焙烧温度对铁覆膜砂IOCS吸附Cr(VI)的影响

The effect of coating temperature on the adsorption of chromate (VI) onto iron-oxide-coated sand

采用序批试验研究了焙烧温度对铁覆膜砂(Iron Oxide Coated Sand,IOCS)吸附6价铬Cr(VI)的吸附平衡和吸附速率的影响.结果表明,铬在IOCS上的吸附平衡符合Langmuir吸附模型.低温制备IOCS具有较高吸附容量且对pH不敏感.110℃制备IOCS在pH7的最大吸附容量(0.181mg·g-1)远高于660℃制备IOCS(0.023mg·g-1).吸附过程符合准二级动力学模型.吸附速率随焙烧温度提高而下降.

The impact of coating temperature on the adsorption equilibrium and adsorption rate of Cr （VI） onto iron-oxide coated sand （IOCS） was investigated by batch tests. It was found that the Langmuir adsorption isotherm properly described the adsorption equilibrium of the Cr（VI） by IOCS. IOCS synthesized at lower coming temperatures had a higher adsorption capacity and the adsorption equilibrium was less sensitive to pH. Maximum adsorption of Cr （VI） at pH 7 for IOCS synthesized at 110℃ was found to be much higher （0. 181 mg·g ^-1 ） than that （0.023 mg·g ^-1 ） for IOCS synthesized at 660℃. The adsorption kinetics fit a pseudo-second-order rate model well. The adsorption rate decreased with increased coating temperature.