纳米二氧化锰对水中Cu^(2+)和Cd^(2+)的吸附特性  

Adsorption Properties of Nano MnO_2 for Cu^(2+)and Cd^(2+) in Water

作　　者：黄一帆[1] 于志红[1] 廉菲[1] 沈跃[1] 宋正国[1] 

机构地区：[1]农业部环境保护科研监测所,天津300191

出　　处：《环境工程技术学报》2016年第4期350-356,共7页Journal of Environmental Engineering Technology

基　　金：国家自然科学基金项目(41273136);国家高技术研究发展计划(863计划)项目(2012AA101404-5)

摘　　要：采用水相-有机相两相法合成了纳米二氧化锰(nMnO2),观测了其对水中Cu^(2+)和Cd^(2+)的吸附性能,并应用Langmuir、Freundlich、准一级动力学、准二级动力学和Elovich等方程分析了 nMnO2对Cu^(2+)和Cd^(2+)的吸附特征。结果表明: nMnO2比表面积为141.66 m2/g; nMnO2对Cu^(2+)和Cd^(2+)的吸附分别在750和300 min达到平衡,吸附过程符合准二级动力学模型与Elovich模型, nMnO2对Cd^(2+)的吸附速率要高于Cu^(2+); nMnO2对Cu^(2+)和Cd^(2+)的吸附特征符合Langmuir方程,其对Cu^(2+)和Cd^(2+)的最大吸附量分别为104.5和89.1 mg/g; nMnO2对Cu^(2+)和Cd^(2+)的吸附过程中,ΔG<0,ΔH<0,而ΔS>0,温度升高有利于吸附反应的进行,提高温度会提高 nMnO2对重金属离子的吸附性能; nMnO2对Cu^(2+)和Cd^(2+)的吸附能力受pH(3~6)影响较大,提高体系的pH,会明显增加 nMnO2对Cu^(2+)和Cd^(2+)的吸附量。该 nMnO2合成工艺简单,对重金属Cu^(2+)和Cd^(2+)具有较好的吸附性能,是较好的吸附材料。Nano manganese dioxide（ nMnO2） was synthesized by the two-phase method of aqueous phase and organic phase,its adsorption property of Cu^（2＋）and Cd^（2＋）in water observed,and the Cu^（2＋）and Cd^（2＋）adsorption characteristics analyzed by Langmuir,Freundlich,Pseudo-first-order kinects,Pseudo-sceond-order kinects and Elovich model. The results showed that the nMnO2 specific surface area is 141. 66 m2/g. The adsorption of Cu^（2＋）and Cd^（2＋）reached equilibrium in 750 min and 300 min,respectively,the adsorption process followed pseudosecond-order kinetics model and Elovich model,and the adsorption rate of Cd^（2＋）was higher than that of Cu^（2＋）. The adsorption characteristics of nMnO2 on Cu^（2＋）and Cd^（2＋）fit the Langmuir equation,and the maximum adsorption amount of Cu^（2＋）and Cd^（2＋）was 104. 5 mg/g and 89. 1 mg/g respectively. In the adsorption process of Cu^（2＋）and Cd^（2＋）,ΔG 0,ΔH 0 and ΔS 0,temperature increase favored the adsorption reaction,so the temperature improving would increase the adsorption of nMnO2 on heavy metal ions. The adsorption ability of nMnO2 on Cu^（2＋）and Cd^（2＋）was greatly influenced by pH in the range of 3-6. The improvement of the system pH would increase the adsorption capacity of nMnO2 on Cu^（2＋）and Cd^（2＋）. The synthesis process of nMnO2 is simple and it has good adsorption performance on heavy metal Cu^（2＋）and Cd^（2＋）,and it can thus be used as a good adsorption material.

关 键 词：铜 镉 纳米二氧化锰(nMnO2) 吸附 

分 类 号：X52[环境科学与工程—环境工程]