Effect of some parameters on the performance of eletrodialysis using new type of PVDF–SiO2 ion-exchange membranes with single salt solution Original Research Article

The effect of operating condition on the performance of new type of PVDF–SiO2 organic–inorganic ion-exchange membranes used in electrodialysis process was investigated with single salt solution in comparison to PVDF membranes. The experimental results indicated that better transport properties of PVDF–SiO2 membranes may be responsible for the limited current density (LCD) of the membranes higher than that of PVDF membranes. The LCD values of PVDF–SiO2 and PVDF membranes at NaCl solution of 5000 mg/L were 1.43 mA/cm2 and 1.13 mA/cm2, respectively. In addition, desalination ratio increased with increasing current density and feed flow rate. It was also found that at the optimum operating condition, the removal ratios of Na+, Ca2+, Cl− and SO42− by electrodialysis employing PVDF–SiO2 membranes were 97.7%, 93.5%, 96.5% and 88.5%, respectively, and the removal ratios of the ions in the presence of PVDF membranes were 91.4%, 88.4%, 92.5% and 85.7%, respectively. It can be concluded that these PVDF–SiO2 organic–inorganic ion-exchange membranes with better membrane properties can be used in electrodialysis process.