Nanofiltration(NF)has attracted increasing attention for wastewater treatment and potable water purification.However,the high-efficiency removal of micropollutants by NF membranes is a critical challenge.Owing to the ...Nanofiltration(NF)has attracted increasing attention for wastewater treatment and potable water purification.However,the high-efficiency removal of micropollutants by NF membranes is a critical challenge.Owing to the adsorption and subsequent diffusion,some weakly charged or uncharged micropollutants,such as bisphenol A(BPA),can pass through NF membranes,resulting in low removal rates.Herein,an effective strategy is proposed to enhance the BPA removal efficiency of a crosslinked polyaniline/carbon nanotube NF membrane by coupling the membrane with electro-assistance.The membrane exhibited a 31.9%removal rate for 5 mg/L BPA with a permeance of 6.8 L/(m2·h·bar),while the removal rate was significantly improved to 98.1%after applying a voltage of 2.0 V to the membrane.Furthermore,when BPA coexisted with humic acid,the membrane maintained 94%removal of total organic carbon and nearly 100%removal of BPA at 2.0 V over the entire filtration period.Compared to continuous voltage applied to the membrane,an intermittent voltage(2.0 V for 0.5 h with an interval of 3.5 h)could achieve comparable BPA removal efficiency,because of the combined effect of membrane adsorption and subsequent electrochemical oxidation.Density functional theory calculations and BPA oxidation process analyses suggested that BPA was adsorbed by two main interactions:π–πand hydrogen-bond interactions.The adsorbed BPA was further electro-degraded into small organic acids or mineralized to CO_(2) and H2O.This work demonstrates that NF membranes coupled with electro-assistance are feasible for improving the removal of weakly charged or uncharged micropollutants.展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2020YFA0211001)the National Natural Science Foundation of China(Nos.22106017 and 52100074)+1 种基金the China Postdoctoral Science Foundationn(No.2022M710583)the Programme of Introducing Talents of Discipline to Universities(China)(No.B13012).
文摘Nanofiltration(NF)has attracted increasing attention for wastewater treatment and potable water purification.However,the high-efficiency removal of micropollutants by NF membranes is a critical challenge.Owing to the adsorption and subsequent diffusion,some weakly charged or uncharged micropollutants,such as bisphenol A(BPA),can pass through NF membranes,resulting in low removal rates.Herein,an effective strategy is proposed to enhance the BPA removal efficiency of a crosslinked polyaniline/carbon nanotube NF membrane by coupling the membrane with electro-assistance.The membrane exhibited a 31.9%removal rate for 5 mg/L BPA with a permeance of 6.8 L/(m2·h·bar),while the removal rate was significantly improved to 98.1%after applying a voltage of 2.0 V to the membrane.Furthermore,when BPA coexisted with humic acid,the membrane maintained 94%removal of total organic carbon and nearly 100%removal of BPA at 2.0 V over the entire filtration period.Compared to continuous voltage applied to the membrane,an intermittent voltage(2.0 V for 0.5 h with an interval of 3.5 h)could achieve comparable BPA removal efficiency,because of the combined effect of membrane adsorption and subsequent electrochemical oxidation.Density functional theory calculations and BPA oxidation process analyses suggested that BPA was adsorbed by two main interactions:π–πand hydrogen-bond interactions.The adsorbed BPA was further electro-degraded into small organic acids or mineralized to CO_(2) and H2O.This work demonstrates that NF membranes coupled with electro-assistance are feasible for improving the removal of weakly charged or uncharged micropollutants.
