CONTINUOUS ELECTROPERMUTATION WITH ION-EXCHANGE TEXTILES

A continuous electropermutation process using ion-exchange textiles ha s been developed in order to eliminate cations from low concentration solutions. The applied voltage was used simultaneously as the driving force for extracting the cations and regenerating the ion-exchange tex tiles. Due to their sheet form and swelling in aqueous solutions, thes e ion-exchange materials provide a good contact with ion-exchange memb ranes. This process was tested with NaCl solutions under various exper imental conditions; then it was applied to treate a solution containin g metal ions such as Zn2+. The study carried out with a laboratory pil ot developing an active membrane area of 20 cm(2) showed that the proc ess is able to achieve high levels of removal (>95%) and to concentrat e cations in small volumes of the receiving compartment. The presence of ion-exchange textiles in the feed compartment of the ED stack allow s a lower power consumption than with conventional electrodialysis.