College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China; Xiong'an Institute of Eco-Environment, Hebei University, Baoding, 071002, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
J Hazard Mater. 2020 Mar 5;385:121615. doi: 10.1016/j.jhazmat.2019.121615. Epub 2019 Nov 5.
Triclocarban (TCC), as the most typical antibacterial agent, is widely discovered in many ecological environment, especially in sludge. However, so far, no studies have reported the effect of TCC exposure on the properties of excess sludge. Therefore, in this study, TCC's toxicities to waste activated sludge (WAS) were analyzed by investigating the variation of physicochemical properties of sludge. It was found that TCC exposure has no effect on sludge pH, while it facilitated organic substances release from sludge, e.g. dissolved organic matter (DOM), protein and polysaccharide, which caused an increase of sludge reduction and changed the structure of functional groups and surface morphology of sludge. Moreover, we explored the effect of TCC on anaerobic digestion of WAS and found methane production was seriously inhibited by TCC. The related mechanism tests had illustrated that TCC exposure did not affect the hydrolysis process, but promoted the acidification and acetogenesis, and importantly inhibited the methanogenesis process. Methanogenic community was further evaluated and observed that the presence of TCC could vary the microbial community of methanogens with the abundance of aceticlastic methanogens increasing and hydrogenotrophic methanogens decreasing. These findings reached in this study would widen the understanding scope for TCC's toxicity to WAS.
三氯卡班（TCC）作为最典型的抗菌剂，广泛存在于许多生态环境中，尤其是在污泥中。然而，迄今为止，尚无研究报道 TCC 暴露对剩余污泥性质的影响。因此，本研究通过考察污泥理化性质的变化，分析了 TCC 对剩余污泥（WAS）的毒性。结果表明，TCC 暴露对污泥 pH 没有影响，但促进了污泥中有机物的释放，如溶解性有机物（DOM）、蛋白质和多糖，导致污泥减量化增加，并改变了污泥的功能基团结构和表面形态。此外，我们还探讨了 TCC 对 WAS 厌氧消化的影响，发现 TCC 严重抑制了甲烷的生成。相关的机制测试表明，TCC 暴露不影响水解过程，但促进了酸化和产乙酸过程，重要的是抑制了产甲烷过程。进一步评估了产甲烷菌群，观察到 TCC 的存在可以改变产甲烷菌的微生物群落，使乙酸营养型产甲烷菌的丰度增加，氢营养型产甲烷菌的丰度减少。本研究的结果将拓宽对 TCC 对 WAS 毒性的认识范围。
