Remediation of arsenic contaminated soil by sulfidated zero-valent iron  

作　　者：Junlian Qiao Yang Liu Hongyi Yang Xiaohong Guan Yuankui Sun 

机构地区：[1]State Key Laboratory of Pollution Control and Resources Reuse,College of Environmental Science and Engineering,Tongji University,Shanghai,200092,China [2]Shanghai Institute of Pollution Control and Ecological Security,Shanghai,200092,China

出　　处：《Frontiers of Environmental Science & Engineering》2021年第5期85-95,共11页环境科学与工程前沿（英文）

基　　金：the National Key Research and Development Program of China(No.2019YFC1805202);the National Natural Science Foundation of China(Nos.21876129 and 51608431).

摘　　要：In this study,the influences of sulfidation on zero-valent iron(ZVI)performance toward As(Ⅴ)immobilization in soil were systemically investigated.It was found that,compared to unamended ZVI,sulfidated ZVI(S-ZVI)is more favorable to immobilize As(Ⅴ)in soil and promote the conversion of water soluble As to less mobile Fe-Mn bound As.Specifically,under the optimal S/Fe molar ratio of 0.05,almost all of the leached As could be sequestrated by>0.5 wt.%S-ZVI within 3 h.Although the presence of HA could decrease the desorption of As from soil,HA inhibited the reactivity of S-ZVI to a greater extent.Column experiments further proved the feasibility of applying S-ZVI on soil As(Ⅴ)immobilization.More importantly,to achieve a good As retention performance,S-ZVI should be fully mixed with soil or located on the downstream side of As migration.The test simulating the flooding conditions in rice culture revealed there was also a good long-term stability of soil As(Ⅴ)after S-ZVI remediation,where only 0.7%of As was desorbed after 30 days of incubation.Magnetic separation was employed to separate the immobilized As(Ⅴ)from soil after S-ZVI amendment,where the separation efficiency was found to be dependent of the iron dosage,liquid to soil ratio,and reaction time.Toxicity characteristic leaching procedure(TCLP)tests revealed that the leachability of As from soil was significantly reduced after the S-ZVI amendment and magnetic separation treatment.All these findings provided some insights into the remediation of As(Ⅴ)-polluted soil by ZVI.

关 键 词：SOIL As(Ⅴ) SULFIDATION Zero-valent iron Magnetic separation 

分 类 号：X53[环境科学与工程—环境工程]