The efficiency and performance of electrodialysis process can be affected by the limiting current density (LCD). LCD is a critical parameter that should be determined based on operation condition of electrodialysis. In this study, the effect of concentration on LCD was investigated. LCD was determined using different methods, i.e., V/I, R/I and ????/I curves. The multi-salt solution of Na2SO4, Na2C2O4, and NaCH3COO were used with three concentrations of 1000, 700 and 300 ppm. The results showed that LCD value increased with increasing feed concentration, and increasing the current intensity more than the limiting current value does not have much effect on the removal of the ions and only water molecules are degraded.
