Department of Civil and Environmental Engineering, University of Nevada, Reno, NV 89557, USA.
Environ Sci Process Impacts. 2017 Apr 19;19(4):499-506. doi: 10.1039/c7em00003k.
Triclosan (TCS), one of the most widely used antimicrobial agents, has been listed among the top 10 contaminants in US rivers. Environmental persistence, endocrine disruption effects, and the antibiotic resistance induction capacity of TCS attract interest in its environmental fate and degradation. Herein, we found that TCS can be anaerobically degraded at pH 9 by a metal-reducing bacterium, Shewanella putrefaciens CN32. The degradation was substantially facilitated by low-concentration (0-15 mg C per L) organic matter (OM) extracted from a peat soil, whereas TCS degradation was inhibited by further increased concentration (15-100 mg C per L) of OM. OM acted as both an electron shuttle and sorbent in regulating the degradation of TCS. The novel dual role of ubiquitous OM in the reaction of TCS governs the environmental degradation and persistence of TCS. Our study highlights the effects of OM on the reaction of emerging trace organic pollutants, with implications on their engineering treatment and environmental risk regulation.
三氯生（TCS）是应用最广泛的抗菌剂之一，已被列入美国河流中排名前十的污染物。由于 TCS 具有环境持久性、内分泌干扰效应和诱导抗生素抗性的能力，因此人们对其环境归宿和降解情况很感兴趣。本研究发现，在 pH 值为 9 的条件下，金属还原菌希瓦氏菌（Shewanella putrefaciens）CN32 可以将 TCS 进行厌氧降解。低浓度（0-15mgC/L）的泥炭土中提取的有机物（OM）极大地促进了 TCS 的降解，而当 OM 浓度进一步增加（15-100mgC/L）时，TCS 的降解则受到抑制。OM 既作为电子穿梭体又作为吸附剂在调节 TCS 降解中发挥作用。普遍存在的 OM 在 TCS 反应中的这种双重作用决定了 TCS 的环境降解和持久性。本研究强调了 OM 对新兴痕量有机污染物反应的影响，这对其工程处理和环境风险调控具有重要意义。
