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论文类型：期刊论文

发表时间：2017-11-15

发表刊物：CHEMICAL ENGINEERING JOURNAL

收录刊物：SCIE、EI

卷号：328

页面范围：293-303

ISSN号：1385-8947

关键字：Electrochemically switched ion permselectivity; BPEI-CQD/PPy/PSS membrane; Cu2+ separation; Sorption-diffusion

摘要：The continuous separation of dilute Cu2+ from wastewater was performed by using a branched poly (ethylenimine) (BPEI)-functionalized carbon quantum dots (BPEI-CQD)/polypyrrole (PPy)/polystyrene-sulfonate (PSS) membrane in an electrochemically switched ion permselective (ESIP) process. The membrane with a high selectivity for Cu2+ separation was prepared by pressure filtering BPEI-CQD/PPy/PSS solution through a polytetrafluoroethylene (PTFE) membrane. In this ESIP system, the directional uptake/release of Cu2+ was realized by modulating the redox state of the membrane coupling with an external electric field. The effects of the operating parameters on the flux of Cu2+ and membrane permselectivity were investigated. The BPEI-CQD/PPy/PSS composite electrode showed excellent permselectivity for Cu2+ with a flux of 0.108 mg . cm (2) . h (1), a current efficiency of 39.9% and an excellent cycling stability. The Cu2+ concentration in the solution was reduced from 30 to 0.82 ppm with a removal efficiency of 97.2%. Furthermore, the effects of BPEI-CQD content and the membrane thickness on the separation properties of the membrane from a mixed nitrate solution containing Cu2+, Ni2+ and Cd2+ were investigated. It is expected to understand the sorption-diffusion mechanism of such a membrane and provide more information on the design of it for a practical metal ion separation process. (C) 2017 Elsevier B.V. All rights reserved.