Katarína DercováLaboratory of Environmental BiotechnologyInstitute of BiotechnologyFaculty of Chemical and Food TechnologySlovak University of Technology, Bratislava

Environmental and Technical Aspects of PCB Disposal, Properties, Monitoring, Destruction, and

Remediation of PCB-contaminated sites

„Non-Combustion Demonstration Project in Slovakia“

Regional Training Workshop on PCBs and POPs Wastes, Bratislava, Slovakia, December 1- 4,, 2009

Outline of the presentation

International Commitments on POPs

The fate of PCBs in the environment

History of the PCB production in Slovakia; Characterization of PCB-contaminated areas - „old environmental burdens“;

Non-Combustion Demonstration Project in Slovakia – a current effort to remediate PCB-polluted areas in accordance with Stockholm Convention on POPs; Problems and solutions

PCB destruction technologies – some promising non-combustion physico-chemical and biological remediation technologies – principles, advantages, and limitations

Conclusions

POPs (PCBs) – serious ecological problemslow degradabilityhigh hydrophobicitylow water solubilityhigh lipid solubilitybioaccumulation in biota

high toxicity semi-volatilityhigh sorption capacitylow chemical reactivityhigh chemical stabilitypersistence in the environment

Due to migration of POPs at long-range distances from their original source, it is necessary to deal with the release of POPs to the environment at multinational level

International Conventions:

Stockholm Convention on POPs Basel Protocol on Long-range Transboundary Air Pollution

Slovakia – party to the international commitments

Basic assessment of „dirty dozen“global production

A Dioxins 10,5 tB PCBs 1.5 mil. tC HCB 1-2 mil. tD Mirex (no data avail.)E Chlordan 70,000 tF DDT 2,8-3 mil. t

G Aldrin 240,000 tH Dieldrin 240,000 tI Endrin 3,12 mil. t

J Toxafen 1,33 mil. tK Heptachlor 900 t

Stockholm Convention requires from the signatories to take measures for source elimination of 12 „old“ and 9 „new“ substances

belonging to POPs including PCBs Safe destruction of PCBs by the year 2010 is required

from the EU member states including Slovakia!

PCBs• 31% - escaped

into the environment

• 65% - still being used in closed

systems

• 4% - disposed in incinerators

C12H10-(x+y)Clx+y x + y = 1 – 10 chlorines

209 PCB congeners

2. PCBs

Clx Clypara

meta

meta

ortho ortho

ortho ortho

meta

meta

para4'

6' 5'

23 2' 3'

4

5 6

Undiserable effects on human health:chloracne, liver diseases, reproduction anomalies, carcinogenesis, neurotoxicity, estrogenic effects – imitators and blockers of hormones – PCBs are considered „endocrine disruptors“

The fate of PCBs in the environment - controlled by a combination of interacting processes classified as:physical – responsible for movement of PCBs away from their sourcechemical and biological – determine the extent to which PCBs will be transformed. Transformations occur abiotically or biotically (by MO).PCBs – the most hydrophobic anthropogenic (man-made) compounds!Decachlorobiphenyl has 108 times higher affinity to lipid than to water compartment!

Cl

ClClCl

ClCl

Cl

ClCl

Cl

zrkadlový obrazPCBs - Atropoisomeric compounds (enantiomers)

Clm

Cln

former producerChemko StrážskeProduction: 21,500 tons

Slovakia belonged to the 8 largest world PCB-producer

3. History of PCB Production3. History of PCB Production

About 50% of production -exported; 50% used in the territory of former Czechoslovakia (today Czech and Slovak Republic)

PCB Manufacture in Slovakia1959 - 1984

Year

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

0200400600800

100012001400160018002000

PCB production (tons)

Cl m

Cl n

n = 1 - 5 m = 0 - 5

APIROLIO (Italy) AROCLOR (U.K., U.S.A.) ASBESTOL (U.S.A) ASKAREL (U.K., U.S.A.) BAKOLA 131 (U.S.A.) CHLOREXTOL (U.S.A.) CLOPHEN (Germany) DELOR, DELOTHERM, HYDELOR (Czechoslovakia) DK (Italy) (Factory Chemko Strážske)DIACLOR (U.S.A.) DYKANOL (U.S.A.) ELEMEX (U.S.A.) FENCLOR (Italy) HYDOL (U.S.A.) INTERTEEN (U.S.A.) KANECLOR (Japan) NOFLAMOL (U.S.A.) PHENOCLOR (France) PYRALENE (France) PYRANOL (U.S.A.) PYROCLOR (U.K.) SAFT-KUHL (U.S.A.) SOVOL (U.S.S.R.) SOVTOL (U.S.S.R.)

PCB commercial mixtures brand names:

Commercial mixtures of PCBslow dielectric constant, high boiling point, good fire resistance, good ageing properties with no deteriorationin service make them ideal for use as:

Delor 103 ~ Aroclor 1242

Dielectric & insulating fluidsDelor 106 ~ Aroclor 1260

Synthetic paint additives, plasticizersDelotherm

Heat exchanger fluids

HydelorHydraulic fluids

capacitors

transformers

1.5-20 kg PCBs

OPEN SYSTEMS (prohibited)CLOSED SYSTEMS (still can be used)

600 tons PCB wastes from production (semi-solid residues from former production – hardly manipulable material of a semifluid consistence – biphenyls and terphenyls)

1,500 tons PCB-containing equipment – at present, there are registered: 400 pieces of transformers, 30,000 pieces of capacitors, and 400 pieces of other equipment

1,500 tons various wastes - stockpiles of contaminated hydraulic and transformer oils with PCB contents, scraps of PCB–dyes...at Pláne waste dump (in the vicinity of the former producer) -additional 900 tons of PCBs from production

Inventory of PCB stockpiles –current existence of ∑3.600 tons

Storage of the unused PCB products

Solid PCB distillation residues with expected high dioxin level

Barrel corrosion and drums with biphenyls and terphenyls

Chemko FactoryChemko Factory

Laborec River

Strazske TownStrazske Town

„Environmental Burdens“Hot spot and urgent problem in Slovakia

0

100

200

300

400

500

600

ng/g

fat

Braz

il Fiji

Phili

ppin

esAu

stra

liaHu

ngar

yNe

w Zea

land

Bulg

aria

Chin

aUS

AIre

land

Finl

and

Egyp

tNo

rway

Croa

tiaUk

rain

eRu

ssia

Swed

enRo

man

iaNe

ther

land

sBe

lgiu

m

Germ

any

Luxe

mbo

urg

Spai

nIta

ly Sl

ovak

Rep

.Cz

ech

Rep.

Holoubek, Recetox (2006)

PCB levels in the human population

The number of indicator-PCBs: (28, 52, 101, 138, 153, 180) in mother milk (Holoubek, 2006)

NRC-Diox / IPCM

1The former producer Chemko Strážske2 The former producer´s effluent canal3 Laborec River4 Inflow canal (for ZŠ)5 Zemplínska šírava water reservoir6 Outflow canal

5 km long

33.5 km2

(Kočan et al., 2007)

• An essential, integral and dynamic part of the hydrological system• Important source of nutrients – application to soil• Ultimate reservoir for the chemical and biological contaminants – the

potential to pose ecological and human health risks• Several hundred tons of PCBs have been released into the environment -

hydrophobic properties - PCBs tend to be adsorbed by the aqueous sediment - an abundant PCB source causing contamination of the waters of Eastern Slovakia

Contaminated sediments

PCBs in sedimentsEffluent canal: 1 – 10 g/kg of sed.d.w.

Laborec River: 0.1 - 1 g/kg

Zemplínska Šírava: 0.001 - 0.1 g/kg

Effluent canalLaborec River

Zemplínska Šíravawater reservoir

Initial approximation assumes: 40,000 tons of PCB-contaminated sediments

8,5

2400

6000

3900

1600

Domasa Lake

Zemplinska Sirava Lake

Filling canal (for ZS)

Laborec / downstream Strážske

Sewage canal / Strážske town

Chemko effluent canal

ppb (dry sediment)

Polluted Area

Control Area

PCB Levels in Sediment Samplespolluted area vs control area

3 000 000 = 0.3 % 3-5 kg/t of dry mud!

2.4 mg/kg

0.008 mg/kg

(Kočan et al.)

224

375

1,5

5,2

Planktonophage+benthic

Predatory

Planktonophage+benthic

Predatory

ppm (sum of all congeners, lipid weight)

Stropkov –control waters

Michalovce - polluted waters

PCB Levels in FishPolluted waters vs Control waters

(Kočan et al., 1998)

„Goldfish“ 15-220-fold content of PCBs compared to the rest of Slovakia

Consumption of fish is banned for future 25 years!

4. „NON-COMBUSTION PROJECT"Global Program

„Demonstration of Viability and Removal of Barriers that Impede Adoption and Effective

Implementation of Available, Non-combustion Technologies for Destroying

Persistent Organic Pollutants“

Non-Com project

0500

10001500200025003000350040004500

Slovakia Philippines China Africancountry

PCB equipmentPCB wastesPOPs PesticidesContaminated soil

targeted wastes

NigeriaNigeria

Non-Com project

Project Objective

supply of high-tech non-combustion technology for disposal of chlorinated substances, namely

polychlorinated biphenyls and chlorinated obsolete pesticides

The following facilities will be provided by the grant:1. technological unit for PCB destruction

(PCBs from liquid and bulk solids) 2. extraction unit

(PCB extraction of solid matrix - sediments and soils)

Non-Com project

Project structureThe project is realized by the attendance of the following subjects:

Donator organization – GEF (Global Environmental Facility - financing organization)Implementing agency - UNDP (United Nations Development Programme)Executive agency - UNIDO (United Nations Industrial DevelopmentOrganization)

Slovak partners are: Ministry of the Environment of SR (MoE SR), Public Sector Consortium (Kosice Self-governing Region, the town of Michalovce, the town of Strazske and the Slovakian Hydro-economic enterprise) Private Sector Consortium (company Chemko a.s. and local Slovak Non-Governmental Organizations)

Project scheduleProject will last six years (72 months)

The first 24 months – would involve tendering process, obtaining necessary operating permits, impact analyses; designing, constructing and testing technology to be deployed; planning and organizing comprehensive public participation, involvement monitoring, and evaluation plan.

The next 18 months – would involve actual destruction of 600 tons of PCB contaminated product, targeted stockpile and waste residues from the formal PCB production; another 400 tons of PCB waste will be collected from the PCB waste owners; implementation of broadly based public participation and involvement plan, and initiation of the rigorous monitoring and evaluation plan.

Following 30 months would involve destruction of 1,500 tons of PCB waste from the state sector and contaminated equipment owners in Slovakia and activities related to the destruction of PCB concentrate from decontamination activities of highly contaminated sediments and soil.

The last 6 months would be committed to the comprehensive assessment of overall project results, including lessons learned and the definition of concrete mechanisms for successful replication at the regional and global levels, and the technology transfer process.

• Preparatory phase

• Technology performance

• Results dissimination activities

Proposal for Financial AssuranceTotal expenses of the project are proposed to 20,155,040 USD and

represents following items:

TOTAL GEF 10,004,040.- USD

Cofinancing SRGovernment of SR represented by MoE SR 2,000,000.- USDPublic sector consortium 1,000,000.- USDPrivate sector consortium 6,121,000.- USD

(including 2,00,000 USD guaranteed by MoE as payments of PCB waste and equipment holders for disposal at non-combustion unit)

TOTAL SR 9,121,000.- USD

Cofinancing otherUNIDO 665,000.- USDUNDP 95,000.- USDNon-governmental organizations 270,000.- USDTOTAL other 1,030,000.- USD

TOTAL COFINANCING 10,151,000.- USD

TOTAL EXPENSIES OF THE PROJECT 20,155,040.- USD

„Non-Combustion Project

Selection of Project technology

Final selection of technology was realized through transparent, two-step international tendering process in accordance with UNIDO Financial Rules and Regulations and Procurement Manual within the project realization.Potentially appropriate types of technologies tentatively identified by TAG (Technical Advisory Group) documents were these best over-elaborate technologies:GPCR – Gas Phase Chemical ReductionBCD – Base Catalyzed Decomposition Solvated Electron Technology – reaction in flowing electrons mediumSodium Reduction – reduction by dispersive sodium in mineral oil

Non-Com project

Non-Com project

5. Available technologies for destruction of POPs (PCBs)

1) High temperature destruction - combustion or non-combustion technologies (plasm arc, pyrolysis,molten salt oxidation)2) Oxidative non-combustion technologies -supercritical water oxidation, catalytic oxidation, mediated electrochemical oxidation3) Reductive technologies - dehalogenation or reduction4) Photolytic destruction technologies5) Biological technologies – Bioremediation and Phytoremediation (economical and ecological alternative of physico-chemical methods) for remediation of PCB-contaminated sites

Non-Com project

Non-Combustion Technologies- Selection Criteria (highlights)

Operate in systems that are essentially closedHigh total destruction efficiencies (DEs)Available non-combustion technologies has to meet the

Stockholm Convention requirements to ensure the use of Best Available Techniques (BAT) and ensure Best Environmental Practices (BEP)

Suitable for the matrices specific for the countryTechnologies that are already commercially available

Non-Com project

Advantages of non-combustion technologies

Intrinsically low environmental impact

Mobility and scalability

Diversity - can be adjusted for a variety of applications

Products can be re-usableTechnically Environmentally Economically feasible sollutions for POPs destruction

CxHyClxOz + H2 CH4 + H2O + HCl(> 850 °C)

CH4 + H2O 3 H2 + CO (steam reforming, catalytic)CO + H2O CO2 + H2 (water-gas shift, catalytic)

CxHyClxOz + H2 CH4 + H2O + HCl(> 850 °C)

CH4 + H2O 3 H2 + CO (steam reforming, catalytic)CO + H2O CO2 + H2 (water-gas shift, catalytic)

GPCR(Gas Phase Chemical Reduction)

Advantages Excellent DE99.9999 %

Low amounts of solid residuesAll types of wastes, mobility,

scalabilityAll emissions and residues may

be captured for assay and re-processing

Limitations, disadvantagesComplexity

Safety issue related to hydrogenCostly for low strength wastes

or small scales

GPCR involves the reduction of organic compounds by hydrogen and some steam (which acts as a heater transfer agent and another source of hydrogen) at temperature of 850°C or greater. Organic compounds (POPs) are ultimately reduced to methane, hydrogen chloride (if the waste is chlorinated), and minor amounts of low molecular weight hydrocarbons (benzene and ethylene). Water shift reaction - improve decomposition.

The hydrochloric acid is neutralized by addition of caustic soda during initial cooling of the process gas, or can be taken off in acid form for reuse.Cooled, scrubbed gas from the reactor is compressed, analyzed, and re-used as a fuel for plant components.

Gas-Phase Chemical ReductionTM

Block Flow DiagramGas-Phase Chemical ReductionTM

Block Flow Diagram

Liquid Waste PreheaterSystem (LWPS)

TORBEDTM ReactorSystem

Thermal Reduction Batch Processor (TRBP)

Gas-PhaseChemicalReduction(CPCRTM)Reactor

Gas ScrubbingSystem

Product GasCompression and

Storage

Contaminated

Liquids

Contaminated

Solid/Sediment

Contaminated

Bulk Solids

Clean Solids Clean Water

Gas

Liquid

Solid

AuxiliaryBurner

Rec

ircu

lati

on

Gas

Fuel

for

Fro

nt -

end

S yst

ems

Front-end units differ depending on the waste matrix

I. II. III.

Technology can be broken down into 3 basic unit operations:The front-end system (where the contaminants are rendered into a suitable form for destruction in the reactor), the reactor ( which reduces the contaminants, now in gas phase using hydrogen and steam), and the gas scrubbing and compression system.

Liquid and solid wastes are placed into TRBP (Thermal Reduction Batch Processor), heated to 600°C in a hydrogen-rich (oxygen deficient) atmosphereContaminants that volatilise off of the solids and liquids are then swept into the GPCR reactor for destruction.

Experience:Australia, Japan, Canada, USA

Described as non-conventional heterogeneous catalytic hydrogenation process in which PCBs react with an alkali metal hydroxide, a hydrogen donor and a proprietary catalyst to produce salts, water and carbonaceous residue. When heated to about 300°C, the reagent produces highly reactive atomic hydrogen, which cleaves chemical bonds that confer toxicity to compounds.Oil and catalyst may be recovered for re-use.

currently operates in CzR

BCD (Base Catalyzed Decomposition)RCl + NaOH + [H] RH + NaCl + H2O

(catalyst, T = > 320°C, nitrogen blanketing)[H] is the hydrogen donor

RCl + NaOH + [H] RH + NaCl + H2O(catalyst, T = > 320°C, nitrogen blanketing)

[H] is the hydrogen donor

Na Na+ + e- (in liquid NH3)RCl + Na+ R+ + NaCl, NaNH2, R+ …

Na Na+ + e- (in liquid NH3)RCl + Na+ R+ + NaCl, NaNH2, R+ …

AdvantagesNo formation of dioxins/furans

No data emissions was identifiedMobile units and multiple capacities

Applicable to soils, solids, liquids, transformers, capacitors

Limitations, disadvantagesDewatering needed prior to treatment

Use of sodium requires precautions Ammonia useHigh pressure

Licensing: USA

SET (Solvated Electron Technology)

Solvated electron solutions are produced by dissolving sodium metal in anhydrous ammonia at room temperature. The solvated electrons reduce PCBs to sodium chloride, sodium amide, and petroleum hydrocarbons. Materials with a high water content must be de-watered prior to treatment.

Alkali Metal ReductionSodium Reduction Technology

Treatment of wastes with dispersed metallic alkali in mineral oil. Metallic alkali reacts with chlorine to produce salt and non-halogenated wastePCB destruction reaction by-products include:SODIUM CHLORIDE (table salt that could be used in industrial processes or road ice melting agent)POLYPHENYL (hydrocarbon without chlorine that could be used as a clean fuel in industrial furnaces) SODIUM HYDROXIDE (common chemical used in industry) MINERAL OIL (re-usable transformer oil)

RH10-x Clx + Na NaCl + RH10-xClx-1

RH10-x Clx + H RH10-x+1Clx-1

Efficacy: < 2 ppm – for treated oil; PCB < 0.5 ppm; dioxins < 1 ppb for solid residues.

Applicability: PCBs to 10 000 ppm

Recommended for Slovakia:

Pure PCBs

KINECTRICS (R&D Division of Ontario Hydro, Canada)

Sodium ReductionPCB contaminated oilOther POPs

PCBcontaminated electrical

equipmentSolvent extraction

PCB contaminated soil

Thermal desorption

Concentrated PCB residues

Concentrated PCB residues

Clean oil can be re-used in electrical transformers

NaCl, NaOH,

Petroleum based

byproduct

Complete PCB destruction

Process operates at atmospheric pressure and temperature between 90 – 165 °C.Treatment can take place either in situ or ex situ

Process diagram:

Alkali-Metal-Reduction

Process Flow Schedule in Canada (fixed plant)

North America, Germany, France, Spain, Iran, Japan

Commercialized variation: Sodium Powder Dispersion Process (Japan, Okayama 2002)

Non-Com project

Oil flows from a feed tank to the processing unit and then to a treated oil tankOn-line treatment:oil flows from atransformer unit to–processing unit and then to transformer unit

Used widely for removal of PCBs from transformers.

Plant Toyota CityFirst foreign PCB destruction technology approved in Japan

BioremediationWhat is bioremediation?

Returning the environment to its original state using biological processes

Bioremediation can be defined as any process that uses microorganisms (mainly bacteria), fungi, green plants or their enzymes to return the

environment altered by contaminants to its original condition, to transform toxic compounds

to less toxic or non-toxic intermediatesTotal decomposition of POPs to carbon dioxide, water, and

biomass is called mineralization

C l

C l

O 2

oxygenase

H O H O H

H

C l

C l

dehydrogenase

-H 2

O H O H

H

H

C l

C l

dioxygenase

O 2

C l

O C O O H

O H C l

hydrolase C l

C O O H

I II III IV V

.

Aerobic degradation of PCBsUpper catabolic pathway

Chlorobenzoic acid -

- Accumulation or degradation to CO2 and

H2O

BDO

bphA bphB bphC

Meta-cleavageproduct2,3-dihydroxybiphenyl

biphenyl-cis-2,3-dihydrodiol

PCBs

bphD+2-

hydroxy-penta-

2,4-dienic acid

2-hydroxy-6-oxo-6-phenylhexa-2,4-dienic acid

C l

C l

O 2

oxygenase

H O H O H

H

C l

C l

dehydrogenase

-H 2

O H O H

H

H

C l

C l

dioxygenase

O 2

C l

O C O O H

O H C l

hydrolase C l

C O O H

I II III IV V

bphA bphB bphC

Meta-cleavageproduct2,3-dihydroxybiphenyl

biphenyl-cis-2,3-dihydrodiol

PCBs

bphD+2-

hydroxy-penta-

2,4-dienoic

acid

Most of the PCB-degrading bacteria do not have the completegenetic information for „upper“ and „lower“ metabolic pathways!

Isolation (or construction) of microorganisms with high degradation and survival potential –

the essential assumption of successful bioremediation technology!

„Upper“ catabolicpathway

„Lower“ catabolicpathway

biphenyldioxygenase

Strategies for bioremediationBiostimulation – nutrients (N, P) and oxygen are added to encourage the growth and activity of indigenous microbial consortium (bacteria) already existing in the soil or water Bioaugmentation - adapted or designed (GMO) microorganisms that can

clean-up a particular contaminant are added to the contaminated soil or water in order to supplement the indigenous microbial population and to accelerate degradation of target compoundsIntrinsic bioremediation – natural attenuation, occurs naturally, requires close monitoring of contaminant degradation to ensure that environment and human health are protected

• in situ

• ex situ

In situ Bioremediation Techniques(involves direct treatment at the contaminated site)

BioventingBiospargingPhytoremediationMonitored Natural AttenuationEnhanced BioremediationPermeable Reactive Barriers

A – primary source of contaminationB – pump-and-treat of contaminants from groundwater C - bioreactor, production of biopreparation (inoculum)D - filtration unitE - aplication of a biopreparationF – imbibitional bore (drill-hole)

Ex situ Bioremediation Techniques (after-excavation treatment of the contaminated material

On site and Off site)

CompostingLandfarmingBiopilesBioreactors(slurry phase treatment)Constructed Wetlands A – decontamination area – isolated to prevent

leaching of contaminats B – system of aeration

C – leaching watersD – bioreactor – production of inoculum

E – aplication of inoculum

Air Emissions

Mixing andOxygen Transfer

LeachateControlSystem

Leachate

Air EmissionsControl Systemor Rain Shed

ContaminatedSoil

The Slovakia Project Delayed (has been frozen)Missing Act on Environmental Loads in Slovakia Waste management legislation

SolutionsContinuing in the effort to start Non-Com ProjectAccelerated acceptance of the Act on „Environmentalburdens (loads)“ in accordance with „Principle Polluter Pay“

Non-Com project

POPs Problems in Slovakia

6. Conclusions

• The market offers a number of alternative waste treatment options many of which are ready for application to PCB and obsolete pesticide stockpiles destruction

• The non-combustion approach is more environmentally safe and friendly than incinerators

• More education and promotion are needed to render these technologies competitive with the combustion technologies

Biodegradation

POPs

Bioremediation

Determination of Ecotoxicityand Genotoxicity

Isolation and identification of bacterial PCB–degraders

Bioremediation of sedimentsby autochthonous and

allochthonous bacterial strains and consortiums

Laboratorium of Environmental Biotechnology FCHFT STU

Monitoring of PCB -contaminated areas

cotton wool stopper

glass column

sorbent SILIPOR C18glass frit

Erlenmeyer flask

mediumPCBsmicroorganisms

•Apparatus for monitoring evaporationand biodegradation of PCBs.

•Sorbent SILIPOR – a chemical trap for evaporated PCB congeners.

•The fate of PCB congener: monitored as evaporated amount captured on the sorbent and the amount remaining in the medium and biomass

EvaporationEvaporation and and biodegradationbiodegradation

kev

kd

↑

→

A scheme of the processes determining the fate of PCBs in the bacterial cell suspension.

Distribution of PCBsDistribution of PCBs

State ofPCBmolecules

Evaporated& capturedon sorbent

Free &boundin medium

Partitionedin biomass Degraded

Kineticscheme

Surface area

Amount

PCBfree

PCBbound

A S

ms ma=maf+mab mb md

κev

κi

κo

κd

Kb

BiosorptionEvaporationBiodegradation

2008

2009

NATO Science Series IV: Earth and

Environmental Sciences – Vol. 19.

Springer, The Netherlands, 2006.

2006

AcknowledgementIng. Anton Kočan, PhD., SZUIng. Pavel Hucko, PhD., VÚVHPhDr. Martin Murín, EkotoxPhDr. Alena Pilváňová, Ekotox Bratislava, Slovakia

Thank you for your attention!

katarina.dercova@stuba.skwww.non-combustion.sk