A three-dimensional (3D) polypyrrole (PPy)@graphene oxide (GO) composite membrane was developed for the continuous separation of dilute Pb2+ from wastewater in a novel potential-controlled ion pump system based on an electrochemically switched ion permselectivity (ESIP) method. The 3D PPy@GO composite membrane was fabricated via a simple one-step electrochemical co-deposition way in an aqueous electrolyte solution using a stainless steel wire mesh (SSWM) as the conductive substrate. In this system, the directional uptake/release of Pb2+ was realized by modulating the redox state of the PPy@GO membrane and coupling it with an external electric field. The coupling of the pulse potential and cell potential formed a novel potential-controlled ion pump system which controlled the transport of Pb2+. The permselectivity of the 3D PPy@GO membrane and the effects of the cell potential, pulse width, pulse potential and initial concentration on the Pb2+ flux were investigated. The 3D PPy@GO composite coated electrodes showed excellent permselectivity of Pb2+ with a flux of 4.7 g m (2) h (1), a current efficiency of 51.9% and excellent cycling stability. The Pb2+ concentration was reduced from 20 ppm in the source solution to 0.8 ppm with a removal percentage of 96%. This 3D PPy@GO membrane-based ESIP system could be used as a novel technique for wastewater treatment. (C) 2017 Elsevier Ltd. All rights reserved.