典型吸附材料对含Cs废水的吸附效能对比研究

Adsorption of cesium-containing wastewater by typical materials

选取活性炭、高岭土、蒙脱土、膨润土、沸石和凹凸棒土6种典型吸附材料,通过静态批实验,探索吸附过程关键影响要素(吸附时间、初始质量浓度、溶液pH和温度)对吸附过程的影响,并结合吸附动力学模型和吸附等温线,实现6种吸附材料对含铯(Cs)废水的吸附效能对比研究.结果表明:在相同的吸附时间内,6种吸附材料对Cs的吸附效能由高到低排序为沸石、凹凸棒土、膨润土、蒙脱土、活性炭、高岭土;沸石对Cs的吸附率几乎不受初始质量浓度和温度的影响,其余材料适合在偏碱性环境中、30℃条件下去除Cs;活性炭、高岭土、蒙脱土和凹凸棒土均适合在低初始质量浓度下去除Cs;6种吸附材料对Cs的吸附过程均非单一吸附机制,而是多种吸附机制共同作用的结果.6种典型吸附材料中,沸石、凹凸棒土与膨润土对含Cs放射性废水的处理具有明显效果,特别是沸石,吸附性能好且适应性广泛,在放射性废水的处置中具有一定应用价值.

Effect of exposure time,initial concentration,pH and temperature on adsorption of wastewatercontained cesium(Cs)by activated carbon,kaolin,montmorillonite,bentonite,zeolite and attapulgite was investigated.Kinetics and isotherms revealed that for a set adsorption time,adsorption efficiency was zeolite,attapulgite,bentonite,montmorillonite,activated carbon,kaolin.Zeolite adsorption of Cs was almost independent of initial concentration or temperature.Cs removal by other materials all improved at alkaline pH at 30℃.Attapulgite,montmorillonite,activated carbon,and kaolin could be used for Cs removal at low initial concentrations.Cs adsorption by these six types of materials was the result of combined adsorption.Out of the six adsorption materials,zeolite,attapulgite,and bentonite showed clear removal and could be used for practical applications for the disposal of radioactive Cs in wastewater,with zeolite being the best for such purpose.