Publication type: Article in scientific journal
Type of review: Peer review (publication)
Title: A tiered procedure for assessing the formation of biotransformation products of pharmaceuticals and biocides during activated sludge treatment
Authors: Kern, Susanne
Baumgartner, Rebekka
Helbling, Damian E.
Hollender, Juliane
Singer, Heinz
Loos, Martin J.
Schwarzenbach, René P.
Fenner, Kathrin
et. al: No
DOI: 10.1039/c0em00238k
Published in: Journal of Environmental Monitoring
Volume(Issue): 12
Issue: 11
Page(s): 2100
Pages to: 2111
Issue Date: Nov-2010
Publisher / Ed. Institution: Royal Society of Chemistry
ISSN: 1464-0325
Language: English
Subjects: Disinfectant; Environmental monitoring; Pharmaceutical preparation; Sewage; Tandem mass spectrometry; Biotransformation
Subject (DDC): 363: Environmental and security problems
660: Chemical engineering
Abstract: Upon partial degradation of polar organic micropollutants during activated sludge treatment, transformation products (TPs) may be formed that enter the aquatic environment in the treated effluent. However, TPs are rarely considered in prospective environmental risk assessments of wastewater-relevant compound classes such as pharmaceuticals and biocides. Here, we suggest and evaluate a tiered procedure, which includes a fast initial screening step based on high resolution tandem mass spectrometry (HR-MS/MS) and a subsequent confirmatory quantitative analysis, that should facilitate consideration of TPs formed during activated sludge treatment in the exposure assessment of micropollutants. At the first tier, potential biotransformation product structures of seven pharmaceuticals (atenolol, bezafibrate, ketoprofen, metoprolol, ranitidine, valsartan, and venlafaxine) and one biocide (carbendazim) were assembled using computer-based biotransformation pathway prediction and known human metabolites. These target structures were screened for in sludge-seeded batch reactors using HR-MS/MS. The 12 TPs found to form in the batch experiments were then searched for in the effluents of two full-scale, municipal wastewater treatment plants (WWTPs) to confirm the environmental representativeness of this first tier. At the second tier, experiments with the same sludge-seeded batch reactors were carried out to acquire kinetic data for major TPs that were then used as input parameters into a cascaded steady-state completely-stirred tank reactor (CSTR) model for predicting TP effluent concentrations. Predicted effluent concentrations of four parent compounds and their three major TPs were corroborated by comparison to 3-day average influent and secondary effluent mass flows from one municipal WWTP. CSTR model-predicted secondary effluent mass flows agreed within a factor of two with measured mass flows and confidence intervals of predicted and measured mass flows overlapped in all cases. The observed agreement suggests that the combination of batch-determined transformation kinetics with a simple WWTP model may be suitable for estimating aquatic exposure to TPs formed during activated sludge treatment. Overall, we recommend the tiered procedure as a realistic and cost-effective approach to include consideration of TPs of wastewater-relevant compounds into exposure assessment in the context of prospective chemical risk assessment.
Fulltext version: Published version
License (according to publishing contract): Licence according to publishing contract
Departement: Life Sciences and Facility Management
Organisational Unit: Institute of Chemistry and Biotechnology (ICBT)
Appears in collections:Publikationen Life Sciences und Facility Management

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