| Abstract |
| In this study, adsorption characteristics of thermally treated crushed concrete granules (TTCCG) for Cr(Ⅵ) were investigated. Adsorption experiments have been conducted in batch conditions. From the experiments using TTCCG at different temperatures (100, 300, 500, 700, 900 ℃), it was found that the adsorption capacity of TTCCG increased with increasing thermal treatment temperature and TTCCG at 900 ℃(TTCCG900) was shown to be an adsorbent with highest adsorption capacity for Cr(Ⅵ). Kinetic adsorption test and model analysis showed that Cr(Ⅵ) adsorption to TTCCG900 was dependent on both intra-particle diffusion and chemisorption. Equilibrium test demonstrated that the maximum Cr(Ⅵ) adsorption capacity of TTCCG900 was 0.1785 mg/g. Additional batch experiments indicated that Cr(Ⅵ) adsorption to TTCCG900 was the highest at pH 3 and decreased with increasing pH. Also, Cr(Ⅵ) adsorption to TTCCG900 decreased in the presence of anions such as nitrate, sulphate, and phosphate. The Cr(Ⅵ) adsorption to TTCCG900 was less in seawater than in deionized water. This study demonstrated that TTCCG at high temperature could increase its adsorption capacity for Cr(Ⅵ). |
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| Key Words |
| Heavy metals, Hexavalent chrome, Crushed concrete, Adsorption, Calcination |
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