Kurzbeschreibung
(Englisch)
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The general goal of the project is to assess the input of biocides into the aquatic environment and to investigate the efficiency of conventional treatment as well as of advanced oxidation in WWTPs for the elimination of biocides. The project focuses on: i) mass flux studies in wastewater treatment plants (WWTP) to reveal the importance of urban sources of bio-cides input into ambient waters; ii) the evaluation of the success of an additional ozonation step for the elimination of se-lected hydrophilic biocides within a full-scale WWTP; iii) the screening for stable transformation products originating from ozonation using a hybrid system of linear ion trap combined with the new orbitrap technology; iv), the contribution of the WWTP effluent, the combined sewer overflow and the inputs from the agriculture to the overall pollution of the receiving water by mass flux analysis during rain events.
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Partner und Internationale Organisationen
(Englisch)
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AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GR, HR, IE, IL, IT, LT, LU, LV, MK, NL, NO, PL, PT, RO, RS, SE, SI, TR, UK
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Abstract
(Englisch)
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The general goal of the project was to assess the input of biocides into the aquatic environment and to investigate the efficiency of conventional treatment as well as of advanced oxidation in a wastewater treatment plants (WWTP) for the elimination of biocides. The project focused on: i) mass flux studies in a WWTP to reveal the importance of urban sources of biocides input into ambient waters; ii) the evaluation of the success of an additional ozonation step for the elimination of selected hydrophilic biocides within a full-scale WWTP; and iii), the contribution of the WWTP effluent and the inputs from the agriculture to the overall pollution of the receiving water by mass flux analysis during rain events. For the simultaneous determination of the polar contaminants present at trace concentrations an analytical method with a high sample throughput was necessary. Therefore, a fully automated on-line solid phase extraction method coupled to liquid chromatography and tandem mass spectrometry using positive and negative electrospray ionization was developed and validated. Mass flux studies were performed at the municipal wastewater treatment plant in Regensdorf in the Canton of Zurich. Biocide concentrations in the influent and effluent of the WWTP were usually below 100 ng/L, except for mecoprop with concentrations above 1 µg/L in the influent as well in the effluent. The treatment process of the conventional WWTP was not sufficient to remove most of the biocides. Removal of carbendazim, diazinon, diuron, irgarol 1051, isoproturon, mecoprop, terbutylazine was below 50%. Several biocides which are applied in agriculture and as well in urban settlements, namely carbendazim, diuron, diazinon, and mecoprop, showed significant higher concentrations in the effluent than in the surface water. Diazinon concentrations downstream of the WWTP laid above the threshold value for chronic effects. The assessment of the ozonation as a treatment step was focused on the biocidal compounds that were only partially eliminated during conventional treatment. It could be shown that advanced oxidation with ozone is an efficient removal step for the elimination of several biocidal compounds from wastewater effluents and thus helping to further reduce the loads of micropollutants entering the receiving waters. At a medium level of ozone of 0.62 ± 0.05 g O3/g DOC, ozonation contributed substantially to the elimination of carbendazim (78%), diazinon (67%), diuron (74%), irgarol (89%), isoproturon (97%) and mecoprop (68%). For the triazine derivatives atrazine (25%) and terbutylazine (28%) no substantial elimination was observed.
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