To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rain...To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound heavy metals, such as Zn, Pb, and Cu. Results show that the wash off behavior of TSS under varying runoff rate condition can be explained by different antecedent dry weather period (ADWP). Contribution of fine fraction (<45 μm) to TSS was generally higher than that of coarse fraction (>45 μm). When the runoff flow increased obviously, a significant contribution of the coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more significant compared with that in the fine fraction. The results will assist in the development of effective control strategies to minimize heavy metals and solids in highway runoff.展开更多
Catalytic ozonation is an effective wastewater purification process.However,the low ozone mass transfer in packed bubble columns leads to low ozone utilization efficiency(OUE),poor organic degradation performance,and ...Catalytic ozonation is an effective wastewater purification process.However,the low ozone mass transfer in packed bubble columns leads to low ozone utilization efficiency(OUE),poor organic degradation performance,and high energy consumption.Therefore,there is an urgent need to develop efficient supported catalysts that can enhancemass transfer and performance.However,the reaction mechanism of the support on ozone mass transfer remains unclear,which hinders the development of catalytic ozonation applications.In this study,lava rocks(LR)-supported catalysts,specifically CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR,were proposed for catalytic ozonation of IBP degradation due to their superior catalytic activity,stability,and high OUE.Addition of CuMn_(2)O_(4)@LR or MnO_(2)–Co_(3)O_(4)@LR increased IBP removal efficiency from 85%to 91%or 88%,and reduced energy consumption from 2.86 to 2.14 kWh/m^(3)or 2.60 kWh/m^(3),respectively.This improvement was attributed to LRsupported catalysts enhancing mass transfer and promoting O3 decomposition to generate•OH and•O_(2)^(−),leading to IBP degradation.Furthermore,this study investigated the effects of ozone dose,supporter sizes,and catalyst components on ozone-liquid mass transfer.The results revealed that the size of the supporter influenced stacked porosity and consequently affected ozone mass transfer.Larger-sized LR(kLa=0.172 min^(−1))exhibited better mass transfer compared to smaller-sized supports.Based on these findings,it was concluded that both CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR are potential catalysts for catalytic ozonation in residual IBP degradation of pharmaceutical wastewater,and LR showed good credibility as a catalyst supporter.Understanding the effects of supporters and active components on ozone mass transfer provides a fundamental principle for designing supported catalysts in catalytic ozonation applications.展开更多
In this study,carbamazepine(CBZ)decay in solution has been studied by coupling electro-coagulation with electro-Fenton(EC-EF)with a novel P-rGO/carbon felt(CF)cathode,aiming to accelerate the in-situ generation of...In this study,carbamazepine(CBZ)decay in solution has been studied by coupling electro-coagulation with electro-Fenton(EC-EF)with a novel P-rGO/carbon felt(CF)cathode,aiming to accelerate the in-situ generation of·OH,instead of adding Fe2+and H2O2.Firstly,the fabri-cated P-rGO and its derived cathode were characterized by XRD,SEM,AFM,XPS and electro-chemical test(EIS,CV and LSV).Secondly,it was confirmed that the performance in removal efficiency and electric energy consumption(EEC)by EC-EF(kobs=0.124 min^(-1),EEC=43.98 kWh/kg CBZ)was better than EF(kobs=0.069 min^(-1),EEC=61.04 kWh/kg CBZ).Then,P-rGO/CF(kobs=0.248 min^(-1),EEC=29.47 kWh/kg CBZ,CE=61.04%)showed the best performance in EC-EF,among all studied heteroatom-doped graphene/CF.This superior performance may be associated with its largest layer spacing and richest C=C,which can promote the electron transfer rate and conductivity of the cathode.Thus,more H2O2 and·OH could be produced to degrade CBZ,and almost 100%CBZ was removed with kobs being 0.337 min^(-1) and the EEC was only 24.18 kWh/kg CBZ,under the optimal conditions(P-rGO loading was 6.0 mg/cm^(2),the current density was 10.0 mA/cm^(2),the gap between electrode was 2.0 cm).Additionally,no matter the influent is acidic,neutral or alkaline,no additional pH adjustment is required for the effluent of EC-EF.At last,an inconsecutive empirical kinetic model was firstly estab-lished to predict the effect of operating parameters on CBZ removal.展开更多
基金Project supported by the National Key Technology R&D Program of China (No. 2006BAK13B04)the Expo Shanghai Sci-Tech Program of Science and Technology Commission of Shanghai (No.06dz05808)the Natural Science Foundation of Jiangxi Province(No. 2007GZH839), China
文摘To investigate the dynamic characteristics of total suspended solids (TSS) and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound heavy metals, such as Zn, Pb, and Cu. Results show that the wash off behavior of TSS under varying runoff rate condition can be explained by different antecedent dry weather period (ADWP). Contribution of fine fraction (<45 μm) to TSS was generally higher than that of coarse fraction (>45 μm). When the runoff flow increased obviously, a significant contribution of the coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more significant compared with that in the fine fraction. The results will assist in the development of effective control strategies to minimize heavy metals and solids in highway runoff.
基金supported by the National Key Research and Development Program of China(No.2021YFE0100800)the National Natural Science Foundation of China(Nos.22076012,52100002,52200035,and 51878047)+4 种基金the Beijing Forestry University Outstanding Young Talent Cultivation Project(No.2019JQ03008)the Yangtze River Joint Research Phase II Program(Nos.2022-LHYJ-02-0510-02,and 2022-LHYJ-02-0502-02-06)the Open Project of State Key Laboratory of Urban Water Resources and Environment(No.HC202328)the Fundamental Research Funds for the Central Universities(No.BLX202153)the China Postdoctoral Science Foundation(No.2021M700448).
文摘Catalytic ozonation is an effective wastewater purification process.However,the low ozone mass transfer in packed bubble columns leads to low ozone utilization efficiency(OUE),poor organic degradation performance,and high energy consumption.Therefore,there is an urgent need to develop efficient supported catalysts that can enhancemass transfer and performance.However,the reaction mechanism of the support on ozone mass transfer remains unclear,which hinders the development of catalytic ozonation applications.In this study,lava rocks(LR)-supported catalysts,specifically CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR,were proposed for catalytic ozonation of IBP degradation due to their superior catalytic activity,stability,and high OUE.Addition of CuMn_(2)O_(4)@LR or MnO_(2)–Co_(3)O_(4)@LR increased IBP removal efficiency from 85%to 91%or 88%,and reduced energy consumption from 2.86 to 2.14 kWh/m^(3)or 2.60 kWh/m^(3),respectively.This improvement was attributed to LRsupported catalysts enhancing mass transfer and promoting O3 decomposition to generate•OH and•O_(2)^(−),leading to IBP degradation.Furthermore,this study investigated the effects of ozone dose,supporter sizes,and catalyst components on ozone-liquid mass transfer.The results revealed that the size of the supporter influenced stacked porosity and consequently affected ozone mass transfer.Larger-sized LR(kLa=0.172 min^(−1))exhibited better mass transfer compared to smaller-sized supports.Based on these findings,it was concluded that both CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR are potential catalysts for catalytic ozonation in residual IBP degradation of pharmaceutical wastewater,and LR showed good credibility as a catalyst supporter.Understanding the effects of supporters and active components on ozone mass transfer provides a fundamental principle for designing supported catalysts in catalytic ozonation applications.
基金This work was carried out with the support of the Fundamental Research Funds for the Central Universities(No.2017PT01)the Beijing Natural Science Foundation(No.L182027)+2 种基金the National Key Research and Development Program of China(No.2021YFE0100800)the National Natural Science Foundation of China(Nos.22076012 and 51878047)the Beijing Forestry University Outstanding Young Talent Cultivation Project(No.2019JQ03008).
文摘In this study,carbamazepine(CBZ)decay in solution has been studied by coupling electro-coagulation with electro-Fenton(EC-EF)with a novel P-rGO/carbon felt(CF)cathode,aiming to accelerate the in-situ generation of·OH,instead of adding Fe2+and H2O2.Firstly,the fabri-cated P-rGO and its derived cathode were characterized by XRD,SEM,AFM,XPS and electro-chemical test(EIS,CV and LSV).Secondly,it was confirmed that the performance in removal efficiency and electric energy consumption(EEC)by EC-EF(kobs=0.124 min^(-1),EEC=43.98 kWh/kg CBZ)was better than EF(kobs=0.069 min^(-1),EEC=61.04 kWh/kg CBZ).Then,P-rGO/CF(kobs=0.248 min^(-1),EEC=29.47 kWh/kg CBZ,CE=61.04%)showed the best performance in EC-EF,among all studied heteroatom-doped graphene/CF.This superior performance may be associated with its largest layer spacing and richest C=C,which can promote the electron transfer rate and conductivity of the cathode.Thus,more H2O2 and·OH could be produced to degrade CBZ,and almost 100%CBZ was removed with kobs being 0.337 min^(-1) and the EEC was only 24.18 kWh/kg CBZ,under the optimal conditions(P-rGO loading was 6.0 mg/cm^(2),the current density was 10.0 mA/cm^(2),the gap between electrode was 2.0 cm).Additionally,no matter the influent is acidic,neutral or alkaline,no additional pH adjustment is required for the effluent of EC-EF.At last,an inconsecutive empirical kinetic model was firstly estab-lished to predict the effect of operating parameters on CBZ removal.
