Department of Chemistry, University of Girona, Campus Montilivi, E-17071 Girona, Spain.
Chemosphere. 2012 Aug;88(10):1257-64. doi: 10.1016/j.chemosphere.2012.04.004. Epub 2012 May 2.
Microcosm wetland systems (5 L containers) planted with Salvinia molesta, Lemna minor, Ceratophyllum demersum, and Elodea canadensis were investigated for the removal of diclofenac, triclosan, naproxen, ibuprofen, caffeine, clofibric acid and MCPA. After 38 days of incubation, 40-99% of triclosan, diclofenac, and naproxen were removed from the planted and unplanted reactors. In covered control reactors no removal was observed. Caffeine and ibuprofen were removed from 40% to 80% in planted reactors whereas removals in control reactors were much lower (2-30%). Removal of clofibric acid and MCPA were negligible in both planted and unplanted reactors. The findings suggested that triclosan, diclofenac, and naproxen were removed predominantly by photodegradation, whereas caffeine and naproxen were removed by biodegradation and/or plant uptake. Pseudo-first-order removal rate constants estimated from nonlinear regressions of time series concentration data were used to describe the contaminant removals. Removal rate constants ranged from 0.003 to 0.299 d(-1), with half-lives from 2 to 248 days. The formation of two major degradation products from ibuprofen, carboxy-ibuprofen and hydroxy-ibuprofen, and a photodegradation product from diclofenac, 1-(8-Chlorocarbazolyl)acetic acid, were followed as a function of time. This study emphasizes that plants contribute to the elimination capacity of microcontaminants in wetlands systems through biodegradation and uptake processes.
采用 5 L 容器构建微型湿地系统，种植水鳖、浮萍、金鱼藻和伊乐藻，研究其对双氯芬酸、三氯生、萘普生、布洛芬、咖啡因、氯芬酸和 MCPA 的去除效果。经过 38 天的孵育，种植和未种植反应器中分别有 40%-99%的三氯生、双氯芬酸和萘普生被去除。在有盖对照反应器中，未观察到去除效果。种植反应器中，咖啡因和布洛芬的去除率为 40%-80%，而对照反应器中的去除率则低得多（2%-30%）。在种植和未种植反应器中，氯芬酸和 MCPA 的去除可忽略不计。研究结果表明，三氯生、双氯芬酸和萘普生主要通过光降解去除，而咖啡因和萘普生则通过生物降解和/或植物吸收去除。从时间序列浓度数据的非线性回归中估算得到的拟一级去除速率常数，用于描述污染物的去除情况。去除速率常数范围为 0.003-0.299 d(-1)，半衰期为 2-248 天。作为时间的函数，跟踪了布洛芬的两个主要降解产物，即羧基布洛芬和羟基布洛芬，以及双氯芬酸的光降解产物，1-(8-氯咔唑基)乙酸的形成情况。本研究强调，植物通过生物降解和吸收过程为湿地系统中微污染物的消除能力做出贡献。
