Removal of boron from aqueous solution by 2,3-dihydroxybenzaldehyde modified silica gel

Abstract

2,3-Dihydroxybenzaldehyde modified silica gel (SGDHB) was prepared and then used for the removal of boron. Adsorption of boron on the SGDHB was examined with respect to the equilibrium adsorption, kinetics and as a function of pH. Boron is strongly retained on the SGDHB between pH 7 and pH 9. The results indicated that the adsorption equilibrium was well described by the Langmuir equation. The SGDHB exhibited an excellent sorption capacity with 3.812 mmol B/g SGDHB under experimental conditions. The material shows reasonably rapid sorption ability, with boron in 25 mL of 0.01 M H3BO3 solution being removed almost completely within 30 min of contact time with 0.12 g of the modified silica gel. The SGDHB was demonstrated to be an efficient sorbent for the removal of boron.