Separation of mixed salts (Cl−/SO42−) by ED based on monovalent anion selective membranes

The industrial products or wastewater rich in the mixed salts (Cl−/SO42−) not only causes the environmental damage, but also induces waste of resource. In this study, an ED stack with monovalent selective AEMs and conventional CEMs was employed to separate the Cl− and SO42− from simulated wastewater. The effect of current density and mass fraction percentage was investigated in order to optimize the experimental conditions during ED process. It was found that at a concentration ratio between NaCl and Na2SO4 of 95/5 (wt%/wt%) and a current density of 40 mA·cm−2, a current efficiency of 72%, an energy consumption of 1.6 kW·h·kg−1 NaCl and a Cl−/SO42− concentration (67.5/3.5 g·L−1) were obtained. Hence, it is appropriate and effective to separate Cl− and SO42− by ED using the monovalent selective AEMs.