Transport of selected transition metal ions across heterogeneous membranes in ED enhanced with complex formation

In this work, the effectiveness of electrodialysis enhanced with complex formation for selective zinc ions removal from simulated zinc electroplating bath contaminated with copper and iron was investigated. The effect of the chelating agent (citric acid) addition and pH of examined solutions were discussed. The selectivity coefficients of iron, copper and zinc ions were determined. Maximum values of selectivity coefficients equaled to 4.5 for Zn²⁺/Cu²⁺ and 35 for Zn²⁺/Fe³ system. The electrodialysis enhanced with complexation appeared to be a viable method for selective removal of zinc from waste electroplating baths and similar industrial effluents.