Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, CH 4132 Muttenz, Switzerland.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
J Hazard Mater. 2016 Jan 15;301:443-52. doi: 10.1016/j.jhazmat.2015.08.054. Epub 2015 Aug 29.
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.
本研究旨在了解在废水的生物处理过程中，双氯芬酸及其主要人体代谢物 4'-羟基双氯芬酸的降解途径。为此，采用好氧 MBR 对双氯芬酸进行驯化，然后将 MBR 生物量在 25 天内用 (14)C-双氯芬酸或 (14)C-4'-羟基双氯芬酸孵育。结果表明，双氯芬酸的降解速度比 4'-羟基双氯芬酸慢且有限。事实上，在 18 天的批处理孵育后，双氯芬酸的去除率高达 40%，这一速率一直稳定到实验结束，而 4'-羟基双氯芬酸在九天内被完全降解。对上清液样品的分析表明，双氯芬酸的降解导致了四种转化产物的形成，比母体化合物更具极性，其中一种为 4'-羟基双氯芬酸。4'-羟基双氯芬酸的降解导致了与在双氯芬酸降解过程中检测到的相同代谢物的形成。根据这些结果，将双氯芬酸羟化为 4'-羟基双氯芬酸被确定为废水生物处理过程中双氯芬酸降解的一个主要瓶颈。
