巯基棉对废水中镉的吸附

Cadmium Adsorption of Sulfhydryl Cotton in Wastewater

通过硫代乙醇酸对巯基棉进行改性后对废水中的镉离子进行了吸附研究。结果表明:50mL 25mg·L^(-1)的镉标准溶液中,在pH=7以及巯基棉用量为0.2g时能达到良好的吸附效果(吸附率超过90%)。巯基棉对镉离子的吸附可用伪二级动力学方程拟合,吸附在100min左右达到平衡。吸附等温线可用Langmuir等温式拟合,温度升高饱和吸附量减小,因此低温有利于该吸附反应的进行。

The adsorption kinetics and thermodynamics of cadmium（Ⅱ）onto the sulfhydryl cotton were investigated in this paper.The best conditions were confirmed that pH was 7and sulfhydryl cotton was 0.2g in 50 mL 25mg·L^-1 cadmium solution（adsorption rate over 90%）.The sorption kinetics process of cadmium could be well described by pseudo-second-order kinetic rate equation.The sorption equilibrium could be established within 100 min.The sorption isotherms could be well described by the Langmuir isotherm.Estimation of the thermodynamic parameters indicated that the sorption was found to be favored by a lower temperature.