Organophosphate flame retardants (OPFR) in municipal wastewater treatment plants

Transcription

1 Organophosphate flame retardants (OPFR) in municipal wastewater treatment plants Prof. Dr.-Ing. Rita Hilliges Wasserwirtschaft und Umwelttechnik University of Applied Science Hochschule Augsburg NIVA Norsk intitutt for vannforskning Norwegian Institute for Water Research

2 Flame retarding mechanism of OPFRs Flame retardants: achieve flammability standard in furniture, plastics, electronic equipment, textiles Appr. 200 different types, classified after major constituents Different mechanisms Skoog, 2010

3 History of flame retardants Polychlorinated biphenyls (PCBs) Banned late 1970ies Toxic effects: endocrine disruption and neurotoxicity Persistent: still found in sediment and aquatic foodweb!

4 Möller et al., 2012 Histroy of flame retardents 1970 Polychlorinated biphenyls (PCBs) Polybrominated diphenyl ethers (PBDEs) hormone-disrupting effects, impaired neuro development Persistent, bioaccumulative, toxic, highly lipophilic 2010 long-range atmospheric transport ubiquitous Banned 2004/2006: PentaBDE, OctaBDE 2008: DecaBDE

5 Histroy of flame retardents 1970 Polychlorinated biphenyls (PCBs) Polybrominated diphenyl ethers (PBDEs) Organophosphate flame retardants (OPFRs) High Production Volume chemicals HPVs Consumption EU (2006): to/a

6 TCEP Organophosphorus esters Known for 150 years as nerve gas and plant protective agent Chlorinated OP: TCEP, TCPP, TDCP mainly used as flame retardant Non-chlorinated OP: TBEP, TEHP, TnBP, TiBP mainly used as plasticizer, hydraulic fluids, flame retardant TCEP: carinogenic phased out, replaced by TCPP TCPP and TDCPP: on 4 th list of priority substances EU commission Suspected: neurotoxic and mutagenic potential Suspected: persistent (at least chlorinated OP) TCPP

7 Möller et al., 2012 OPFRs Pacific and Indian Ocean air

8 OPFRs Pacific and Indian Ocean air global occurence: marginal seas, open oceans and polar regions concentrations up to 2 ng/m³ dominated by TCPP and TCEP (carcirogenous) 1-3 magnitudes higher than typical PBDE concentrations heaviliy emitted into surface waters Suspected sources: WWTPs

9 Screening of WWTPs in Norway Eight municipal WWTPs in south-east Norway p.e. Four WWTPs with chemical treatment only Four WWTPs combined chem./bio. treatment Six WWTPs discharge into marine water OPFRs and other organic pollutants Sludge samples Flow proportional weekly composite samples

10 Sludge samples

11 Sludge samples Sludge samples (ng/g) Median Min Max Other studies PNEC TIBP a / 27-2,700 b 640 TBP b 5,300 TCEP a / b (wet weight) TCPP 2, ,200 18,400 a / 61-1,900 b 1,300-2,200 c (wet weight) DBPhP DPhBP <LoD <LoD <LoD TDCP a / b 330 TBEP 3, ,600 <5.1-1,900 b 810 TPhP , b 95 EHDPP 2, , ,600 b TEHP <LoD <LoD <LoD ToCP 6 <LoD 20.8 TCP , LoD: Limit of Detection a) Bester, 2009 b) Marklund, 2005 c) Bester, 2005

12 Effluent samples

13 Effluent samples Effluent samples (ng/l) Median Min Max Other studies TIBP c TBP 41 <LoD ,100 a ; c TCEP TCPP ,160 DBPhP 0.36 <LoD 4 DPhBP <LoD <LoD <LoD a ; c Mean: 350, Max: 410 b Mean: 3,000, Max: 6,600 b 1, a TDCP 104 <LoD a ; <8-820 c TBEP 158 <LoD 60,000 Mean: 440, Max: 790 b 3,100-30,000 a ; ,000 c TPhP , a ; c EHDPP c TEHP <LoD <LoD 5.6 <1.4 a ToCP <LoD <LoD 14.4 TCP LoD: Limit of Detection a) Marklund, 2005 b) Bester, 2004

14 Effluent samples risk assessment PNEC PEC PEC/PNEC PEC PEC/PNEC Marine ng/l effl., max ng/l Max effl., median ng/l median TIBP 1, TBP 6, TCEP 6,500 (fresh water) TCPP 640,000 (fresh water) TDCP 1, TBEP 1,300 6, TPhP TCP Potential risk to the marine environment! Calculated OPFR discharge WWPT H (550,000 p.e.): 100 kg/a

15 Fate of OPFRs in WWTPs Removal rate % TBEP TiBP TBP TPhP TCEP TCPP TDCP Mechanical Mech.+Chemical Mech.+Biological Mechanical treatment Chemical treatment Biological treatment

16 Fate of OPFRs in WWTPs Tunnel wash water experiements in Norway (Meland et al., 2011) Sedimentation and filteration: peat filter / activated carbon filter activated carbon: median elimination rate 84 % Removal of chlorinated OPFRs > 70 % Promising with regard to activated carbon filtration at WWTPs

17 Per capita esmissions PBDE PBDE: brominated flame retardants (banned) Per capita emissions between 0.01 and 1 µg/day/capita Evenly distributed by population; independent from size / location

18 Per capita esmissions PFCs PFCs: perflourinated compounds High surface activity: hydrophobic and oil repelling Stain resistant fabric protection, water proofing outdoor clothing, non-stick products (e.g. Teflon) Per capita emissions < 5 µg/day/capita Evenly distributed by population; independent from size / location

19 Per capita esmissions OPFRs Per capita emissions up to 245 µg/day/capita Average ratio: 183 Large site-specific variations Used in great variety of products Traffic (road tunnels, airports) / handling of runoff important

20 Conclusions OPFR new flame retardants Concern about ecotoxicological potential High volume chemicals ubiquitous (Arctic!) 1-2 magnitudes higher concentrations than PBDE Screening Norway: TCPP and TBEP dominating in sludge and effluent samples WWTP effluent: 1 to 250 µg/day/capita unevenly emitted by population 100 kg OPFRs /a emitted by Norway s largest WWTP ( p.e.) Potential risk to marine environment (TBEP, TPhP, TCP)

21 Conclusions Removal of OPFRs in WWTPs: Very low removal rates for chlorinated OPFRs Non-chlorinated OPFRs: removal mainly in aeration basins No significant removal during mechanical treatment Activated carbon filtration: successful with road runoff

22 Acknowledgements Norwegian climate and pollution agency Klif - Klima- og Forurensingsdirektoratet: for funding Full title: Occurrence of selected organic micropollutants and silver at wastewater treatment plants in Norway (report No. TA 2784) NILU - Norwegian institute for air research: for analysis of samples You: for your attention!

23 Organophosphate flame retardants (OPFR) in municipal wastewater treatment plants Prof. Dr.-Ing. Rita Hilliges Wasserwirtschaft und Umwelttechnik University of Applied Science Hochschule Augsburg NIVA Norsk intitutt for vannforskning Norwegian Institute for Water Research