Photo-degradation of the antimicrobial ciprofloxacin at high pH: Identification and biodegradability assessment of the primary by-products
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- 作者：Tibiriç ; á ; G. Vasconcelos ; Danielle M. Henriques ; Armin Kö ; nig ; Ayrton F. Martins ; Klaus Kü ; mmerer
- 关键词：Pharmaceuticals ; Photo-process ; Photo-products ; Biodegradability assessment
- 刊名：Chemosphere
- 出版年：2009
- 出版时间：July 2009
- 年：2009
- 卷：76
- 期：4
- 页码：487-493
- 全文大小：363 K
文摘
Photo-treatment for the removal of pharmaceuticals in effluents is a topic currently under discussion. In some countries effluents from hospitals are directly emitted into open ditches without any further treatment and with very little dilution. Under such circumstances photo-degradation in the environment can occur. However, photo-degradation does not necessarily end up with the complete mineralization of a chemical. Therefore, photo-product biodegradability and toxicity against environmental bacteria is of interest. Hospital effluents have often a pH around 9. Therefore, photo-oxidation (150 W medium-pressure Hg-lamp, batch reactor) of ciprofloxacin (CIP) was studied at pH 9. The primary elimination of CIP was monitored and structures of photo-products were assessed by liquid chromatography ion trap mass spectrometry (LC–MS/MS). Five compounds were identified as probable products of photo-defluorination, -decarboxylation and loss of the piperazine moiety. These photo-products were not biodegradable in the Closed Bottle test – OECD 301D. They did not affect Vibrio fisheri in the applied concentrations.