Desalination combined with copper(II) removal in a novel microbial desalination cell

Abstract

A novel four-chamber microbial desalination cell (FMDC) was proposed to treat synthetic Cu(II)-containing wastewater in the cathode chamber and simultaneously desalinate brine or seawater in the desalination chamber. In this study, two anion exchange membranes (AEMs) and one cation exchange membrane (CEM) were used as separators between the four different function chambers of the FMDC. Below a pH value of 3.0, the maximum current density was 2.0A/m2 with the initial Cu2+ concentration of 800mg/L and an external resistance of 10Ω. The copper removal rate, salt removal rate and total desalination rate, all conducted simultaneously, were 94.1±1.2%, 43.9±0.9% and 5.1±0.6mg/h in a batch-fed cycle, respectively. Scanning electron microscope–energy dispersive spectrometer (SEM–EDS) analysis indicated that the Cu(II) was reduced to Cu2O plus Cu, which deposited on the cathode surface. These results suggested a novel approach to remove and recover Cu(II) from Cu(II)-containing wastewater and to desalinate salt water by using an FMDC reactor.