The response and anti-stress mechanisms of nitrifying sludge under long-term exposure to Cd Se quantum dots

作     者：Linkai Guo Lei Yang Yongxiang Ren Shen Cui Xiaotong Li Jia Wang Jun Lan Haoqi Lu Yuchao Wang 

作者机构：Shaanxi Key Laboratory of Environmental EngineeringXi’an University of Architecture and TechnologyXi’an 710055China Key Lab of Northwest Water ResourceEnvironment and EcologyMinistry of EducationXi’an University of Architecture and TechnologyXi’an 710055China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2024年第135卷第1期

页      面：174-184页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：supported by the Special Scientific Research Program of Shaanxi Provincial Education Department (No.21JK0716) the Natural Science Basic Research Project of Shaanxi Province (No.2022JM-217) the National Natural Science Foundation of China (No.51878537) 

主　　题：Quantum dots Activated sludge Extracellular polymeric substances Microbial community Antioxidant effect 

摘      要：The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment *** study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrifying sludge under long-term exposure to CdSe *** showed CdSe QDs(≥1 mg/L)would decrease the activity of ammonia monooxygenase(AMO).Under the stress of 30 mg/L CdSe QDs,the activity of AMO was reduced by 66%,while the activities of hydroxylamine oxidase and nitrite oxidoreductase were enhanced by 19.1%and 26%,***,the final nitrification effects were not adversely affected,and the production rates of NO_(2)^(-)-N and NO_(3)^(-)-N were ***,CdSe QDs improved biomass concentration in sludge and maintained the stability of sludge *** throughput sequencing analysis showed that CdSe QDs evidently reduced the abundance and diversity of microbial community in nitrifying *** abundances of amino acid metabolism and lipid metabolism were ***,CdSe QDs decreased the fluorescence intensity of tryptophan-like protein from 2,326 to 1,179 *** loosely bound extracellular polymeric substances(EPSs)and from 3,792 to 3,117 *** tightly bound *** relieve CdSe QD stress,the polysaccharide content increased from0.31 to 0.61 mg/g MLSS and intracellular antioxidant defense was *** CdSe QD level increasing to 30 mg/L,the total antioxygenic capacity and the activities of catalase were enhanced up to 411%and 143.2%,***,CdSe QDs had little adverse effects on cell membrane integrity,microbial metabolism and the abundance of Nitrospirae.