Effects of polystyrene nanoplastics on extracellular polymeric substance composition of activated sludge: The role of surface functional groups

摘要

Here we investigated the acute effects (12 h exposure) of three polystyrene nanoplastics (PS NPs, including PS, PS-COOH and PS-NH2) on extracellular polymeric substance (EPS) composition of acti-vated sludge. Three PS NPs exhibited the significant inhibition in total EPS and protein (PRO) production. The functional groups involved in the interactions between PS NPs and EPS were C-(C, H), and those between PS-NH2 NPs and EPS were C=O and O-C-O. In addition, the dewaterability of activated sludge were optimized by three PS NPs, especially PS-NH2 NPs. Three PS NPs caused nonnegligible cellular oxidative stress and cell membrane damage in activated sludge (PS NPs exposure concentration: 100 mg/L). Among them, the cell membrane damage caused by PS-NH2 was the most significant. Overall, the degree of influence on EPS and cytotoxicity of activated sludge varies with the surface functional groups of PS NPs. (C) 2021 Elsevier Ltd. All rights reserved.