Boron behavior during desalination of sea and underground water by electrodialysis

The degree of boron removal and its residual content in desalinated water vs. the feed boron concentration and the total salt content of a solution by means of electrodialysis have been studied. A comparative analysis of treatment of waters containing boron by the electrodialysis using the heterogeneous [MK-40 and MA-40 (Russia)], homogeneous [MK-100 and MA-100 (Ukraine)], and IONICS [CR67-HMR and anion-204-8XZL-366 (5188C) (USA)] membranes has been made. If the feed concentration of boron in water subjected to separation is in excess of 4.5 mg/l, even optimum conditions for each membrane pair do not permit the decrease of the boron concentration below a range of 0.3 to 0.5 mg/l. Under these conditions a specific pH of a solution and an increase in the degree of desalination to 0.2 g/l are required.