The occurrences and spatial distributions of eight organic ultraviolet absorbents (UVAs) were investigated in surface sediments from Taihu Lake, China. The detection frequencies and concentrations of UVAs in 2016 were...The occurrences and spatial distributions of eight organic ultraviolet absorbents (UVAs) were investigated in surface sediments from Taihu Lake, China. The detection frequencies and concentrations of UVAs in 2016 were significantly higher than those in 2015.2-Ethylhexyl methoxycinnamate and homosalate (HMS) were the predominant UVAs in the sediment samples. The total UVA concentration range in sediment samples was 0.15–85.3 ng/g. The spatial distribution results showed that UVAs were concentrated in the northwest of Taihu Lake. The total organic carbon content may affect the fate of UVAs in sediments. Source analysis and correlation analysis showed that the following compounds had high proportions and significant correlations: 2-ethylhexyl methoxycinnamate, ethylhexyl salicylate, and HMS in 2015;and benzophenone-3, HMS, and benzyl salicylate in 2016. These results indicated the correlated compounds within each year had the same source. Ecological risk assessment results showed that UVAs in sediment from Taihu Lake may present a moderate risk to benthic organisms. The risk quotient of UVAs in 2016 was slightly higher than that in 2015. The seasonal pollution characteristics of UVAs and their comprehensive environmental risks should receive further attention.展开更多
Distribution and removal of chemicals in wastewater treatment plants(WWTPs)have mainly relied on mathematical models.Existing exposure assessment models such as SimpleTreat,STPWIN are based on conventional activated s...Distribution and removal of chemicals in wastewater treatment plants(WWTPs)have mainly relied on mathematical models.Existing exposure assessment models such as SimpleTreat,STPWIN are based on conventional activated sludge processes.There is an urgent need to develop an A^(2)/O-based WWTPs exposure assessment model.Organophosphates(OPEs)have different physical and chemical properties and potential environmental risks.The fate and biodegradation kinetics of three types of OPEs,including alkyl OPEs,chlorinated OPEs and triphenyl ester OPEs,were studied in a laboratory-scale anaerobic/anoxic/aerobic(A^(2)/O)sewage treatment system and batch reactors.The three types of OPEs had different anaerobic,anoxic,and aerobic removal characteristics.A compensation mechanism was found between anaerobic and anoxic/aerobic removal.When the hydraulic retention time decreased from 82 to 20.5 h,the removal efficiencies in the anaerobic unit decreased,while those in the anoxic unit increased;as a result,the total removal efficiencies remained high(>80%)for all OPEs except triphenyl phosphate(65.5%-75.1%).The concept of effective sludge concentration(MLSS eff)was proposed to illustrate the compensation mechanism and calibrate the second-order kinetic equation for predicting pollutant removal in the A^(2)/O system:MLSS eff=k_(en)×MLSS,where ken is a constant related to the influent total organic carbon content(TOC).The influent TOC contents of the anoxic and aerobic units affected the value of MLSS_(eff)and OPEs removal.The results are of great significance for assessing OPEs exposure and predicting exposure to emerging micropollutants in sewage treatment systems.展开更多
基金supported by the Central Scientific Research Projects for Public Welfare Research Institutes(Grant Nos.GYZX240403 and ZX2023QT003)National Natural Science Foundation of China(Grant No.22306130).
文摘The occurrences and spatial distributions of eight organic ultraviolet absorbents (UVAs) were investigated in surface sediments from Taihu Lake, China. The detection frequencies and concentrations of UVAs in 2016 were significantly higher than those in 2015.2-Ethylhexyl methoxycinnamate and homosalate (HMS) were the predominant UVAs in the sediment samples. The total UVA concentration range in sediment samples was 0.15–85.3 ng/g. The spatial distribution results showed that UVAs were concentrated in the northwest of Taihu Lake. The total organic carbon content may affect the fate of UVAs in sediments. Source analysis and correlation analysis showed that the following compounds had high proportions and significant correlations: 2-ethylhexyl methoxycinnamate, ethylhexyl salicylate, and HMS in 2015;and benzophenone-3, HMS, and benzyl salicylate in 2016. These results indicated the correlated compounds within each year had the same source. Ecological risk assessment results showed that UVAs in sediment from Taihu Lake may present a moderate risk to benthic organisms. The risk quotient of UVAs in 2016 was slightly higher than that in 2015. The seasonal pollution characteristics of UVAs and their comprehensive environmental risks should receive further attention.
基金supported by the Research Beidou Plan(Version 2.0)(Talent Project)of Nanjing Polytechnic Institute(NJPI-RC-2022-03)the Central Scientific Research Projects for Public Welfare Research Institutes(ZX2023QT003)the National Key R and D Program of China(2018YFC1801504).
文摘Distribution and removal of chemicals in wastewater treatment plants(WWTPs)have mainly relied on mathematical models.Existing exposure assessment models such as SimpleTreat,STPWIN are based on conventional activated sludge processes.There is an urgent need to develop an A^(2)/O-based WWTPs exposure assessment model.Organophosphates(OPEs)have different physical and chemical properties and potential environmental risks.The fate and biodegradation kinetics of three types of OPEs,including alkyl OPEs,chlorinated OPEs and triphenyl ester OPEs,were studied in a laboratory-scale anaerobic/anoxic/aerobic(A^(2)/O)sewage treatment system and batch reactors.The three types of OPEs had different anaerobic,anoxic,and aerobic removal characteristics.A compensation mechanism was found between anaerobic and anoxic/aerobic removal.When the hydraulic retention time decreased from 82 to 20.5 h,the removal efficiencies in the anaerobic unit decreased,while those in the anoxic unit increased;as a result,the total removal efficiencies remained high(>80%)for all OPEs except triphenyl phosphate(65.5%-75.1%).The concept of effective sludge concentration(MLSS eff)was proposed to illustrate the compensation mechanism and calibrate the second-order kinetic equation for predicting pollutant removal in the A^(2)/O system:MLSS eff=k_(en)×MLSS,where ken is a constant related to the influent total organic carbon content(TOC).The influent TOC contents of the anoxic and aerobic units affected the value of MLSS_(eff)and OPEs removal.The results are of great significance for assessing OPEs exposure and predicting exposure to emerging micropollutants in sewage treatment systems.
