Influence of water hardness on removal of copper ions by ion-exchange-assisted electrodialysis Original Research Article

The organic ion exchangers (Dowex HCR-S, Dowex 50WX-2) and inorganic ion exchangers with phosphate functional groups (zirconium phosphates ZrP-1, ZrP-2) were studied as transport media for ion-exchange-assisted electrodialysis of diluted solutions containing Cu (II) ions. The ion-exchange and electric conductive properties of ion exchangers containing Cu(II) ions were studied. The most conductive exchangers were chosen. The adsorption data showed a high selectivity of the zirconium phosphate towards copper ions in a concentration range from 0 to 0.5 mmol. Both exchangers were tested in ion-exchange-assisted electrodialysis of a 10−2 M solution, containing copper and hardness ions in a ratio of 1:9. It was found that efficiency of removal of the Cu(II) ions was better for the inorganic ion exchanger.