关键词: 电渗析, 脱盐, 浓缩, 多级逆流, 浓差扩散, 水渗漏, 膜通量

Abstract: Single-stage electrodialysis and multi-stage counter-current electrodialysis were used, respectively, to desalinate ammonium sulfate solution at the concentration of 0.52 mol/L under current-constant condition. The results showed that the phenomena of concentration diffusion and water leakage were obviously alleviated by using a multi-stage counter-current electrodialysis, while they were severe in the end period by using single-stage electrodialysis. Comparing two-stage electrodialysis and three-stage electrodialysis with single-stage one, the removal amount of salt in dilute cell was increased by 7.9% and 22.5%, the concentration of salt in concentrated cell increased by 1.6% and 6.5%, the flux increased by 7.0% and 18.5%, and the energy consumption reduced by 12.0% and 32.0%, respectively.

Key words: electrodialysis, desalination, concentration, multi-stage counter-current, concentration diffusion, water leakage, flux