改性凹凸棒石对汞吸附及土壤汞钝化性能影响  

Effect of modified attapulgite on mercury adsorption and passivation in soil

作　　者：王鹏亮 刘双 张钰 钟顺清[1] WANG Pengliang;LIU Shuang;ZHANG Yu;ZHONG Shunqing(College of Geography and Tourism,Hengyang Normal University,Hengyang 421002,China)

机构地区：[1]衡阳师范学院地理与旅游学院,衡阳421002

出　　处：《环境保护科学》2025年第1期96-106,共11页Environmental Protection Science

基　　金：国家自然科学基金项目(42077297)。

摘　　要：为探索改性凹凸棒石对水体和土壤中Hg2+的去除性能,采用经提纯和酸化的凹凸棒石负载硫酸亚铁及负载硫化钠等不同改性方法制备改性凹凸棒石,通过吸附解吸试验和土壤钝化试验,研究不同改性凹凸棒石及其添加量、吸附时间、pH等对水体和土壤中Hg钝化的影响。结果表明:与凹凸棒石原矿相比,经不同方法改性凹凸棒石对于水体中的Hg2+去除效果比较好。其中经提纯凹凸棒石负载硫化亚铁(ATPF)、负载硫化钠(ATPN)与经硫酸酸化凹凸棒石负载硫化亚铁(SATP)、经盐酸酸化凹凸棒石负载硫酸亚铁(CATP)对汞的吸附率分别为98.83%、94.32%、92.61%和91.23%。改性凹凸棒石吸附过程更符合准二级动力学模型和Freundlich模型,是一个物理-化学复合的不均匀多层吸附过程,受表面扩散和颗粒内扩散控制。ATPF和ATPN解吸率较低,解吸率分别为2.29%和6.23%,具有较好的稳定性。添加ATPF和ATPN能显著提高土壤静态吸附性能,使土壤中汞向残渣态转化来降低土壤汞的生物有效性。负载硫化亚铁和硫化钠能提高凹凸棒石对水体和土壤中汞的吸附和钝化能力,是一种具有潜力的钝化吸附材料。To explore the removal performance of modified attapulgite on Hg2+in water and soil,modified attapulgite was prepared by different modification methods such as purified and acidified attapulgite loaded with ferrous sulfate and sodium sulfide.Through adsorption and desorption test and soil passivation test,the effects of different modified attapulgite and its addition amount,adsorption time and pH on Hg passivation in water and soil were studied.The results showed that,compared with the original ore of attapulgite,the modified attapulgite had better removal effect on Hg2+in water.The adsorption rates of mercury on purified attapulgite loaded with ferrous sulfide(ATPF),sodium sulfide(ATPN),sulfated attapulgite loaded with ferrous sulfide(SATP)and hydrochloric acid acidified attapulgite loaded with ferrous sulfate(CATP)were 98.83%,94.32%,92.61%and 91.23%,respectively.The adsorption process of modified attapulgite was more consistent with the quasi-second-order kinetic model and Freundlich model.It was a physico-chemical complex and heterogeneous multilayer adsorption process,which was controlled by surface diffusion and intra-particle diffusion.The desorption rates of ATPF and ATPN were 2.29%and 6.23%respectively,which showed good stability.The addition of ATPF and ATPN could significantly improve the static adsorption performance of soil,and reduce the bioavailability of soil mercury by transforming soil mercury into residual state.Loading ferrous sulfide and sodium sulfide could improve the adsorption and passivation ability of attapulgite to mercury in water and soil,which was a potential passivation adsorption material.

关 键 词：改性凹凸棒石 汞形态 吸附 负载 钝化 

分 类 号：X505[环境科学与工程—环境工程]