有机膨润土对Cr(Ⅵ)模拟废水的吸附特性

Experimental research on the removal of Cr(Ⅵ) from wastewater using organic bentonite

采用扫描电子显微镜（SEM）、低温氮气物理吸附仪对有机膨润土的表面形貌和孔结构特性进行表征,系统考察了吸附时间、膨润土用量、p H值、温度、六价铬初始浓度对模拟废水中六价铬脱除的影响,并从有机膨润土结构、吸附机理等角度分析其对模拟废水中Cr（Ⅵ）的吸附特性。实验结果表明,该有机膨润土片层结构明显,孔隙较发达,孔径分布较宽（主要分布在3-24nm之间）,为典型的介孔材料,有利于污染物在有机膨润土内的迁移和扩散;该有机膨润土对Cr（Ⅵ）具有良好的吸附性能,在20℃、p H=6、20min条件下,2g膨润土对六价铬（50mg/L,50m L）的脱除率高达94.9%,此时吸附量为1.19mg/g.

SEM and the N2 physical adsorption analyzer were applied to characterize the porous structure and surface morphology of organic bentonite. The effects of contact time,mass of organic bentonite,pH values,removal temperature and the initial concentration of Cr（Ⅵ） on its removal were also investigated. The results suggested that organic bentonite had visible lamellar structure, pore structure and pore size （pore size distribution range 3-24nm） were well-developed,indicating that organic bentonite as a typical mesoporous material,in favor of pollutants migration and proliferation. The organic bentonite also demonstrated a high removal rate at 20℃、pH=6、20min absorption time. Under the above conditions,2g organic bentonite achieved of 94.9% removal rate of 50mg/L Cr（Ⅵ） in 50mL solution.