Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China.
Department of Chemistry, Fudan University, Shanghai, 200433, PR China.
Chemosphere. 2022 Nov;307(Pt 2):135826. doi: 10.1016/j.chemosphere.2022.135826. Epub 2022 Aug 7.
Surface water contains a large amount of dissolved organic matter (DOM). Interactions between DOM and micropollutants have a significant impact on micropollutant degradation. In this study, algal extracellular polymeric substances (EPS) and natural organic matter (NOM) were selected as two DOM sources and oxytetracycline (OTC) as a representative micropollutant. EPS was mainly composed of tryptophan and protein-like organics, while NOM was mainly composed of fulvic acid-like, humic acid-like, and hydrophobic acid components. In addition, OTC degradation significantly decreased when bound with EPS and the C=O and C-H bonds of CH or CH groups may be involved in binding EPS and OTC, respectively, while -COOH may be involved in the binding of NOM and OTC. Furthermore, triplet intermediates were found to play a major role in OTC photodegradation in both EPS and NOM, with the contribution calculated as 49.96% and 44.61%, respectively. Steady-state concentrations of EPS* in EPS and NOM* in NOM were 3.59 × 10 mol L and 5.54 × 10 mol L, respectively. These results provide new insights into the degradation of antibiotic-containing wastewater in the natural environment or engineering applications.
地表水含有大量的溶解有机物质（DOM）。DOM 与微量污染物之间的相互作用对微量污染物的降解有重大影响。在这项研究中，选择藻细胞外聚合物（EPS）和天然有机物质（NOM）作为两种 DOM 来源，以土霉素（OTC）作为代表微量污染物。EPS 主要由色氨酸和蛋白类有机物组成，而 NOM 主要由富里酸类、腐殖酸类和疏水性酸组成。此外，当与 EPS 结合时，OTC 的降解显著降低，并且 CH 或 CH 基团的 C=O 和 C-H 键可能分别参与结合 EPS 和 OTC，而 -COOH 可能参与 NOM 和 OTC 的结合。此外，在 EPS 和 NOM 中，三重态中间体在 OTC 光降解中起主要作用，其贡献分别计算为 49.96%和 44.61%。EPS 中的 EPS和 NOM 中的 NOM的稳态浓度分别为 3.59×10-6 mol L 和 5.54×10-6 mol L。这些结果为在自然环境或工程应用中降解含抗生素废水提供了新的见解。
