阴离子黏土吸附砷酸根离子热力学研究  

Thermodynamic Study on the Anionic Clay Adsorbed As(Ⅴ)

作　　者：姚尚和[1] 孙世群[1] 彭书传[1] 周晓铁[2] 杨远登 

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥230009 [2]安徽省环境科学研究院,安徽合肥230061

出　　处：《安徽农业科学》2010年第5期2500-2502,共3页Journal of Anhui Agricultural Sciences

基　　金：国家自然科学基金(40472026;40672027)

摘　　要：利用共沉淀水热法制备镁铝阴离子黏土材料,研究了其水溶液对砷酸根[As(V)]离子的吸附热力学及其机理。结果表明:在303～333 K和试验浓度范围内,阴离子黏土对水中As(V)的吸附平衡数据符合Langmuir和Freundlich吸附等温方程。阴离子黏土对水中As(V)的吸附是吸热过程;根据热力学函数关系计算出As(V)在阴离子黏土上的吸附焓为2.85 kJ/mol,吉布斯吸附自由能改变量为-6.64～-5.90 kJ/mol,吸附自由能的变小是As(V)在阴离子黏土上吸附的推动力,吸附熵变为29.38 J/(mol.K)。Mg-Al anionic clay materials were prepared by co-precipitation hydrothermal method and the adsorption thermodynamic and mechanism of arsenate anion from its aqueous solutions were investigated.Equilibrium data for the adsorption of arsenate anion from aqueous solutions within the temperature rang of 303-333 K and investigative concentration rang was obtained and correlated with a Langmuir-type and Freundlich-type isotherm equations.The results showed that the process of sorption of arsenate anion from aqueous solutions by Mg-Al anionic clay was an endothermic process.The adsorption parameters of thermodynamic were calculated according to the relationship of thermodynamic function,enthalpy was 2.85 KJ/mol,adsorption free energy was in the range of-6.64——5.90 kJ/mol,the adsorption happened because of the decrease of Gibbs free energy and adsorption entropy was 29.38 J/（mol ·K）.

关 键 词：阴离子黏土 砷酸根 吸附作用 热力学 

分 类 号：X703[环境科学与工程—环境工程]