 90%, slightly higher for ozonation; Westerhoff et al.,

2005). Huber et al. (2005) concluded that an O3 dosage of 5 mg L-1 is sufficient,

but higher dosage may be needed when suspended solid concentrations are

high, with consequent increases in energy consumption. One benefit of

ozonation, besides removal of contaminants, is that the effluent water will be

disinfected. Removal can also be enhanced slightly by adding hydrogen

peroxide during ozonation (O3/H2O2).

To be able to oxidize (remove) as many contaminants as possible, to CO2 and

H2O, the amount of O3, the water temperature and the pH must all be optimized.

Unfortunately, high amounts of O3 would be required at the typical

temperatures (10-20 °C) and pH (ca. 7) of sewage in Swedish STPs. However,

chlorination processes should be avoided due to their production of chlorine

by-product (Buth et al., 2011), which reacts with EDCs, and although UV

processes provide high removal of PPCPs and EDCs, very high (and costly) UV

levels are needed (Adams et al., 2002). Using UV/H2O2 generates hydroxyl

radicals that are more effective oxidation agents (and more complex) than O3.

However, a critical factor with all these reactive techniques is the potential

production of toxic transformation products from sewage contaminants.

8. CONCLUDING REMARKS AND FUTURE PERSPECTIVES

79

To summarize, there are currently several alternative treatment steps that

could complement conventional STP processes to reduce levels of poorly

removed contaminants. It should be noted that in addition to improving

removal efficiencies of undesirable compounds in sewage, new techniques

should consume as little energy as possible, for direct financial and indirect

environmental reasons. If no formation of harmful by-products can be shown to

occur during ozonation this technique seems to be the most promising main

alternative, as it is also the most cost effective option.

A research project has been initiated recently in Sweden to evaluate various

technologies to reduce contaminants and pharmaceutical residues from

sewage, focusing largely ozonation and disc filtration (NSVA, 2011a). This study

is being carried out using a pilot-scale treatment plant, and since the target

compounds are not normally removed during conventional treatments the

additional treatment steps are applied at the end of the process.

It should though be interesting to evaluate if such a treatment step as ozonation

could be applied during the aeration before the biological process, in STPs that

have this process before the effluent exit. In such an implementation the

potential breakdown products by O3 may then be removed during the

biological treatment hence minimizing the release of undesirable (toxic)

compounds via the STP effluent into the environment. However, one drawback

may be the higher amount of O3 that may be required due to the higher content

of suspended materials (solids) during aeration than at the end of the process.

80

81

TACK till alla som på ett eller annat sätt har gjort denna resa möjlig. Speciellt

stort tack går till mina kära barn, ni är bara bäst och ni förgyller mitt liv i stort

som smått. Vad vore livet utan er kärlek? Jag älskar er och ni har alla en given

plats i mitt hjärta. Min hjärtevän, du har också en given plats i mitt hjärta och

med följande tre ord sammanfattar jag vad du betyder för mig – jag älskar dig!

Vilken tur att man har ett stort hjärta som gör att kärleken räcker till er alla.

TACK till mina handledare, ni har självklart varit värdefulla bollplank och ni

har på ett eller annat sätt bidragit till att denna bok nu äntligen är klar. Peter

Haglund, tack för att du trodde på mig! Du besitter en sådan enorm kunskap

inom en mängd områden (även utanför din expertis) som du har delat med dig

av under resans gång och som har givit mig ovärderlig kompetens inom

miljökemins underbara värld. Staffan Lundstedt, du tar dig verkligen tid att

besvara alla möjliga frågor och jag har aldrig tvekat att rådfråga dig när det har

uppstått funderingar. Jag lever efter devisen, ”det är bättre att ställa dumma

frågor än att göra dumma misstag”, vilket jag tror att ni vid det här laget känner

till.

TACK alla ni andra på ”miljökemi” (nya som gamla miljökemister) som jag har

haft nöjet att lära känna och arbeta med under alla dessa år. Ni har också på ert

alldeles speciella sätt mer eller mindre bidragit till att målet nu är nått. Ingen

nämnd och ingen glömd.

TACK till mina medförfattare, för intressanta diskussioner och ett gott

samarbete. Ni är alla guld värda.

TACK till all personal vid reningsverken, för er hjälpsamhet med provtagning

och delgivande av signifikant processinformation.

TACK till Naturvårdsverket, för finansiering och till Knut och Alice Wallenbergs

Stiftelse och COST Action 636, för ekonomiska bidrag till konferensresor.

TACK mor och far för att ni finns, och kom ihåg - kärleken övervinner allt.

TACK käre bror, för den tid vi fick tillsammans.

Ulrika Olofsson

82

83

Adams, C., Wang, Y., Loftin, K., and Meyer, M. (2002). Removal of antibiotics from surface and distilled water in conventional water treatment processes. Journal of Environmental Engineering-Asce 128(3), 253-260.

Bester, K. (2003). Triclosan in a sewage treatment process - balances and monitoring data. Water Research 37(16), 3891-3896.

Bossi, R., Strand, J., Sortkjaer, O., and Larsen, M. M. (2008). Perfluoroalkyl compounds in Danish wastewater treatment plants and aquatic environments. Environment International 34(4), 443-450.

Buth, J. M., Ross, M. R., McNeill, K., and Arnold, W. A. (2011). Removal and formation of chlorinated triclosan derivatives in wastewater treatment plants using chlorine and UV disinfection. Chemosphere 84(9), 1238-1243.

Buyuksonmez, F., and Sekeroglu, S. (2005). Presence of pharmaceuticals and personal care products (PPCPs) in biosolids and their degradation during composting. Journal of Residuals Science & Technology 2(1), 31-40.

CEC (2000). Working Document on Sludge, 3rd Draft. Council of the European Community, Brussels 27 April, 19 pp.

CEC (2011). Council of the European Community http://ec.europa.eu/environment/waste/sludge/index.htm.

Choi, K., Kim, Y., Park, J., Park, C. K., Kim, M., Kim, H. S., and Kim, P. (2008). Seasonal variations of several pharmaceutical residues in surface water and sewage treatment plants of Han River, Korea. Science of the Total Environment 405(1-3), 120-128.

Clarke, B., Porter, N., Symons, R., Blackbeard, J., Ades, P., and Marriott, P. (2008). Dioxin-like compounds in Australian sewage sludge - Review and national survey. Chemosphere 72(8), 1215-1228.

Clarke, B. O., Porter, N. A., Symons, R. K., Marriott, P. J., Stevenson, G. J., and Blackbeard, J. R. (2010). Investigating the distribution of polybrominated diphenyl ethers through an Australian wastewater treatment plant. Science of the Total Environment 408(7), 1604-1611.

Clarke, B. O., and Smith, S. R. (2011). Review of 'emerging' organic contaminants in biosolids and assessment of international research priorities for the agricultural use of biosolids. Environment International 37(1), 226-247.

Crofton, K. M., Paul, K. B., De Vito, M. J., and Hedge, J. M. (2007). Short-term in vivo exposure to the water contaminant triclosan: Evidence for disruption of thyroxine. Environmental Toxicology and Pharmacology 24(2), 194-197.

Dargnat, C., Teil, M. J., Chevreuil, M., and Blanchard, M. (2009). Phthalate removal throughout wastewater treatment plant Case study of Marne Aval station (France). Science of the Total Environment 407(4), 1235-1244.

84

Dewil, R., AppelS, L., and BaeyenS, J. (2006). Energy use of biogas hampered by the presence of siloxanes. Energy Conversion and Management 47(13-14), 1711-1722.

Dewil, R., AppelS, L., BaeyenS, J., Buczynska, A., and Vaeck, L. (2007). The analysis of volatile siloxanes in waste activated sludge. Talanta 74(1), 14-19.

EC (1990). EINECS, European inventory of existing commercial chemical substances. OJ C 146A.

EPI Suite™ (2007). The Estimation Program Interface (EPI) Suite. © 2000 U. S. EPA.

EU (1986). Directive 86/278/EEC. OJ L 181, 6-12.

EU (2000). The EU Water Framework Directive (2000/60/EC) - integrated river basin management for Europe.

EU (2003). Directive 2002/95/EC. OJ L 037, 19-23.

EU (2004). Directive 2004/42/CE. OJ L 143, 87-96.

EU (2005). Directive 2005/84/EC. OJ L 344, 40-43.

EU (2006). Regulation (EC) No 1907/2006. OJ L 396, 1-849.

EU (2008). Regulation (EC) No 1272/2008. OJ L 353, 1-1355.

Floda STP (2005). Miljörapport 2004 (in Swedish). Environmental Report.

Giger, W., Alder, A. C., Golet, E. M., Kohler, H. P. E., McArdell, C. S., Molnar, E., Siegrist, H., and Suter, M. J. F. (2003). Occurrence and fate of antibiotics as trace contaminants in wastewaters, sewage sludges, and surface waters. Chimia 57(9), 485-491.

Gobel, A., Thomsen, A., McArdell, C. S., Joss, A., and Giger, W. (2005). Occurrence and sorption behavior of sulfonamides, macrolides, and trimethoprim in activated sludge treatment. Environmental Science & Technology 39(11), 3981-3989.

Golet, E. M., Xifra, I., Siegrist, H., Alder, A. C., and Giger, W. (2003). Environmental exposure assessment of fluoroquinolone antibacterial agents from sewage to soil. Environmental Science & Technology 37(15), 3243-3249.

Gomez, M. J., Herrera, S., Sole, D., Garcia-Calvo, E., and Fernandez-Alba, A. R. (2011). Automatic Searching and Evaluation of Priority and Emerging Contaminants in Wastewater and River Water by Stir Bar Sorptive Extraction followed by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry. Analytical Chemistry 83(7), 2638-2647.

Haglund, P., and Olofsson, U. (2008). Miljöövervakning av slam, Redovisning av resultat från 2007 års provtagning (in Swedish). Swedish EPA.

Haglund, P., and Olofsson, U. (2011). Miljöövervakning av utgående vatten & slam från svenska avloppsreningsverk, Resultat från år 2010 och en sammanfattning av slamresultaten för åren 2004-2010 (in Swedish). Swedish EPA.

Haglund, P., and Olofsson, U. (2007). Miljöövervakning av slam, Redovisning av resultat från 2004, 2005 och 2006 års provtagningar (in Swedish). Swedish EPA.

85

Haglund, P., and Olofsson, U. (2010). Miljöövervakning av slam, Redovisning av resultat från 2009 års provtagning (inklusive en sammanfattning av åren 2004-2009) (in Swedish). Swedish EPA.

Haglund, P., and Olofsson, U. (2009). Miljöövervakning av slam, Redovisning av resultat från 2008 års provtagning (inklusive en sammanfattning av åren 2004-2008) (in Swedish). Swedish EPA.

Harrison, E. Z., Oakes, S. R., Hysell, M., and Hay, A. (2006). Organic chemicals in sewage sludges. Science of the Total Environment 367(2-3), 481-497.

Hedman, B., Burvall, J., Nilsson, C., and Marklund, S. (2007). PCDD/F in source-sorted waste fractions and emissions from their co-combustion with reed canary-grass. Waste Management 27(11), 1580-1592.

Hjortenkrans, D. S. T., Bergback, B. G., and Haggerud, A. V. (2007). Metal emissions from brake linings and tires: Case studies of Stockholm, Sweden 1995/1998 and 2005. Environmental Science & Technology 41(15), 5224-5230.

Holzel, C. S., Schwaiger, K., Harms, K., Kuchenhoff, H., Kunz, A., Meyer, K., Muller, C., and Bauer, J. (2010). Sewage sludge and liquid pig manure as possible sources of antibiotic resistant bacteria. Environmental Research 110(4), 318-326.

Huber, M. M., Gobel, A., Joss, A., Hermann, N., Loffler, D., McArdell, C. S., Ried, A., Siegrist, H., Ternes, T. A., and von Gunten, U. (2005). Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: A pilot study. Environmental Science & Technology 39(11), 4290-4299.

IVL (2005a). Results from the Swedish National Screening Programme 2004. Subreport 1: Adipates. IVL Swedish Environmental Research Institute Ltd. IVL Report B1645.

IVL (2005b). Results from the Swedish National Screening Programme 2004. Subreport 3: Limonene. IVL Swedish Environmental Research Institute Ltd. IVL Report B1647.

IVL (2005c). Results from the Swedish National Screening Programme 2004. Subreport 4: Siloxanes. IVL Swedish Environmental Research Institute Ltd. IVL Report B1643.

IVL (2006a). Results from the Swedish National Screening Programme 2005. Subreport 1: Antibiotics, Anti-inflammatory substances, and Hormones. IVL Swedish Environmental Research Institute Ltd. IVL Report B1689.

IVL (2006b). Results from the Swedish Screening 2005. Subreport 2. Biocides. IVL Swedish Environmental Research Institute Ltd. IVL Report 1700.

Jelic, A., Gros, M., Ginebreda, A., Cespedes-Sanchez, R., Ventura, F., Petrovic, M., and Barcelo, D. (2011). Occurrence, partition and removal of pharmaceuticals in sewage water and sludge during wastewater treatment. Water Research 45(3), 1165-1176.

86

Karrman, A., van Bavel, B., Jarnberg, U., Hardell, L., and Lindstrom, G. (2005). Development of a solid-phase extraction-HPLC/single quadrupole MS method for quantification of perfluorochemicals in whole blood. Analytical Chemistry 77(3), 864-870.

Katsoyiannis, A., and Samara, C. (2004). Persistent organic pollutants (POPS) in the sewage treatment plant of Thessaloniki, northern Greece: occurrence and removal. Water Research 38(11), 2685-2698.

Kim, S. D., Cho, J., Kim, I. S., Vanderford, B. J., and Snyder, S. A. (2007). Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters. Water Research 41(5), 1013-1021.

Kinney, C. A., Furlong, E. T., Zaugg, S. D., Burkhardt, M. R., Werner, S. L., Cahill, J. D., and Jorgensen, G. R. (2006). Survey of organic wastewater contaminants in biosolids destined for land application. Environmental Science & Technology 40(23), 7207-7215.

Kumar, S. J., Tesfalidet, S., Snell, J., and Frech, W. (2003). A simple method for synthesis of organotin species to investigate extraction procedures in sediments by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry - Part 1. Butyltin species. Journal of Analytical Atomic Spectrometry 18(7), 714-719.

Langdon, K. A., Warne, M. S., Smernik, R. J., Shareef, A., and Kookana, R. S. (2011). Selected personal care products and endocrine disruptors in biosolids: An Australia-wide survey. Science of the Total Environment 409(6), 1075-1081.

Law, R. J., Allchin, C. R., de Boer, J., Covaci, A., Herzke, D., Lepom, P., Morris, S., Tronczynski, J., and de Wit, C. A. (2006). Levels and trends of brominated flame retardants in the European environment. Chemosphere 64(2), 187-208.

Liang, D. W., Zhang, T., Fang, H. H. P., and He, J. Z. (2008). Phthalates biodegradation in the environment. Applied Microbiology and Biotechnology 80(2), 183-198.

Liljelind, P., Soderstrom, G., Hedman, B., Karlsson, S., Lundin, L., and Marklund, S. (2003). Method for multiresidue determination of halogenated aromatics and PAHs in combustion-related samples. Environmental Science & Technology 37(16), 3680-3686.

Lindberg, R., Jarnheimer, P. A., Olsen, B., Johansson, M., and Tysklind, M. (2004). Determination of antibiotic substances in hospital sewage water using solid phase extraction and liquid chromatography/mass spectrometry and group analogue internal standards. Chemosphere 57(10), 1479-1488.

Lindberg, R. H., Olofsson, U., Rendahl, P., Johansson, M. I., Tysklind, M., and Andersson, B. A. V. (2006). Behavior of fluoroquinolones and trimethoprim during mechanical, chemical, and active sludge treatment of sewage water and digestion of sludge. Environmental Science & Technology 40(3), 1042-1048.

Lindberg, R. H., Wennberg, P., Johansson, M. I., Tysklind, M., and Andersson, B. A. V. (2005). Screening of human antibiotic substances and determination of weekly mass flows in five sewage treatment plants in Sweden. Environmental Science & Technology 39(10), 3421-3429.

87

Loganathan, B. G., Sajwan, K. S., Sinclair, E., Kumar, K. S., and Kannan, K. (2007). Perfluoroalkyl sulfonates and perfluorocarboxylates in two wastewater treatment facilities in Kentucky and Georgia. Water Research 41(20), 4611-4620.

Marklund, A., Andersson, B., and Haglund, P. (2005). Organophosphorus flame retardants and plasticizers in Swedish sewage treatment plants. Environmental Science & Technology 39(19), 7423-7429.

Meyer, J., and Bester, K. (2004). Organophosphate flame retardants and plasticisers in wastewater treatment plants. Journal of Environmental Monitoring 6(7), 599-605.

Ministry of the Environment (1998). Förordning (1998:944) (in Swedish) (SFS 1998:808, 14 Kapitlet)). Miljöbalken (The Swedish Environmental Code).

Ministry of the Environment (2001). Förordning (2001:512) 10 § (in Swedish) (Ordinance (2001:512) on landfill of waste). Miljöbalken (The Swedish Environmental Code).

Nakada, N., Yasojima, M., Okayasu, Y., Komori, K., and Suzuki, Y. (2010). Mass balance analysis of triclosan, diethyltoluamide, crotamiton and carbamazepine in sewage treatment plants. Water Science and Technology 61(7), 1739-1747.

NRC (2002). Biosolids applied to land: advancing standards and practices, National Research Council. The National Academies Press, Washington DC, pp. 1-368.

NSVA (2011a). Forkningsprojekt för att reducera miljöfrämmande ämnen och läkemedelsrester i avloppsvatten. Nordvästra Skånes Vatten och Avlopp http://www.nsva.se/Var-verksamhet/Utvecklingsprojekt/NSVA-genomfor-forskningsprojekt-for-att-reducera-miljoframmande-amnen-och-lakemedelsrester-i-avloppsvatten/.

NSVA (2011b). Rötning med inledande termofilt hydrolyssteg för hygienisering (in Swedish). Nordvästra Skånes Vatten och Avlopp http://www.nsva.se/Var-verksamhet/Utvecklingsprojekt/NSVA-Hygienisering-av-slam/.

Peng, X. Z., Tang, C. M., Yu, Y. Y., Tan, J. H., Huang, Q. X., Wu, J. P., Chen, S. J., and Mai, B. X. (2009). Concentrations, transport, fate, and releases of polybrominated diphenyl ethers in sewage treatment plants in the Pearl River Delta, South China. Environment International 35(2), 303-309.

Petersson Lars (2004). Miljöredovisning 2003 (in Swedish) (Environmental Report 2003). Tarkett AB, Ronneby.

Reth, M., Zencak, Z., and Oehme, M. (2005). New quantification procedure for the analysis of chlorinated paraffins using electron capture negative ionization mass spectrometry. Journal of Chromatography A 1081(2), 225-231.

Richter, B. E., Jones, B. A., Ezzell, J. L., Porter, N. L., Avdalovic, N., and Pohl, C. (1996). Accelerated solvent extraction: A technique for sample preparation. Analytical Chemistry 68, 1033-1039.

88

Ricklund, N., Kierkegaard, A., and McLachlan, M. S. (2008). An international survey of decabromodiphenyl ethane (deBDethane) and decabromodiphenyl ether (decaBDE) in sewage sludge samples. Chemosphere 73(11), 1799-1804.

Roslev, P., Vorkamp, K., Aarup, J., Frederiksen, K., and Nielsen, P. H. (2007). Degradation of phthalate esters in an activated sludge wastewater treatment plant. Water Research 41(5), 969-976.

Rudel, H., Weinfurtner, K., and Koschorreck, J. (2010). Workshop of the German Environmental Specimen Bank on monitoring of priority pollutants and emerging substances in sewage sludge. Environmental Science and Pollution Research (Conference Report).

Saeger, V. W., Hicks, O., Kaley, R. G., Michael, P. R., Mieure, J. P., and Tucker, E. S. (1979). Environmental Fate of Selected Phosphate-Esters. Environmental Science & Technology 13(7), 840-844.

Schwarzenbach, R. P., Escher, B. I., Fenner, K., Hofstetter, T. B., Johnson, C. A., von Gunten, U., and Wehrli, B. (2006). The challenge of micropollutants in aquatic systems. Science 313(5790), 1072-1077.

Semard, G., Bruchet, A., and Cardinael, P. (2008). Use of comprehensive two-dimensional gas chromatography for the broad screening of hazardous contaminants in urban wastewaters. Water Science and Technology 57(12), 1983-1989.

Song, M., Chu, S. G., Letcher, R. J., and Seth, R. (2006). Fate, partitioning, and mass loading of polybrominated diphenyl ethers (PBDEs) during the treatment processing of municipal sewage. Environmental Science & Technology 40(20), 6241-6246.

SP (2011). Certificate of sewage sludge producers. SP Technical Research Institute of Sweden.

Spongberg, A. L., and Witter, J. D. (2008). Pharmaceutical compounds in the wastewater process stream in Northwest Ohio. Science of the Total Environment 397(1-3), 148-157.

Steen, I. (1998). Phosphorus Recovery - Phosphorus availability in the 21st century Management of a non-renewable resource. Phosphorus & Potassium(217).

Stevens, J. L., Northcott, G. L., Stern, G. A., Tomy, G. T., and Jones, K. C. (2003). PAHs, PCBs, PCNs, organochlorine pesticides, synthetic musks, and polychlorinated n-alkanes in UK sewage sludge: Survey results and implications. Environmental Science & Technology 37(3), 462-467.

STPs (2010). Miljörapporter 2009 (in Swedish). Environmental Reports.

Swedish Chemicals Agency (2006). Perfluorinated substances and their uses in Sweden, ISSN: 0284-1185. KemI, Swedish Chemicals Agency Report Nr 7/06.

Swedish Chemicals Agency (2007). Statistics. KemI, Swedish Chemicals Agency.

Swedish Chemicals Agency (2011). KemI-stat (Products and pesticides register). KemI, Swedish Chemicals Agency.

89

Swedish EPA (2007). Siffror om avloppsslam (in Swedish). Swedish EPA http://www.naturvardsverket.se/sv/Start/Verksamheter-med-miljopaverkan/Avlopp/Avlopsslam/Siffror-om-avloppsslam/.

Swedish EPA (2002). Aktionsplan för återföring av fosfor ur avlopp (in Swedish). Swedish EPA Rapport 5214.

Swedish EPA (1990). Provtagnings- och analysmetoder för slam från kommunala avloppsreningsverk (in Swedish). Swedish EPA Rapport 3829.

Swedish EPA (2010). Uppdatering av "Aktionsplan för återföring av fosfor ur avlopp" (in Swedish). Swedish Environmental Protection Agency http://www.naturvardsverket.se/upload/30_global_meny/02_aktuellt/yttranden/Sa_har_vill_vi_aterfora_mer_fosfor_till_kretsloppet/Bilaga_1_Forslag_till_forordning.pdf (Bilaga Z).

Swedish EPA, The Swedish Water & Wastewater Association (VAV), and The Federation of Swedish Farmers (LRF) (1995). Användning av avloppsslam i jordbruket (in Swedish). Swedish EPA Rapport 4418.

Swedish MPA (2011). Prescribed mass of active substance in Sweden. The Swedish Medical Products Agency.

Swedish MPA (2004). Prescribed mass of active substance in Sweden. The Swedish Medical Products Agency.

SWWA (2008). REVAQ - certification system to certify the work in wastewater treatment plants that spread sewage sludge on agricultural land (in Swedish). The Swedish Water & Wastewater Association http://www.svensktvatten.se/Vattentjanster/Avlopp-och-Miljo/REVAQ/om-REVAQ/.

Takacs-Novak, K., Jozan, M., Hermeczi, I., and Szasz, G. (1992). Lipophilicity of antibacterial fluoroquinolones. International journal of pharmaceutics 79, 89-96.

U.S. EPA (1993). Code of Federal Regulations Title 40, Part 503. U. S. EPA.

U.S. EPA (1994a). Methods for the Determination of Metals in Environmental Samples, Supplement 1 (EPA/600/R-94/111). U. S. EPA Drinking Water Methods for Chemical Contaminants (Method 200.7, modified).

U.S. EPA (1994b). Methods for the Determination of Metals in Environmental Samples, Supplement 1 (EPA/600/R-94/111). U. S. EPA Drinking Water Methods for Chemical Contaminants (Method 200.8, modified).

U.S EPA (1994c). Tetra - Through Octa - Chlorinated Dioxins And Furans By Isotope Dilution HRGC/HRMS (Revision B) (method 1613).

UNEP (2001). Stockholm Convention on Persistent Organic Pollutants (POPs). United Nations Environment Programme.

90

Veldhoen, N., Skirrow, R. C., Osachoff, H., Wigmore, H., Clapson, D. J., Gunderson, M. P., Van Aggelen, G., and Helbing, C. C. (2006). The bactericidal agent triclosan modulates thyroid hormone-associated gene expression and disrupts postembryonic anuran development. Aquatic Toxicology 80(3), 217-227.

Voulvoulis, N., Scrimshaw, M. D., and Lester, J. N. (2004). Removal of organotins during sewage treatment: A case study. Environmental Technology 25(6), 733-740.

Westerhoff, P., Yoon, Y., Snyder, S., and Wert, E. (2005). Fate of endocrine-disruptor, pharmaceutical, and personal care product chemicals during simulated drinking water treatment processes. Environmental Science & Technology 39(17), 6649-6663.

WHO (1991a). Tributyl Phosphate. World Health Organization Environmental Health Criteria (112).

WHO (1991b). Triphenyl Phosphate. World Health Organization Environmental Health Criteria (111).

WHO (1998). Flame Retardants: Tris(chloropropyl) Phosphate and Tris(2-chloroethyl) Phosphate. World Health Organization Environmental Health Criteria (209).

Xia, K., Bhandari, A., Das, K., and Pillar, G. (2005). Occurrence and fate of pharmaceuticals and personal care products (PPCPs) in biosolids. Journal of Environmental Quality 34(1), 91-104.

Ying, G.-G., and Kookana, R. S. (2007). Triclosan in wastewaters and biosolids from Australian wastewater treatment plants. Environment International 33(2), 199-205.

Zitomer, D. H., and Speece, R. E. (1993). Sequential Environments for Enhanced Biotransformation of Aqueous Contaminants. Environmental Science & Technology 27(2), 226-244.

Zorita, S., Martensson, L., and Mathiasson, L. (2009). Occurrence and removal of pharmaceuticals in a municipal sewage treatment system in the south of Sweden. Science of the Total Environment 407(8), 2760-2770.

Zuccato, E., Castiglioni, S., Bagnati, R., Melis, M., and Fanelli, R. (2010). Source, occurrence and fate of antibiotics in the Italian aquatic environment. Journal of Hazardous Materials 179(1-3), 1042-1048.

A1

Molecular structures of the compounds included in this thesis.

Adipates

Diethyl adipate (DEAP)

Dibutyl adipate (DBA)

Di-iso-butyl adipate (DIBA)

Di(2-ethylhexyl) adipate (DEHA)

Dioctyl adipate (DOA)

Di-iso-octyl adipate (DIOA)

Didecyl adipate (DDA)

Di-iso-decyl adipate (DIDA)

Biocides

Benzylparabene

Butylparabene

Ethylparabene

Methylparabene

Propylparabene

4-Chloro-3-cresol

O

OCH3

O

O CH3

O

OCH3

O

O CH3

O

O

CH3

CH3

O

O

CH3

CH3

O

O CH3

CH3O

OCH3

CH3

O

OCH3

O

O CH3

O

O

CH3

CH3

O

O

CH3

CH3

O

O CH3

O

OCH3

O

O

CH3

CH3

O

O

CH3

CH3

O

O

OH

O

O

CH3

OH

O

O

CH3OH

O

O CH3

OH

O

O

CH3

OH

OH

CH3

Cl

A2

2-Mercaptobenzothiazole

2-(Tiocyanomethylthio)benzothiazole

N-didecyldimethylammonium chloride (DDMAC)

Propiconazole

Resorcinol

Triclosan (TCS)

Chlorophenols (CPs)

2-monochlorophenol (2-CP)

3-monochlorophenol (3-CP)

4-monochlorophenol (4-CP)

2,3-dichlorophenol (23-CP)

2,4-dichlorophenol (24-CP)

2,5-dichlorophenol (25-CP)

2,6-dichlorophenol (26-CP)

3,4-dichlorophenol (34-CP)

3,5-dichlorophenol (35-CP)

2,3,4-trichlorophenol (234-CP)

N

S

SH

N

S

S

N S

NCl

CH3CH3

CH3CH3

ClCl

N

N

N

O CH3

O

OH

OH

O

OH

Cl ClCl

OH

Cl

OH

Cl

OHCl

OH

Cl Cl

OHCl

Cl

OH

Cl

Cl

OH

Cl

Cl

OHCl

Cl

OH

Cl

Cl

OHCl

Cl Cl

A3

2,3,5-trichlorophenol (235-CP)

2,3,6-trichlorophenol (236-CP)

2,4,5-trichlorophenol (245-CP)

2,4,6-trichlorophenol (246-CP)

3,4,5-trichlorophenol (345-CP)

2,3,4,5-tetrachlorophenol (2345-CP)

2,3,4,6-tetrachlorophenol (2346-CP)

2,3,5,6-tetrachlorophenol (2356-CP)

Pentachlorophenol (PCP)

Butylhydroxytoluene (BHT)

4-Nonylphenol (4NP)

OH

Cl

Cl Cl

OH

Cl

Cl

Cl

OH

Cl

Cl

Cl

OHCl

Cl

Cl

OH

Cl

Cl

Cl

OH

Cl

Cl

Cl Cl

OH

Cl

Cl

Cl

Cl

OH

ClCl

Cl Cl

OH

Cl

Cl

Cl Cl

Cl

OHCH3

CH3

CH3CH3

CH3 CH3

CH3

OH

CH3

CH3

CH3

CH3

A4

Organophosphorus compounds (OPs)

Tributyl phosphate (TBP)

Tris(2-butoxyethyl) phosphate (TBEP)

Triphenyl phosphate (TPP)

2-Ethylhexyl phosphate (EHDPP)

Tricresyl phosphate (TCP)

Tris(2-chloroethyl) phosphate (TCEP)

Tris(2-chloroisopropyl) phosphate (TCPP)

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP)

O

P O

CH3

O

CH3

O

CH3

OPO

O

CH3

O

O

CH3

O

OCH3

O

P

O

O

O

OP

O

O

O

CH3

CH3

O

P

O

CH3O

CH3

O

CH3

OPO

Cl

O Cl

O

Cl

OPO

Cl

CH3O Cl

CH3

O

Cl

CH3

OPO

Cl

Cl

O Cl

Cl

O

Cl

Cl

A5

Organotin compounds (OTCs)

Monobutyltin (MBT)

Dibutyltin (DBT)

Tributyltin (TBT)

Monophenyltin (MPhT)

Diphenyltin (DPhT)

Triphenyltin (TPHT)

Perfluorochemicals

(PFCs)

Perfluorohexane acid (PFHxA)

Perfluoroheptane acid (PFHpA)

Perfluorooctane acid (PFOA)

Perfluorononane acid (PFNA)

Perfluorodecane acid (PFDA)

Perfluoroundecane acid (PFUnA)

Perfluorododecane acid (PFDoDA)

Perfluorotridecane acid (PFTrDA)

Perfluorotetradecane acid (PFTeDA)

CH3

SnH(II)

CH3

Sn(II)

CH3

SnH

CH3

CH3CH3

SnH(II)

Sn(II)

SnH

O

OH

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

OH

O F

F

F

F

F

F

F

F

F

F F

F F

F F

F F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

A6

Perfluorohexane sulfonate (PFHxS)

Perfluorooctane sulfonate (PFOS)

Perfluorodecane sulfonate (PFDS)

Perfluorooctane sulfonamide (PFOSA)

Pesticides

Herbicides

Aclonifen

Alachlor

Aminomethylphosphonic acid (AMPA)

Atrazine

Carfentrazone ethyl

Chloridazon

Chlorpropham

Cinidon ethyl

Cyanazine

S

O

O

O

K

F

F

F

F

F

F

F

F

F

F

F

F

F

S

O

O

O

K

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O S

O

OH

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

S

O

NH

CH3

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

F

O

Cl

NH2N+

O-

O

CH3

CH3 N

O CH3

O

Cl

OP

NH2

OH

OH

N

N

N

NH

CH3

CH3

NH

CH3

Cl

F

ClClO

O

CH3

N

ON

F F

CH3

N

N

OCl

NH2

N

CH3

CH3

O

O

NH

Cl

O

O

N

O

O

Cl

Cl

CH3

CH3

NH

N

Cl

N

NH

CH3

CH3

N

N

A7

Desethylatrazine (DEA)

Desisopropylatrazine (DIPA)

Dichlorobenil

Diflufenican

Ethofumesate

Flurtamone

Glyphosate

Hexazinone

Metabenzthiazuron

Metamitron

Methazachlor

Metribuzin

Pendimethaline

Cl

N

NH

CH3

CH3

N

NH2

N

Cl

N

NH2

N

NH

CH3 N

Cl

Cl

N

N

O

F

F

F

O

NH

F

F

CH3

O

O

OS

CH3

O

OCH3

CH3

O

F

F

F

NHCH3 O

OH

O

NH

P OHOH

OO

N

N

OCH3

N

CH3

CH3

N

CH3 NH

O

N

CH3N

S

NN

CH3

N

NH2 O

CH3

CH3 N

O

Cl

N N

O

N

NH2S

CH3

N

N

CH3 CH3

CH3

CH3

CH3NHCH3

CH3 N+

O-

O

N+O-

O

A8

Phenmedipham

Propyzamide

Prosulfocarb

Simazine

Terbuthylazine

Terbuthylazine desethyl

(DETA)

Terbutryn

Trifluralin

Fungicides

Azoxystrobine

BAM (2,6-dichlorobenzamide)

Bitertanol

Captan

CH3

NH

O

O

NH

O

OCH3

CH3

CH3

NH

O

Cl

Cl

CH

S

O

N CH3

CH3

N

N

N

NH

CH3

NH

CH3

Cl

N

N

N

NH

CH3

CH3

CH3

NH

CH3

Cl

O

N

CH3

CH3

CH3

CH3

NH

N

NHCH3

CH3CH3

N

SCH3

N

CH3

N CH3

N+

O-

O

F

F

F

N+O-

O

N

O

N N

O

O

OCH3

OCH3

NH2

O

Cl

Cl

O

OH

CH3

CH3CH3

N N

N

O

N

SCl

ClCl

O

A9

Chlorothalonil

Cyprodinil

Diphenylamine

Diuron

Fenpropimorph

Imazalil

Iprodione

Isoproturon

Metalaxyl

Pentachloroaniline

Prochloraz

Propiconazole

Pyraclostrobin

N

N

Cl

Cl Cl

Cl

NH

NCH3

N

NH

O

N

CH3

CH3NH

Cl

Cl

CH3

CH3

CH3

CH3N

CH3

O

CH3

Cl

Cl

O

CH2

N

N

Cl

Cl

N

O

NO

NHCH3

CH3

O

CH3

CH3

NH

O

N

CH3

CH3

CH3OO

N

CH3

O

O

CH3

CH3

CH3

NH2

ClCl

Cl

Cl Cl

Cl

Cl

Cl O

N CH3

O

N

N

Cl

Cl

N

N

N

O

CH3

O

O

O

CH3

N

O CH3

O

NN

Cl

A10

Pyrimethanil

Quintozene

Spiroxamine

Thiabendazole

Tolchlofosmethyl

Tolylfluanid

Vinclozolin

Insecticides

Acephate

Aldrin

Azinophosmethyl

Bromopropylate

Carbaryl

Carbofuran

Carbophenothion

NH

N

CH3

CH3

N

O-

N+

O

Cl

Cl

Cl Cl

Cl

CH3

CH3

CH3O

N

CH3

CH3

O

N

N

H

S

N

SP

O

CH3

O CH3

O

Cl

CH3

Cl

CH3

N

CH3

S

O

O

N

S

F

Cl

Cl

CH3

Cl

Cl

N

OCH3CH2

O

O

CH3 O

P

O

NH

CH3

O

SCH3

Cl

ClCl

Cl

Cl

Cl

S

PO

CH3

O

CH3

S

N

NN

O

OHBr

Br

O

O

CH3

CH3

O

O

NH

CH3

O

O

O

CH3CH3

NH

CH3

CH3

OP

S

O

CH3

S

SCl

A11

Carbosulfan

α-chlordane

γ-chlordane

Chlorfenvinphos

Chlorobenzilate

Chlorpyrifos

λ-cyhalotrin

Cyflutrine

β-cyflutrine

α-cypermethrine

Cypermethrine

O

CH3

CH3

O

O

N

CH3

SN

CH3

CH3

Cl

ClCl

Cl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl Cl

Cl

Cl Cl

CH3

O

PO

OCH3

O

Cl

Cl

Cl

O

O

CH3

OHCl

Cl

CH3

O

P

S

O

CH3

O

N

Cl

Cl

Cl

F

F

F Cl

CH3

CH3

O

O

N

O

CH3

CH3 Cl

Cl

O

O

N

F

O

CH3

CH3 Cl

Cl

O

O

N

F

O

Cl

Cl

CH3

CH3

O

O

N

O

Cl

Cl

CH3

CH3

O

O

N

O

A12

DDD-p,p

DDE-p,p

DDT-o,p

DDT-p,p

Deltamethrine

Diazinon

Dichlorvos

Dieldrin

Dimethoate

α-endosulfan

β-endosulfan

Endosulfan sulfate

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl Cl

Cl

CH3

CH3 Br

Br

O

O

N

O

OP

OCH3

O

N

N

CH3

CH3

CH3

S

CH3

O P

OCH3

O

CH3

O

Cl

Cl

Cl

ClCl

O

Cl

Cl

Cl

O

NH CH3

S

P O

CH3

O

CH3

S

Cl

ClCl Cl

Cl

Cl

O

S

O O

O S

O

O

Cl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl

O

SO

OO

Cl

Cl

Cl

A13

Endrin

Esfenvalerate

Fensulfothion

Fenvalerate

Flucythrinate

α-, β-, δ-, γ-HCH (γ-HCH: Lindane)

Heptachlor

Heptachlorepoxide

Keto-endrin

Methidathion

Methoxychlor

Parathion ethyl

Parathion methyl

Cl

ClCl

O

Cl

Cl

Cl

Cl

CH3

CH3 O

O

N

O

CH3

OP

S

O

CH3

OS

CH3

O

CH3

CH3

O

O

N

O

Cl

CH3

CH3

O

O

N

O

O

F

F

Cl Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl

Cl

O

Cl

Cl

Cl

ClCl

Cl

Cl

O

Cl

Cl

Cl

Cl

Cl

S P

OCH3

O

CH3

S

N

O

S

OCH3 N

CH3

O

O

CH3

Cl

Cl

Cl

CH3

OP

S

O

CH3

ON+

O-

O

CH3 O

P

S

OCH3

ON+

O-

O

A14

Permethrine

Pirimicarb

Pirimiphos methyl

Propargite

Propoxur

Pyridaben

Quinalphos

Tetradiphone

Pharmaceuticals

Antibiotics

Ciprofloxacin

Norfloxacin

Ofloxacin

Trimethoprim

CH3

CH3Cl

Cl

O

O

O

CH3

N

CH3O

O

N

N

CH3 CH3

N

CH3

CH3

CH3

N

CH3N

CH3

OP

S

O

CH3

O

CH3

N

CH3

CH3

CH3

OOS

O

O

CH

CH3

NH

O

O

O

CH3

CH3

CH3

CH3

CH3S

ClO

N

CH3

CH3

CH3 N

CH3

OP

S

O

CH3

O

N

N

ClS

O

O

Cl

Cl

Cl

NHN

NO

OH

O

F

NHN

N

CH3

O

OH

O

F

N CH3N

F

O

O

OH

N O

CH3

OCH3

O

CH3OCH3

NH2

N

NH2 N

A15

Hormones

Estriol

Estradiol

Ethinylestradiol

Norethindrone

NSAIDs

Ibuprofen

Naproxen

Ketoprofen

Diclofenac

Tetracyclines (TCs)

Oxytetracycline

Tetracycline

Demeclocycline

Chlorotetracycline

Doxycycline

CH3

OH

OH

OH

CH3

OH

OH

OH

CHOH

CH3

CH3

O

OH

CH

O

OH

CH3

CH3 CH3

CH3

O

CH3

OH

O

O

O

OH

CH3

OH

O

NH

Cl

Cl

H

HOH

H

OOH

CH3 OH

OHOH

O

NH2

O

OH

H N

CH3

CH3

HH

OOH

CH3OH

OHOH

O NH2

O

OH

HN

CH3

CH3

OH O OHOH

O

O

NH2

OH

NCH3 CH3

OHCl

O

NH2

OH

NCH3 CH3

OHOH

OH

OH

Cl CH3

O O

CH3 OH NCH3 CH3

NH2

O

OOH

OOH OH

OH

A16

Phthalates

Dimethyl phthalate (DMP)

Diethyl phthalate (DEP)

Di-n-butyl phthalate (DBP)

Butylbenzyl phthalate (BBP)

Di-(2-ethylhexyl) phthalate (DEHP)

Di-n-octyl phthalate (DNOP)

Di-iso-decyl phthalate (DIDP)

Di-iso-nonyl phthalate (DINP)

O

OCH3

O

OCH3

O

O CH3

O

O CH3

O

O CH3

O

O CH3

O

O

O

O CH3

O

OCH3

CH3

O

O CH3

CH3O

O CH3

O

O CH3

CH3

CH3

O

O

O

O

CH3CH3

O

O

O

CH3

CH3

O

CH3

CH3

A17

Polybrominated diphenyl ethers (PBDEs)

PBDE 28

PBDE 47

PBDE 99

PBDE 100

PBDE 153

PBDE 154

PBDE 183

PBDE 209

Polychlorinated alkanes (PCAs)

Short chain chlorinated paraffins (SCCP)

Medium chain chlorinated paraffins (MCCP)

Long chain chlorinated paraffins (LCCP)

Br

Br

O

Br

Br

Br

O

Br

Br

Br

Br

O

Br

Br

Br

Br

O

BrBr

Br Br

Br

Br

OBr

Br Br

Br

Br

Br

O

Br

Br

Br

Br

Br

Br

O

Br

Br

Br

Br

Br

OBr

Br

Br

Br

Br

Br

Br

Br

Br

Br

CH3

Cl

CH3

CH3

Cl

CH3

CH3

Cl

CH3

A18

Polychlorinated biphenyls (PCBs)

PCB 28

PCB 52

PCB 101

PCB 105

PCB 114

PCB 118

PCB 123

PCB 138

PCB 153

PCB 156

PCB 157

PCB 167

PCB 180

PCB 189

Cl

Cl Cl

Cl

ClCl

Cl Cl

ClCl

Cl

Cl

Cl Cl Cl

ClCl

Cl Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl Cl

Cl

ClCl

Cl

Cl Cl Cl

Cl

Cl

Cl

Cl

ClCl

Cl

Cl Cl

Cl Cl Cl

Cl

ClCl

Cl

Cl Cl Cl

Cl

ClCl

Cl

A19

Planar PCBs

PCB 77

PCB 81

PCB 126

PCB 169

Polychlorinated dioxins/furans (PCDD/Fs)

Polychlorinated dibenzo-p-dioxins (PCDDs)

2,3,7,8-TCDD

1,2,3,7,8-PeCDD

1,2,3,4,7,8-HxCDD

1,2,3,6,7,8-HxCDD

1,2,3,7,8,9-HxCDD

1,2,3,4,6,7,8-HpCDD

OCDD

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

ClOCl

Cl O Cl

Cl

O Cl

ClO

Cl

Cl

Cl

Cl

Cl

Cl

O

ClO

Cl

ClO

O

Cl

ClCl

Cl

Cl

Cl

O

Cl

Cl

ClO

Cl

Cl

Cl

Cl

Cl

O Cl

Cl

Cl

O

Cl

Cl

Cl

Cl

O

Cl

Cl

Cl

Cl

O

Cl

A20

Polychlorinated dibenzofurans (PCDFs)

2,3,7,8-TCDF

1,2,3,7,8-PeCDF

2,3,4,7,8-PeCDF

1,2,3,4,7,8-HxCDF

1,2,3,6,7,8-HxCDF

2,3,4,6,7,8-HxCDF

1,2,3,7,8,9-HxCDF

1,2,3,4,6,7,8-HpCDF

1,2,3,4,7,8,9-HpCDF

OCDF

Cl

O

Cl

Cl Cl

ClCl

Cl

Cl

O

Cl

ClCl

Cl

OCl

Cl

ClCl

Cl

Cl

OCl

Cl

ClCl

Cl

Cl

ClO

Cl

ClCl

Cl

ClO

Cl

Cl

Cl

O

ClCl

Cl Cl

Cl

ClCl

Cl

Cl

ClO

Cl

Cl

Cl

O

ClCl

Cl

Cl

Cl

Cl

Cl

ClCl

OCl

Cl

ClCl

Cl

A21

Polychlorobenzenes (PCBz)

1,2-dichlorobenzene (12CBz)

1,3-dichlorobenzene (13CBz)

1,4-dichlorobenzene (14CBz)

1,2,3-trichlorobenzene (123CBz)

1,2,4-trichlorobenzene (124CBz)

1,3,5-trichlorobenzene (135CBz)

1,2,3,4-tetrachlorobenzene (1234CBz)

1,2,3,5-tetrachlorobenzene (1235CBz)

1,2,4,5-tetrachlorobenzene (1245CBz)

Pentachlorobenzene (PCBz)

Hexachlorobenzene (HCBz)

Polycyclic aromatic hydrocarbons (PAHs)

Fluoranthene

Benzo(b)fluoranthene

Benzo(k)fluoranthene

Benzo(a)pyrene

ClCl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl Cl

Cl

Cl

Cl

Cl

Cl

Cl

ClCl

Cl Cl

Cl

Cl

Cl Cl

ClCl

Cl Cl

Cl

ClCl

Cl Cl

Cl

Cl

Cl

Cl

A22

Benzo(g,h,i)perylene

Benzo(g,h,i)perylene

Siloxanes

Octamethylcyclotetrasiloxane (D4)

Decamethylcyclopentasiloxane (D5)

Dodecamethylcyclohexasiloxane (D6)

Hexamethyldisiloxane (MM)

Octamethyltrisiloxane (MDM)

Decamethyltetrasiloxane (MD2M)

Dodecamethyltetrasiloxane (MD3M)

Terpenes

d-, l-limonene

CH3Si

CH3O

Si

CH3

CH3

O

SiCH3

CH3

OSi

CH3

CH3

O

CH3Si

CH3OSi

CH3CH3

O

Si

CH3

CH3 O

Si

CH3 CH3

O

Si

CH3

CH3

O

CH3Si

OSiO

Si

O

Si

O Si

CH3CH3

O

Si

O

CH3

CH3CH3

CH3

CH3

CH3

CH3CH3CH3

CH3Si

CH3

CH3

OSi

CH3

CH3

CH3

CH3

Si

CH3

CH3OSi

CH3

CH3

O

Si

CH3

CH3

CH3

CH3

SiCH3

CH3

O

Si

CH3

CH3

OSi

CH3

CH3

O

Si

CH3

CH3

CH3

CH3

Si CH3

CH3O

SiCH3

CH3

O

Si

CH3CH3

OSi

CH3

CH3

OSi

CH3

CH3 CH3

CH2

CH3

CH3