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2L - Immunotoxicity - genotoxicity - ED (WEP/127) Estrogenic activity in waste waters of different origins before and after treatment with advanced methods. Coors, Anja1, Jones, Paul2, Giesy, John2, Ratte, Hans Toni1, 1 Aachen University, Aachen, Germany2 Michigan State University, East Lansing, USA, Michigan ABSTRACT- Effluents of waste water treatment plants (WWTPs) are presumably the main source of xenoestrogens in the aquatic environment. Recently published studies have reported that the elimination of xenoestrogens in WWTPs depends on the treatment technology. In this study we investigated the removal of estrogenic activity by membrane-based waste water treatment and, in comparison, by more conventional methods employing activated sludge treatment and subsequent filtration. The treatment using membranes allows to maintain a higher concentration of biologically active sludge in the aeration tanks, compared to conventional methods, and to retain slowly growing specialized bacteria in the system, which may in turn be more advantageous with regard to the elimination of xenoestrogens. Several grab and composite samples of influents, effluents, and at steps within the treatment processes were taken and tested for estrogenic activity. Filtrates of influent samples and all other samples were concentrated by solid phase extraction, whereas suspended solids of influent samples were separately extracted by Soxhlet extraction. All extracts and dilutions were assessed for estrogenicity with a reportergene-based bioassay using human breastcancer cells (MVLN-cells). The untreated waste water originated from different sources (relation of industrial and domestic sewage as well as landfill leachate) and differed in initial estrogenicity. The treated waste water showed in all cases a much lower level of estrogenic activity compared to the respective raw waste water. However, significant estrogenic activity was still present in some effluents. Key words: xenoestrogens, waste water, estrogen activity, membrane |
