Wastewater treatment plants : wastewater resource … · Wastewater treatment plants : wastewater...

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C. Wisniewski Montpellier University, France UMR QualiSud Faculté des Sciences Pharmaceutiques et Biologiques Wastewater treatment plants : wastewater resource recovery facilities ? Wastewater treatment plants : wastewater resource recovery facilities ?

Transcript of Wastewater treatment plants : wastewater resource … · Wastewater treatment plants : wastewater...

C. Wisniewski Montpellier University, France

UMR QualiSud

Faculté des Sciences Pharmaceutiques et Biologiques

Wastewater treatment plants : wastewater

resource recovery facilities ?

Wastewater treatment plants : wastewater resource recovery facilities ?

OUTLINES Current state of Wastewater Treatment (WWT) Climate Change's Relation to Wastewater Treatment A new Paradigm for Wastewater Treatment Plant (WWTP)

Wastewater treatment plants : wastewater

resource recovery facilities ?

Wastewater Treatment adaptation according to Climate Change

Wastewater treatment plants : wastewater

resource recovery facilities ?

WASTEWATER

WASTEWATER TREATMENT PLANTS

DISCHARGED IN WATER BODIES

Urban and agricultural runoff

Municipal sewage effluent Industrial effluent

Parameter mg/L

TSS 250 to 600

COD 500 to 1200

BOD 230 to 560

N total 30 to 100

P total 6 to 25

Level of treatment required before discharge imposed by European Directives

Wastewater treatment plants : wastewater

resource recovery facilities ?

Urban Wastewater Treatment Directive (91/271/EEC1)

Protection of the aquatic environment from the adverse effects (such as eutrophication) of urban (and industrial) wastewater

Phosphorus and Nitrogen

Sensitive areas

Collection and treatment of wastewater in all agglomerations with a population equivalent larger than 2000

Parameter mg/L % reduction

COD 125 75

BOD 25 70 - 90

N total 10 - 15 80

P total 1 - 2

Objective

Implementation and Improvement of many WWTPs the last few years…

SIGNIFICANT IMPACT ON WASTEWATER TREATMENT

Wastewater treatment plants : wastewater

resource recovery facilities ?

Water Framework Directive (2000/60/EC2000)

Protection and restoration of clean water across Europe

Identification of priority substances that have to be reduced in water bodies

Achieve “good status” by 2015 and to prevent deterioration to water bodies

Objective

Implementation of additional treatment steps in many WWTPs …

Micro-pollutant

Emerging contaminants

Primary treatment

Wastewater treatment plants : wastewater

resource recovery facilities ?

Secondary treatment

Pre-treatment Tertiary treatment

CONVENTIONNAL WASTEWATER PLANT… TODAY

DISCHARGE

Removal of suspended solids

(settling)

Removal of organic matter and of some nutrients

(aerobic or anaerobic processes)

Improvement of the effluent quality before

its discharge (effluent polishing)

Primary treatment

Wastewater treatment plants : wastewater

resource recovery facilities ?

Secondary treatment

Pre-treatment Tertiary treatment

Sludge treatment DISCHARGE

CONVENTIONNAL WASTEWATER PLANT… TODAY

Wastewater treatment plants : wastewater

resource recovery facilities ?

A SIMPLE WASTE TREATMENT UNIT … REQUIRING ENERGY … PRODUCING SLUDGE

ENERGY SLUDGE

CLIMATE CHANGE

What is the future of WASTEWATER TREATMENT plants?

CONVENTIONNAL WASTEWATER PLANT… TODAY

Wastewater treatment plants : wastewater

resource recovery facilities ?

Climate Change Impact on WWT

WWT Impact on Climate Change

CLIMATE CHANGE

What is the future of WASTEWATER TREATMENT plants?

Wastewater treatment plants : wastewater

resource recovery facilities ?

More intensive rainfall events

Extreme weather events

Higher climate variability

Very few references on the assessment of climate change

impacts on WWT

Increased evaporation rates

Changes in frequency and timing of precipitation events

Earlier snowmelt

Temperature elevation

Climate Change Impact on WWT

Wastewater treatment plants : wastewater

resource recovery facilities ?

Changes in frequency and timing of precipitation events

Temperature elevation

Increase of sewage influent

PEAK FLOW RATES Large majority of existing

sewers in most EU countries

Combined sewers

Modifications of SOLIDS-LIQUID SEPARATION

Modification of BIOLOGICAL REMOVAL RATES

Conventional Process models unable of describing and predicting

the effects of SHOCK-LOADING EVENTS

Water Sci Technol. 2009, 60(2):533-540

Wastewater treatment plants : wastewater

resource recovery facilities ?

SIGNIFICANT IMPACTS on the overall environmental performance

GREENHOUSE GAS (GHG) EMISSIONS

ENERGY SLUDGE

WWT Impact on Climate Change

Wastewater treatment plants : wastewater

resource recovery facilities ?

Intergovernmental Panel on Climate Change (IPCC), 2007 .

Global Greenhouse Gas Emissions by Source (USA)

GHG emissions from

wastewater represent 0,6 %

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resource recovery facilities ?

GHG emissions

CO2

CH4

N2O

N2O

CH4 Sludge thickening and disposal

Nitrous oxide (N2O) Carbon dioxide (CO2) Methane (CH4)

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resource recovery facilities ?

CO2

CH4

N2O

N20

CH4 Sludge thickening and disposal

Nitrous oxide from nitrification/denitrification processes

Carbon dioxide from aerobic process

Methane from anaerobic processes

Managing Water Resources under Climate Uncertainty, Part of the series Springer Water. 2001 : 197-220

Wastewater treatment plants : wastewater

resource recovery facilities ?

REMOVE ORGANIC MATTER NITROGEN PHOSPHOROUS Micropollutant

GENERATE SOLID WASTE GHG

CONSUME ENERGY

Wastewater treatment plants : wastewater

resource recovery facilities ?

FACTORY Resources recovering and recycling

Treatment and disposal ENERGY SLUDGE

GHG

A NEW PARADIGM FOR WWTP IS NOW NECESSARY

WHAT CAN WE GET FROM WASTEWATER?

Extracting resources from wastewater is not new … but becomes crucial

WHAT CAN WE GET FROM WASTEWATER?

Wastewater treatment plants : wastewater

resource recovery facilities ?

Water (for reuse)

Energy

Nutrient

Other value-added materials…

http://www.biocycle.net/2014/08/14/power-positive-resource-recovery/

Wastewater treatment plants : wastewater

resource recovery facilities ?

Energy

http://www.biocycle.net/2014/08/14/power-positive-resource-recovery/

There is more energy in wastewater than is required to treat it

There are different types of energy in wastewater

Heat Energy

Biological/chemical Energy

0.05 kW

1 m3/d

0.26 kW assuming that a 12° change in

temperature could be extracted

Energy demands

0.02 kW

15 times higher than the energy required for

treatment

In the ORGANIC MATTER

Wastewater treatment plants : wastewater

resource recovery facilities ?

http://www.biocycle.net/2014/08/14/power-positive-resource-recovery/

Heat Energy

Biological/chemical Energy

0.05 kW

0.26 kW assuming that a 12° change in

temperature could be extracted

Low-grade heat Low energy quality

Any significant amount of power produced

In the ORGANIC MATTER

40% of this energy can be converted into electrical power

0.02 kW

Power Positive Wastewater Treatment power production equivalent to the power demand

Wastewater treatment plants : wastewater

resource recovery facilities ?

Energy

http://www.ajol.info/index.php/wsa/article/view/115257/104844 http://www.biocycle.net/2014/08/14/power-positive-resource-recovery/

Aerobic treatment requires air and demands more power than anaerobic treatment that produces biogas that can be used to fuel power production.

LARGE DEVELOPMENT OF ANAEROBIC PROCESSES FOR ORGANIC MATTER REMOVAL

Research about conversion of digester gas (methane) into methanol

Anaerobic digestion might be coupled with other process to produce methanol, ammonia, or other products from digester gas.

Wastewater treatment plants : wastewater

resource recovery facilities ?

Nutrient Recovery

Abundant in the atmosphere BUT

takes a considerable energy input to capture it and convert

it into a fertilizer product

Volatility of the natural gas market

NITROGEN PHOSPHOROUS

Non-renewable resource for which there is no substitute

Rise in P prices due to

increasing fertilizer demand

MOTIVATIONS

Wastewater contains nutrients such as phosphorus and nitrogen

Wastewater treatment plants : wastewater

resource recovery facilities ?

PHOSPHOROUS

http://inside.bluetechresearch.com/streams/themes/nutrient-recovery-energy-and-resource-recovery/

Approximately 18% of the EU’s total phosphorus goes into sludge and could be recycled

Many countries are starting to promote measures to recover phosphorus from wastewater

Sweden Switzerland

UK and Germany

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resource recovery facilities ?

PHOSPHOROUS

Water Pollution . 2015, 1 (3) : 155-166

Ion exchange and adsorption

Bio-electrochemical system

Membrane separation

NITROGEN

Chemical precipitation

Biological assimilation

Chemical reduction and extraction

Physical-chemical adsorption and ion exchange

Physical filtration and membrane process

Wastewater treatment plants : wastewater

resource recovery facilities ?

Nitrogen and Phosphorus recovered by precipitation (e.g. struvite)

Both Phosphorus and Ammonium can be simultaneously removed and precipitates can be used as a fertilizer.

Separation of urine and solids

Urine accounts for only 1% of the total volume of wastewater, but it contains up to 80% of all the nutrients.

NITROGEN and PHOSPHOROUS

Urine contains phosphate (PO4) and ammonium (NH4). When magnesium (Mg) is added to urine, phosphate, ammonium and magnesium bind and form struvite (MgNH4PO4•6H2O), which can then be filtered out, collected, and dried into a powder

http://www.sswm.info/content/struvite-0

Wastewater treatment plants : wastewater

resource recovery facilities ?

NITROGEN and PHOSPHOROUS

The process is distinguished by the fact that municipal sewage sludge from wastewater treatment plants with simultaneous phosphate elimination with iron salts could be used without any changes in the process of wastewater treatment. The resulting product can be applied, for example, directly as fertilizer in agriculture.

http://www.iswa.uni-stuttgart.de/lsww/forschung/awt/2012_2013_Forschungsprojekte/Pilotanlage_MAP.en.html

Large-scale Application of Phosphorus (Struvite) Recovery from Digested Municipal Sludge

"Stuttgart Process"

Wastewater treatment plants : wastewater

resource recovery facilities ?

Other value-added materials…

Environ. Sci. Technol. 2015, 49 (16): 9479–9488

U.S. sewage sludges were analyzed for 58 elements by ICP-MS and

electron microscopy

Identification of 13 lucrative elements

Platinum, silver, iron, zinc, copper, gold

€ 2 million

1 ton of sludge

16,7 g Ag - 0,33 g Au

Wastewater treatment plants : wastewater

resource recovery facilities ?

LIST OF MATERIALS THAT CAN BE POTENTIALLY EXTRACTED FROM WASTEWATER

Nutrient Recovery: State of the Knowledge 2011, Water Environment Research Foundation

PHA (polyhydroxyalcanoate) Production

Biopolymers of commercial interest

PHA storage is a widespread bacterial property

Wastewater treatment plants : wastewater

resource recovery facilities ?

Water Reuse

DEMAND FOR ALTERNATIVE POTABLE

SUPPLY SOURCES

CLIMATE CHANGE

Decrease in the availability of freshwater

Deterioration of freshwater

resources

Wastewater reuse will become more necessary as climate change accelerates

Primary treatment

Wastewater treatment plants : wastewater

resource recovery facilities ?

Secondary treatment

Pre-treatment Tertiary treatment

Sludge thickening and disposal

R

E

U

S

E

Primary treatment

Wastewater treatment plants : wastewater

resource recovery facilities ?

Pre-treatment

Sludge thickening and disposal

Membrane bioreactor (MBR)

R

E

U

S

E

High wastewater discharge quality

High level of wastewater recycling

Primary treatment

Wastewater treatment plants : wastewater

resource recovery facilities ?

Pre-treatment

Sludge thickening and disposal

Membrane bioreactor (MBR)

R

E

U

S

E

Increase of the global market for membrane bioreactors

A new paradigm for WWTPs

Wastewater treatment plants : wastewater

resource recovery facilities ?

FACTORY Resources recovering and recycling

Treatment and disposal

Effective and cost efficient Without side-effects Promoting equity Technically and socially feasible Preventing long term negative effects

MESURES

Wastewater treatment plants : wastewater

resource recovery facilities ?

What limits will be imposed?

How much will it cost and who will finance it?

Changes in polices and regulations

Changes in public attitude (e.g. to use reclaimed water)

… wastewater reuses, and energy and nutrient recovery from wastewater have to be actively encouraged

A new paradigm for WWTPs Nutrient factory

Energy factory

Water factory