Removal of boron from water by electrodialysis: effect of feed characteristics and interfering ions

Boron removal from aqueous solution by electrodialysis was studied as a function of solution pH, applied voltage, flow rate and initial boron concentration. TS-l-l0 electrodialysis equipment (Tokuyama) modified with rotameters was employed for experimental studies. It was obtained that the highest boron transport was achieved at pH 10.5 due to the increase in dissociation of boric acid in the solution. When initial boron concentration in the solution is high, percent removal of boron increased. The existence of chloride affected the efficiency of boron removal. The effect of sulphate ions was not so apparent for boron removal although the process time for boron separation became longer in the presence of sulphate ions. It was obtained that the specific power consumption increased when the boron concentration in the solution and pH of solution was increased. SPC values increased as the number of ionic species in the solution increased.