Enhanced flux and selectivity of metals through a dialysis membrane by addition of complexing agents to receiving phase

The transport fluxes of Cu²⁺ and Ni²⁺ from single and binary feed solutions through a dialysis membrane to a receiving solution containing complexing agent were measured at 298K. Two complexing agents, polyethylenimine (PEI) and ethylenediaminetetraacetic acid (EDTA) were selected. Experiments were performed at different feed concentrations of metals (1.5∼34.5mol/m³), receiving concentrations of the complexing agent (0∼25.6mol/m³), and current densities (0∼185A/m²). It was shown that the fluxes and selectivity factors of metal ions were enhanced with increasing concentrations of metals and the complexing agents. In contrast to the absence of applied voltage, the fluxes of metals were significantly increased but the selectivity factor of Cu²⁺ over Ni²⁺ reduced in the presence of electric field.