Optimal conditions for recovering boron from seawater using boron selective resins

Abstract

We determined the optimal conditions for efficient recovery of boron from seawater using boron selective resins (BSRs). A commercialized BSR named CRB05 was adopted and prepared in two particle sizes: A fine-particulate BSR (effective particle size of 105 μm) and a coarse-particulate BSR (effective particle size of 445 μm). The performance of the two BSRs was compared in terms of boron adsorption, boron desorption, and BSR regeneration and reusability. During boron adsorption, for fine BSR, optimal reaction time, stirring speed and the amount of BSR needed for the adsorption of boron were 30 min, 150 rpm and 1 g-BSR/L respectively, whereas for coarse BSR, values of the above parameters were 300 min, 150 rpm and 3 g-BSR/L. It indicates that the fine BSR can adsorb boron about threetimes more than the coarse BSR. It also shows that the reaction rate of the fine BSR is almost ten-times higher than that of the coarse BSR. During the boron desorption, no significant difference was found between the efficiencies exhibited by the fine and the coarse BSRs. The best desorption performance can be attained with 11.9 mL/mg-B of 0.05 M H₂SO₄ and 15.9mL/mg-B of 0.25M HCl, regardless of the particle size of the BSR. Finally, the boron adsorption efficiency can be maintained at a stable level even after reusing the BSRs over ten times. The present study shows a possibility to recover boron with better efficiency from seawater in short time using the fine BSR, rather than the coarse BSR.