University of Oulu

T. Leiviskä, S. Risteelä, Analysis of pharmaceuticals, hormones and bacterial communities in a municipal wastewater treatment plant – Comparison of parallel full-scale membrane bioreactor and activated sludge systems, Environmental Pollution, Volume 292, Part B, 2022, 118433, ISSN 0269-7491,

Analysis of pharmaceuticals, hormones and bacterial communities in a municipal wastewater treatment plant : comparison of parallel full-scale membrane bioreactor and activated sludge systems

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Author: Leiviskä, T.1; Risteelä, S.2
Organizations: 1University of Oulu, Chemical Process Engineering, P.O. BOX 4300, FI-90014, University of Oulu, Oulu, Finland
2Oulu Waterworks, P.O. BOX 35, FI-90015, City of Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.5 MB)
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Language: English
Published: Elsevier, 2022
Publish Date: 2021-11-05


In this study, the occurrence of pharmaceuticals, hormones and bacterial community structures was studied at a wastewater treatment plant in Finland having two different parallel treatment lines: conventional activated sludge (CAS) treatment with a sedimentation stage, and a membrane bioreactor (MBR). Influent and effluents were sampled seven times over a period of one year. The bacterial communities of the influent samples showed a high degree of similarity, except for the February sample which had substantially lower diversity. There was significant fluctuation in the species richness and diversity of the effluent samples, although both effluents showed a similar trend. A marked decrease in diversity was observed in effluents collected between August and November. The initiation of nitrogen removal as a result of an increase in temperature could explain the changes in microbial community structures. In overall terms, suspended solids, bacteria and total organic matter (COD and BOD) were removed to a greater extent using the MBR, while higher Tot-N, Tot-P and nitrate removal rates were achieved using the CAS treatment. Estrone (E1) concentrations were also consistently at a lower level in the MBR effluents (<0.1–0.68 ng/l) compared to the CAS effluents (1.1–12 ng/l). Due to the high variation in the concentrations of pharmaceuticals, no clear superiority of either process could be demonstrated with certainty. The study highlights the importance of long-term sampling campaigns to detect variations effectively.

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Series: Environmental pollution
ISSN: 0269-7491
ISSN-E: 1873-6424
ISSN-L: 0269-7491
Volume: 292, Part B
Article number: 118433
DOI: 10.1016/j.envpol.2021.118433
Type of Publication: A1 Journal article – refereed
Field of Science: 116 Chemical sciences
218 Environmental engineering
Funding: We wish to acknowledge the Maa- ja vesitekniikan tuki ry. and the Finnish Water Utilities Association (Water Utilities Development Fund) for the funding of the study.
Copyright information: © 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (