Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei, China.
School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China.
Bioresour Technol. 2020 Aug;309:123316. doi: 10.1016/j.biortech.2020.123316. Epub 2020 Apr 6.
In this study, the effect of extracellular polymer substances on the tetracycline removal under hydroxyl aluminium treatment was investigated, and the molecular mechanisms of extracellular polymeric substances mediated coagulation of tetracycline were also explored. The results show that the presence of extracellular polymeric substances could significantly enhance the removal efficiency of tetracycline in hydroxyl aluminium coagulation. Findings suggest that tyrosine and tryptophan in extracellular proteins acted as binding sites to capture tetracycline. Evidences provided by the density functional theory calculations in combination with spectroscopy analysis indicated that two main mechanisms accounted for tetracycline removal in the presence of extracellular polymeric substances and polyaluminum chloride: (1) amino group in proteins and carbonyl in tetracycline were bridged by Al; (2) benzene rings in tryptophan and tyrosine were π-π stacked with tetracycline, and the amino group in complexes were further coordinated with Al.
在这项研究中，考察了胞外聚合物物质对羟基铝处理下四环素去除的影响，并探讨了胞外聚合物物质介导的四环素凝聚的分子机制。结果表明，胞外聚合物物质的存在可以显著提高羟基铝混凝过程中四环素的去除效率。研究结果表明，胞外蛋白质中的酪氨酸和色氨酸作为结合位点来捕获四环素。密度泛函理论计算与光谱分析提供的证据表明，在存在胞外聚合物物质和聚合氯化铝的情况下，有两种主要的机制可以去除四环素：（1）蛋白质中的氨基基团和四环素中的羰基通过 Al 桥接；（2）色氨酸和酪氨酸中的苯环与四环素发生π-π堆积，配合物中的氨基基团进一步与 Al 配位。
