天然磁黄铁矿吸附水中As(Ⅲ)的性能及机理  

ADSORPTION PERFORMANCE AND MECHANISM OF NATURAL PYRRHOTITE FOR As(Ⅲ)IN WATER

作　　者：关梦莎 罗黎煜 沈思文 周立松 邱江坤 李睿华[1] GUAN Meng-sha;LUO Li-yu;SHEN Si-wen;ZHOU Li-song;QIU Jiang-kun;LI Rui-hua(School of the Environment,Nanjing University,Nanjing 210046,China)

机构地区：[1]南京大学环境学院,南京210046

出　　处：《环境工程》2021年第2期33-40,共8页Environmental Engineering

基　　金：国家自然科学基金重大项目(0211-136040)。

摘　　要：砷是地下水中最常见的污染物之一,过量摄入会严重危害人体健康。含铁矿物可以高效去除水中的As。以天然磁黄铁矿为As(Ⅲ)吸附剂,研究了吸附过程中的动力学、等温线和热力学,以及p H、无机阴离子对As(Ⅲ)吸附去除的影响。结果表明:磁黄铁矿对As(Ⅲ)的吸附在48 h可达到平衡;吸附过程符合Langmuir等温模型,在As(Ⅲ)初始浓度为1~200 mg/L,23~33℃下,天然磁黄铁矿对As(Ⅲ)的饱和吸附量(以As计)为3.5~4.5 mg/g;吸附量随着温度升高而增大,吸附过程表现为自发吸热熵增反应;在p H为7时,吸附效果达到最佳去除率(95.51±0.30)%;PO34-对吸附有明显的抑制作用。X射线电子能谱分析表明,吸附过程包括物理吸附和化学吸附,即包括矿物自身缺陷结构导致的位点吸引、As和S配位离子交换及氧化还原产物羟基氧化铁的配位沉淀。表明利用磁黄铁矿吸附As(Ⅲ),简化了传统材料和方法上将As(Ⅲ)氧化为As(Ⅴ)的烦琐步骤,有较好应用前景。As one of the most common pollutants in groundwater,excessive arsenic intake will seriously threaten human health.The kinetics,isotherm and thermodynamics in the adsorption process were analyzed,and the effects of p H and inorganic anions on the adsorption of As(Ⅲ)in water by natural pyrrhotite were studied.It was found that adsorption of As(Ⅲ)by pyrrhotite reached equilibrium in 48 h.Adsorption processes followed the Langmuir isothermal model,in the range of 1~200 mg/L for initial concentration,and the saturated adsorption capacity of As(Ⅲ)on natural pyrrhotite from 23℃to33℃was 3.5~4.5 mg/g(by As element).The adsorption capacity increased with the increase of temperature,and the adsorption process was a spontaneous endothermic reaction.And the best effect occurred when p H was 7,where the removal rate of As(Ⅲ)was(95.51±0.30)%.PO34-had obvious inhibition on the adsorption.X-ray photoelectron spectroscopy analysis showed that the adsorption involved physical adsorption and chemical adsorption,including site attraction caused by the defect structure of minerals,As and S coordination ion exchange,and the coordination precipitation of iron hydroxide oxide.The results showed that the adsorption of As(Ⅲ)by pyrrhotite simplified the tedious steps of the oxidation of As(Ⅲ)to As(Ⅴ)by materials and methods,and had good prospect of utilization.

关 键 词：吸附 磁黄铁矿 亚砷酸盐As(Ⅲ) X射线电子能谱分析 

分 类 号：X523[环境科学与工程—环境工程]