不同水滑石对水体中砷(As^(5+))的吸附去除  

Adsorption and Removal of Arsenic(As^(5+))in Water by Different Hydrotalcites

作　　者：麻梦梦 周丹[1] 王起晗 黄艺[1] Ma Mengmeng;Zhou Dan;Wang Qihan;Huang Yi(School of Ecological Environment,Chengdu University of Technology,Chengdu,Sichuan 610059)

机构地区：[1]成都理工大学生态环境学院,四川成都610059

出　　处：《非金属矿》2023年第1期86-90,共5页Non-Metallic Mines

基　　金：四川省科技计划项目(2021JDTD0013,2021YFQ0066);珠峰科学研究计划(2020ZF11405)。

摘　　要：采用共沉淀法制备了镁铝水滑石(Mg-Al LDHs)、镁铁水滑石(Mg-Fe LDHs)和镁锰水滑石(Mg-Mn LDHs)3种水滑石,利用X射线衍射(XRD)仪和傅里叶红外光谱(FTIR)仪表征了3种水滑石的基本性质,通过等温吸附试验和吸附动力学试验研究了不同水滑石材料对水体中砷(As^(5+))的去除性能。结果表明,3种水滑石对水中As^(5+)的吸附过程均符合Langmuir吸附模型及准二级动力学模型,拟合结果显示,Mg-Fe LDHs对As^(5+)的吸附量最大,为202.429 mg/g;Mg-Mn LDHs对As^(5+)的吸附速率最快,为0.007150 mg/(g⋅min)。通过吸附前后FTIR表征试验,结合水滑石特殊的结构性质,推断水滑石对As^(5+)的吸附机理为砷酸根扩散至水滑石层状孔隙后,水滑石层板阳离子与砷酸根发生表面络合。In this study,three different hydrotalcites(Mg-Al LDHs,Mg-Fe LDHs and Mg-Mn LDHs)were prepared by the co-precipitation method.The basic properties of the three hydrotalcites were characterized by XRD and FTIR.The removal performance of different hydrotalcite materials for As^(5+)in water was studied by the isothermal adsorption test and adsorption kinetics test.The experimental results showed that the isothermal adsorption models of the three hydrotalcites were in line with the Langmuir adsorption model,and the adsorption kinetic model was more in line with the quasi-second-order kinetic model.The model fitting results showed that the adsorption capacity of Mg-Fe LDHs for As^(5+)was the largest,up to 202.429 mg/g.The adsorption rate of As^(5+)on Mg-Mn LDHs was the fastest,up to 0.007150 mg/(g·min).By FTIR spectrum characterization test before and after adsorption,combined with the special structural properties of hydrotalcite,it is concluded that the adsorption mechanism of hydrotalcite for As^(5+)was that after the diffusion of arsenate to the layered pores of hydrotalcite,the surface complexation of hydrotalcite lamellar cations and arsenate occurred.

关 键 词：水滑石 砷(As^(5+)) 吸附 环境水体 

分 类 号：X52[环境科学与工程—环境工程] O647.3[理学—物理化学]