초록 |
Powdered activated carbon (PAC) modified by cationic surfactant has high adsorption capacities to anionic contaminants. It is used to remove arsenate (H2AsO4-), chromate (CrO42-)and ferricyanide(Fe(CN)63-) in this study. Adsorption capacity of virgin activated carbon is less than 0.03 mmol of anionic pollutant per 1 g of PAC. However, adsorption capacity of PAC increases by modifying the virgin PAC with cationic surfactant. Adsorbed mass of H2AsO4-, CrO42-and Fe(CN)63-on modified PAC are enhanced as 0.1, 0.25, 0.13 mmol/g, respectively. Adsorbed mass of CrO42-is nearly twice higher than those of H2AsO4-and Fe(CN)63-. Adsorption capacity of modified PAC to H2AsO4- and Fe(CN)63- are similar. However, in multi-contaminants system, Adsorption capacities of three anionic contaminants are different. Because of valence effect, trivalent ferricyanide shows the highest adsorption affinity to modified PAC. Therefore adsorption of Fe(CN)63- increases with equilibrium concentration. Whereas adsorbed CrO42-and H2AsO4-are detached to aqueous phase. |