BORON REMOVAL FROM AQUA SOLUTION WITH A HYBRID SYSTEM (CRYSTALLIZATION-FILTRATION)

Boron ores are used in production of various boron compounds such as boric acid, borax and boron oxide. Boric acid is produced by reacting colemanite with sulphuric acid, and borax is produced by dissolving tincal in hot water. During those production processes, a large quantity of boron oxide is discharged. In this study, evaluation of wastewater of boron industry discharged directly to environment during borax and boric acid production was investigated to recover B2O3 and to reduce the toxic effect of waste. For this purpose, dimethyl sulfoxide (DMSO) was used to attract the water in the solution and to crystallize B2O3 and then B2O3 was filtered.The best result with DMSO was 290 mg L-1 effluent boron concentration for 3700 mg L-1 influent boron concentration with efficiency of 92%. After DMSO was added to the boron solution, boron begun to crystallized. For the separation of solid-liquid, cross-flow membrane filtration and vacuum filtration were used respectively, and vacuum filtration was found to be more efficient. The result of this study showed that the boron recovery efficiency was as high as 95%.