Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China; Tai'an Water Conservancy Bureau, Tai'an 271299, PR China.
Sci Total Environ. 2022 Oct 10;842:156665. doi: 10.1016/j.scitotenv.2022.156665. Epub 2022 Jun 13.
On account of hydrophobic nature, the adsorption process on solids is considered as the major pathway for triclosan (TCS) removal in wastewater treatment plants. In this work, four sludge sources (primary sludge, thickened sludge, dewatered sludge, and anaerobic digested sludge) were collected to evaluate the adsorption performance of TCS. The solid-liquid distribution coefficients of TCS were increased with total solids increasing of primary sludge, thickened sludge, and dewatered sludge, whereas decreased in anaerobic digested sludge. Results further revealed differences in sludge floc sub-structures of TCS adsorption. The residues contained most of adsorbed TCS in all sub-structures, while distinguished in various extracellular polymeric substances (EPS). The major contributor of EPS sub-fractions to TCS adsorption was identified as tightly bound EPS in thickened sludge and soluble EPS in anaerobic digested sludge. Based on the excitation-emission matrix spectra and Fourier infrared spectrum results, the protein-like and humic acid-like substances were closely related to the TCS adsorption, and hydrogen bond, hydrophobic interaction, and electrostatic interaction were considered as the dominant mechanisms. This study comprehensively reveals the effects of sludge sources and sub-structures on TCS adsorption, which improves the understanding of interaction and migration processes between TCS and sludge.
由于疏水性，吸附过程被认为是污水处理厂中三氯生（TCS）去除的主要途径。在这项工作中，收集了四种污泥来源（初沉污泥、浓缩污泥、脱水污泥和厌氧消化污泥）来评估 TCS 的吸附性能。TCS 的固液分配系数随着初沉污泥、浓缩污泥和脱水污泥总固体的增加而增加，而在厌氧消化污泥中则降低。结果进一步揭示了 TCS 吸附中污泥絮体亚结构的差异。残留物中包含了所有亚结构中吸附的大部分 TCS，而在各种细胞外聚合物物质（EPS）中则有所不同。对于 TCS 吸附的 EPS 亚组分的主要贡献者被确定为浓缩污泥中的紧密结合的 EPS 和厌氧消化污泥中的可溶 EPS。基于激发-发射矩阵光谱和傅里叶变换红外光谱结果，发现蛋白质样物质和腐殖酸样物质与 TCS 吸附密切相关，氢键、疏水相互作用和静电相互作用被认为是主要机制。本研究全面揭示了污泥来源和亚结构对 TCS 吸附的影响，从而提高了对 TCS 和污泥之间相互作用和迁移过程的理解。
