Separation and Purification Technology, Vol.59, No.1, 101-107, 2008
Effect of characteristics of activated carbon on removal of bromate
This study evaluates how the characteristics of activated carbon (AC) influence the adsorption-reduction of bromate (BrO3-) by performing kinetic and isotherm tests. Experimental results reveal that both physical and chemical effects simultaneously affect the adsorption-reduction process. The wood-based carbons contained more mesopores than coconut- and coal-based carbons, resulting in the adsorption of more BrO3-. The equilibrium- and maximum-adsorption capacities were calculated as a function of the effect of mesopore volume. The carbon surface chemistry seems to be significant in the adsorption-reduction process. Activated carbons with high pH(zpc) values and many basic groups exhibit a neutral or positive charge under typical pH conditions, promoting BrO3- adsorption-reduction at the carbon surface. The kinetic data obtained from three forms of carbons have been analyzed using three kinetic models-pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Among the kinetic models studied, the intraparticle diffusion was the best applicable model to describe the adsorption of BrO3- onto AC. (C) 2007 Elsevier B.V. All rights reserved.