Intensification of demineralization process and decrease in scaling by application of pulsed electric field with short pulse/pause conditions

Abstract

Pulsed electric field (PEF) can affect positively the membrane scaling mitigation and the intensification of electrodialytic (ED) process. Recent studies considered the use of PEF with relatively long pulse/pause conditions (5–40s). The present work was focused on the application of specific PEF conditions with short pulse/pause duration as a following perspective step in improving demineralization. Therefore, in this study six conditions were tested (1s/0.33s, 1s/1s, 2s/0.5s, 2s/0.67s, 3s/0.33s, 3s/1s) in order to investigate the influence of short PEF lapses and to find the optimum among all PEF conditions. Results indicate that PEF conditions of 2s/0.5s and 2s/0.67s allowed the highest demineralization rates. A decrease of scaling on the cation-exchange membrane surface in comparison with previous data was observed in all PEF conditions. In addition, absence of scaling on the anion-exchange membrane was observed for the first time in such extreme conditions of demineralization and solution composition. These results highlighted the successful use of short pulse/pause lapses during electrodialysis.