Biodegradation of persistent polar pollutants in wastewater: comparison of an optimised lab-scale membrane bioreactor and activated sludge treatment

Transcription

1 Biodegradation of persistent polar pollutants in wastewater: comparison of an optimised lab-scale membrane bioreactor and activated sludge treatment Marco Bernhard,, Jutta Müller, Thomas P. Knepper Workshop Mitigation Technologies November 27-28, 28, 2007, Aachen, Germany

2 verview I. P-THREE II. III. IV. WWTP Wiesbaden & membrane bioreactor Analysis & statistics Monitoring & degradation results V. Conclusions

3 I. P-THREE

4 P-THREE Removal of Persistent Polar Pollutants Through Improved Treatment of Wastewater Effluents EU-Project (EVK1-CT ) Persistent Polar Pollutants (P 3 ) Development of analytical methods Monitoring

5 Persistent Polar Pollutants: Entry in the watercycle via wastewater treatment plants (WWTP) household agriculture water works wastewater industry indirect discharge groundwater WWTP bankfiltration polluted rivers

6 Selection criteria for P 3 Poorly biodegradable during wastewater treatment and polar, thus per definition relevant for waterworks and drinking water. Detected in surface water and ground water during monitoring campaigns. Significant production rates. Some already listed in priority lists of EU.

7 Selected analytes of P-THREE H C H H C H Cl Cl NH Clofibric Acid Cl Diclofenac Ibuprofen S 3 Sulfophenylcarboxylates [SPCs] H Cl NH 2 C N C CH 2 CH 2 CH 2 H n Nonylphenolethoxycarboxylates [NPECs] Cl 2,4-Dichlorobenzoic Acid [DCBA] Carbamazepine Cl H 3 C H C H N S N CH 3 C H H C N N EDTA C H H C CH 3 MCPP Cl CH 3 MCPA H C CH 3 Bentazone

8 P 3 compounds in European wastewater effluents 1-10 µg L -1 log c [µg L -1 ] µg L µg L -1 DICL CARB IBU DCBA CLFI Reemtsma,T., Weiss, S., Mueller, J., Petrovic, M., González,S., Barcelo, D., Ventura, F., Knepper, T.P.; Environ.Sci.Technol., 2006.

9 P 3 : Reduced entry into the watercycle via an enhanced WWT? household agriculture water works wastewater industry indirect discharge groundwater WWTP MBR/AP bankfiltration rivers Future aspects: Production of Drinking water exclusively with natural methods

10 II. WWTP Wiesbaden and membrane bioreactor

11 WWTP Wiesbaden and MBR PE HRT (h) SRT (d) CD in (mg/l) industr. (%) CAS tert. chem-p 28x MBR 7;

12 Design of lab-scale MBR Reactor» 22 L aerated volume Membranes» Kubota plate modul» surface 0.3 m 2» nominal pore size 0.4 µm Primary treated effluent as feed

13 Removal of polar pollutants in MBR, operation and sampling MBR expected to be superior to activated sludge treatment (AST)» at lower hydraulic retention time (HRT) Why?» higher sludge retention time (SRT) = sludge age» need for slowly growing specialists - adaptation peration» MBR operated for about 2 years» single stage biological treatment Sampling» 24h mixed samples of MBR influent and efluent, WWTP effluent» sampling corrected for HRT of WWTP and MBR» once (or twice) a week» about 80 samplings in two years of MBR operation

14 III. Analysis & statistics

15 Analytical determination of P 3 and their metabolites Complex matrices Low detection limits Selective/sensitive analytical methods Time and labour consuming procedures Extraction clean-up Filtration, solid phase extraction with various materials, derivatisation Separation HPLC GC IC Detection ESI-MS/MS EI quadrupole or ion trap MS ESI-Q-TF-MS Identification of P 3, their metabolites and degradation products via mass spectra and library searches (GC/MS). Quality assurance via interlab test.

16 Method validation (n=5) Bernhard, M., Müller, J., Knepper, T.P.; Wat. Res., 2006.

17 IV. Monitoring and degradation results

18 Sludge concentration & SRT of the MBR 30 sludge retention time Sludge concentration [g L -1 ] Sludge retention time [d] sludge concentration HRT 10 h HRT 7 h Bernhard, M., Müller, J., Knepper, T.P.; Wat. Res., 2006.

19 Removal of Diclofenac 100 MBR-effluent WWTP-effluent 0, SRT 230 d SRT 260 d SRT 308 d SRT 322 d SRT 337 d SRT 347 d SRT 363 d SRT 376 d SRT 386 d SRT 398 d SRT 411 d Elimination Removal [%] HRT 10 h HRT 7 h No adsorption to sludge! Bernhard, M., Müller, J., Knepper, T.P.; Wat. Res., 2006.

20 Removal of Ibuprofen 96,0 99,3 99,5 99,1 98,4 99,1 98,4 99,0 96,8 97,4 98,4 98,4 96,9 96,9 95,6 95,3 97,0 99,0 99,1 98,7 99,1 99, MBR-effluent WWTP-effluent SRT 230 d SRT 260 d SRT 308 d SRT 322 d Elimination Removal [%] [%] SRT 337 d SRT 347 d SRT 363 d SRT 376 d SRT 386 d SRT 398 d SRT 411 d HRT 10 h HRT 7 h

21 Concentrations of Clofibric Acid < LD < LD < LD < LD < LD < LD < LD < LD < LD 0,08 0,08 0,08 0,10 0,10 0,10 0,10 0,10 0,10 0,10 0,09 0,10 0,05 0,10 0,05 0,07 0,06 0,06 0,05 0,08 0,06 0,15 0,15 0,14 0,18 0,16 0,14 WWTP-influent MBR-influent MBR-effluent WWTP-effluent 0,12 0,10 0,08 0,06 0,04 0,02 0, SRT 230 d SRT 260 d SRT 308 d SRT 322 d SRT 337 d SRT 347 d SRT 363 d SRT 376 d SRT 386 d SRT 398 d SRT 411 d c [µg L -1 ] HRT 10 h HRT 7 h MBR-effluent: no significant removals were calculated due to concentrations < LD.

22 Removal of Dichlorobenzoic Acid MBR-effluent WWTP-effluent 98,6 92,9 83,3 91,7 94,4 94,4 90,9 95,5 85,7 92,9 87,5 87,5 75,0 75,0 100,0 50,0 56,3 44,3 61,3 47,9 59,3 36, SRT 230 d SRT 260 d SRT 308 d SRT 322 d SRT 337 d SRT 347 d SRT 363 d SRT 376 d SRT 386 d SRT 398 d SRT 411 d Removal Elimination [%] [%] HRT 10 h HRT 7 h

23 Concentrations of Carbamazepine 0,80 0,81 1,25 1,09 1,35 1,24 1,19 1,25 1,15 1,38 1,30 1,33 1,46 1,17 1,41 1,24 1,17 1,17 1,60 1,40 1,20 WWTP-influent MBR-influent MBR-effluent W W T P -effluent 1,00 0,80 0,60 0,40 0,20 0, SRT 351 d SRT 363 d SRT 376 d SRT 386 d SRT 398 d SRT 411 d c [µg L -1 ] HRT 7 h

24 Summary of removals of pharmaceuticals Average load WWTP Average Average load MBR Average Compound Wiesbaden [µg m -3 d -1 ] influent a effluent removal WWTP [%] [µg m -3 d -1 ] influent a effluent removal MBR [%] rapid biodegradable compounds in WWTP and MBR Ibuprofen 6810± ± ± ± ,4-Dichlorobenzoic acid 452±308 87± ±326 78±44 83 poorly biodegradable compounds in WWTP, rapid biodegradable compounds in MBR Diclofenac 2133± ± ± ± Clofibric acid 96±27 71± ±17 42±35 b 54 poorly biodegradable compounds in WWTP and MBR Carbamazepine 1273± ± ± ± a after primary settlement b concentrations < LD were set to half the LD Bernhard et al., Wat. Res., 2006.

25 Comparison of removals in WWTP Wiesbaden, lab-scale and real MBR mean value (Erftverband n=2-5, Wiesbaden n=12-15) MBR MBR lab-scale pilot - Wiesbaden - Wiesbaden MBR MBR full-scale fullscale - Erftverband - WWTP CAS --Wiesbaden 80 Removal [%] Diclofenac x Carbamazepine

26 Influence of increasing SRT on removal by MBR Removal [%] Bayrepel-acid DEET Diclofenac Carbamazepine Bernhard, M., Müller, J., Knepper, T.P.; Wat. Res., SRT [d]

27 V. Conclusions Following an ambient adaptation time and exceeding threshold values the elimination rates of some P 3 by MBR are higher compared to AST. Non-eliminable pharmaceuticals persist in the environment. But, never a complete removal could be achieved even when the SRT exceeded 400 d. The reduction of the HRT from 10 to 7h did not affect the removals. A further reduction can be achieved by AP, e.g. ozonization or electron beam irradiation. MBR technology TDAY is cost intensive (energy) thus it can only be recommended for remote places and treatment of highly polluted wastewater. Even if the P 3 concentrations are quite low and in spite of low toxicity, a reduction should be achieved, since the procedure for eliminating the P 3 substances during drinking water treatment is complicated and cost intensive.

28 Acknowledgement Funding by European Union for the projects Removal of Persistent Polar Pollutants through Improved Treatment of Wastewater Effluents (P-THREE; EVK1-CT ) is gratefully acknowledged. We thank the ESWE Innovation Fund for financial support. And, of course, I thank you for your attention!

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