碱激发粉煤灰对Cs^+的吸附行为  

Adsorption Behavior of Alkali Activated Fly Ash to Cesium Ions

作　　者：罗洁[1] 张海军[2] 刘璟[1] 杨剑[3] 黄胜[1] 邓仕明[1] 

机构地区：[1]西南科技大学环境与资源学院,四川绵阳621010 [2]西南科技大学理学院,四川绵阳621010 [3]西南科技大学应用技术学院,四川绵阳621010

出　　处：《化工环保》2015年第2期192-198,共7页Environmental Protection of Chemical Industry

基　　金：西南科技大学博士科研基金项目(11zx7112)

摘　　要：将粉煤灰进行碱激发改性,运用XRD和SEM技术对碱激发粉煤灰进行了表征,通过静态平衡吸附实验研究了碱激发粉煤灰对Cs+的吸附动力学和热力学特性,并对吸附前后的碱激发粉煤灰进行了FTIR分析。表征结果显示,碱激发处理后,粉煤灰的晶相发生了改变,且粉煤灰表面密实的硬壳层被破坏。实验结果表明:在初始Cs+质量浓度为200 mg/L、吸附温度为25℃、溶液pH为10、碱激发粉煤灰投加量为12.0 g/L的条件下,碱激发粉煤灰对Cs+的平衡吸附率可达80%以上,其吸附能力比碱激发前提高了3倍以上;吸附过程可用准二阶动力学方程来描述,并较好地符合Langmuir等温吸附模型;碱激发粉煤灰对Cs+的吸附是吸热过程,且能自发进行;该过程以物理吸附为主,并伴随化学吸附。The fl y ash was modifi ed by alkali activation and characterized by XRD and SEM. The adsorption kinetics and thermodynamics characteristics of Cs＋ on alkali activated fly ash were investigated through an experiment of static equilibrium adsorption,and the alkali activated fl y ash before and after adsorption was analysed by FTIR. The characterization results show that the crystal phase of the alkali activated fl y ash is changed,and the hard shell layer on the surface of fl y ash is destroyed after alkali activation. The experimental results show that：Under the conditions of initial Cs＋ mass concentration 200 mg/L,adsorption temperature 25 ℃,solution pH 10 and alkali activated fl y ash dosage is 12.0 g/L,the equilibrium adsorption ratio of Cs＋ on the alkali activated fl y ash can reach above 80%,which is more than 3 times higher than that on the fl y ash before alkali activation;The adsorption is coincident with quasi-second order kinetics equation and fi ts Langmuir isothermal adsorption model well;The adsorption of Cs＋ on alkali activated fl y ash is a spontaneous endothermic process,and the main adsorption behavior is physical adsorption accompanied with chemical adsorption.

关 键 词：粉煤灰 碱激发 物理吸附 铯离子 放射性废水 

分 类 号：X703[环境科学与工程—环境工程]