铁改性滑石对水中砷的吸附性能  

Adsorption performance of Fe^(3+)-modified talc for arsenic in water

作　　者：查玉娥[1] 于建[1] 卞战强[1] 郑和辉[1] 田向红[1] 张娟[1] 

机构地区：[1]中国疾病预防控制中心农村改水技术指导中心,北京102200

出　　处：《环境与健康杂志》2016年第1期69-72,共4页Journal of Environment and Health

基　　金：卫生部卫生行业科研专项(201302004)

摘　　要：目的用过渡金属盐对滑石进行改性,选取吸附水中砷效果最好的改性滑石并研究其吸附的适宜条件及吸附机制。方法通过研究不同过渡金属盐(Fe Cl3、Fe SO4、Ni SO4、Zn SO4和Cu SO4)改性滑石、加铁量(0.01~0.3 mol/L)、改性滑石投加量(1~20 g/L)、p H值(2~10)、温度(15~65℃)、水中砷的初始浓度(0.1~20 mg/L)、吸附时间(1~360 min),探讨改性滑石对砷的吸附效果影响,采用Langmuir、Freundlich等温线方程及Lagrange准一级动力学方程、准二级动力学方程、粒内扩散方程对实验数据进行了拟合。结果 Fe Cl3对滑石吸附砷的能力提高最大,用1 g铁改性滑石,砷的初始浓度为1 mg/L,在室温下,p H 7时,吸附率可达99.74%。铁改性滑石对砷的吸附符合Langmuir和Freundlich方程,属单分子层吸附且吸附容易发生,最大吸附量为qm=0.672 1 mg/g;铁改性滑石对砷的吸附动力学符合准二级动力学方程,以化学吸附为主,有多个控速步骤。结论铁改性滑石对水中砷有良好的吸附性且吸附速率较快。Objective To chose the highest adsorption performance of transition metal salts-modified talc for arsenic from aqueous solution and investigate the optimum adsorption conditions and adsorption mechanism. Methods Arsenic adsorption performance of the modified talc were investigated under different conditions,such as different transition metal salts（Fe Cl3,Fe SO4,Ni SO4,Zn SO4 and Cu SO4）-modified talc,Fe3＋concentration（0.01-0.3 mol/L）,modified talc dosage（1-20 g/L）,p H（2-10）,temperature（15-65 ℃）,initial arsenic concentration（0.1-20 mg/L） and reaction time（1-360 min）. Langmuir,Freundlich isotherm equation and Lagrange pseudo-first order kinetics equation,pseudo-second-order kinetics equation and intra-particle diffusion equation were applied to simulate the experimental parameters. Results Talc with modified Fe Cl3 displayed the highest adsorption capacity. Under the condition of arsenic original concentration of 1 mg/L,room temperature,p H 7,the adsorption rate was 99.74%. The adsorption isotherms were in accord with the Langmuir and Freundlich models,though the former was better,which was a single molecular layer adsorption and easy to occur. The maximum adsorption capacity was0.672 1 mg/g. The adsorption performance of Fe Cl3 modified talc for arsenic conformed to pseudo-second-order kinetics equation. Conclusion Talc modified with Fe3＋shows higher adsorption capacity and adsorption rate in removing arsenic from water.

关 键 词：改性滑石 砷 水 吸附 

分 类 号：R123.6[医药卫生—环境卫生学]