The fate of C-radiolabelled diclofenac and 40 treatment of wastewater

摘要

This study aimed at enhancing knowledge on the fate of diclofenac (DF), together with its mainnhuman metabolite 40n-hydroxydiclofenac (40nOHDF), during wastewater treatment by using anlaboratory-scale membrane bioreactor (MBR). The reactor was fed continuously withnnon-radiolabelled diclofenac for a one month period prior to a single pulse of a 14nC-radiolabellednsolution of DF and 40nOHDF. The solution spike contained approximately 25% 40nOHDF and 65% DF,nwhich corresponds to the ratio observed in municipal sewage, as well as traces of two othernmetabolites. The radioactivity was monitored for a total of twelve days in the various output streamsnThe calculation of the complete mass balance in the system demonstrated that the major part of thenradioactivity left the reactor with the permeate (88.7%), while 2.1% was recovered in the excessnsludge. Negligible amounts were recovered in the off-gas traps and on the membranes.nChromatographic analyses of effluent samples, by means of HPLC-MS coupled in parallel to anradiodetector, displayed a different pattern than the one of the spiked solution. It showed thenoccurrence of three additional metabolites.