title: Elucidation of biotransformation of diclofenac and 4'hydroxydiclofenac during biological wastewater treatment.
abstract: This study aimed at gaining knowledge on the degradation pathway during biological treatment of wastewater of diclofenac and 4'-hydroxydiclofenac, its main human metabolite. For that purpose, an aerobic MBR was acclimatised to diclofenac, and the MBR biomass subsequently incubated with (14)C-diclofenac or (14)C-4'hydroxydiclofenac over 25 days. It was demonstrated that diclofenac degradation was much slower and limited than that of 4'-hydroxydiclofenac. Indeed, after 18 days of batch incubation, diclofenac was removed up to 40%, this rate remained stable till the end of the experiment, while 4'-hydroxydiclofenac was completely degraded within nine days. The analyses of supernatant samples have shown that diclofenac degradation led to four transformation products, more polar than the parent compound, one of them being 4'-hydroxydiclofenac. The degradation of 4'-hydroxydiclofenac led to the formation of the same metabolites than those detected during diclofenac degradation. With these results, the hydroxylation of diclofenac to 4'-hydroxydiclofenac was identified as one major bottleneck in diclofenac degradation during biological treatment of wastewater.
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, CH 4132 Muttenz, Switzerland.
authors.forename: Helene
authors.initials: H
authors.lastname: Bouju
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, CH 4132 Muttenz, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Nastold
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
authors.forename: Birgit
authors.initials: B
authors.lastname: Beck
authors.affiliation: Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
authors.forename: Juliane
authors.initials: J
authors.lastname: Hollender
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, CH 4132 Muttenz, Switzerland; School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: Philippe F-X
authors.initials: PF
authors.lastname: Corvini
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, CH 4132 Muttenz, Switzerland. Electronic address: thomas.wintgens@fhnw.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wintgens
mesh_terms: D019149:Bioreactors; D001711:Biotransformation; D004008:Diclofenac / Q000031:analogs & derivatives* / Q000378:metabolism; D008567:Membranes, Artificial; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004008:Diclofenac; D008567:Membranes, Artificial; D062065:Wastewater; D014874:Water Pollutants, Chemical; C108036:4'-hydroxydiclofenac
keywords: 4′-Hydroxydiclofenac; Biotransformation; Diclofenac; Wastewater treatment