title: Phthalates, nonylphenols and LAS in an alternately operated wastewater treatment plant--fate modelling based on measured concentrations in wastewater and sludge.
abstract: The performance of an alternately operated activated sludge wastewater treatment plant (WWTP) has been investigated with respect to six phthalates, nonylphenol (NP) and nonylphenol diethoxylate (NPDE) and linear alkylbenzene sulphonates (LAS). Samples of raw sewage, primary and secondary sludge and treated water were collected during an 8-day period in May 1999 and analysed for dissolved and sorbed substances. To evaluate the system performance with respect to substance removal through biodegradation and sorption to sludge the measured data were applied in a model describing the different bioreactors as one single reactor, corresponding to the concepts of, e.g. SimpleTreat. The most abundant of the investigated phthalates was di-(2-ethylhexyl)-phthalate (DEHP) with a measured mean inlet flow of 240g/day. Two percent of this amount was found in the treated water, 70% was biodegraded and 28% was found in the sludge. For LAS the mean inlet flow was 20,300g/day, of which less than 1% was found in the treated water, 84% was biodegraded and 15% was found in the sludge. The mean inlet flow of NP and NPDE was 44 and 590g/day, of which 4% and 2% was found in the treated water, 80% was biodegraded for both substances, and 16% and 18% was found in the sludge, respectively. The WWTP removal of the investigated substances was thus high compared to other studies of conventional activated sludge WWTPs. The simple model set-up presents a strong tool for predicting substance removal and system sensitivity related to changes in the inlet conditions, such as concentrations and flow. Furthermore, it allows the inclusion of complex alternately operated WWTPs in risk assessment tools such as e.g. SimpleTreat.
authors.affiliation: Department of Policy Analysis, National Environmental Research Institute, Frederiksborgvej 399, DK-4000, Roskilde, Denmark. paf@dmu.dk
authors.forename: Patrik
authors.initials: P
authors.lastname: Fauser
authors.forename: Jørgen
authors.initials: J
authors.lastname: Vikelsøe
authors.forename: Peter B
authors.initials: PB
authors.lastname: Sørensen
authors.forename: Lars
authors.initials: L
authors.lastname: Carlsen
mesh_terms: D017738:Alkanesulfonic Acids / Q000032:analysis* / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D008962:Models, Theoretical; D010636:Phenols / Q000032:analysis* / Q000378:metabolism; D010795:Phthalic Acids / Q000032:analysis* / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D013501:Surface-Active Agents / Q000032:analysis* / Q000378:metabolism; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism
chemical_list: D017738:Alkanesulfonic Acids; D010636:Phenols; D010795:Phthalic Acids; D012722:Sewage; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C030641:alkylbenzyl sulfonic acid; C025256:nonylphenol