Biological removal of 17a-ethinylestradiol by a nitrifier enrichment culture in a membrane bioreactor

Bart De Gusseme, Benny Pycke, Tom Hennebel, Annabel Marcoen, Siegfried E. Vlaeminck, Herlinde Noppe, Nico Boon, Willy Verstraete, Rob Van Houdt

Research outputpeer-review


Increasing concern about the fate of 17a-ethinylestradiol (EE2) in the environment stimulates the search for alternative methods for wastewater treatment plant (WWTP) effluent polishing. The aim of this study was to establish an innovative and effective biological removal technique for EE2 by means of a nitrifier enrichment culture (NEC) applied in a membrane bioreactor (MBR). In batch incubation tests, the microbial consortium was able to remove EE2 from both a synthetic minimal medium and WWTP effluent. Incubation of the heterotrophic bacteria isolated from the NEC did not result in a significant EE2 removal, indicating the importance of nitrification as driving force in the mechanism. Application of the NEC in a MBR to treat a synthetic influent with an EE2 concentration of 83 ng EE2 L!1 resulted in a removal efficiency of 99%. Simultaneously, complete nitrification was achieved at an optimal ammonium influent concentration of 1.0 mg NH4þ-N L!1. This minimal NH4þ-N input is very advantageous for effluent polishing since the concomitant effluent nitrate concentrations will be low as well and it offers opportunities for the nitrifying MBR as a promising add-on technology for WWTP effluent polishing.
Original languageEnglish
Pages (from-to)2493-2503
JournalWater Research
Issue number9
StatePublished - Feb 2009

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