Format

Send to

Choose Destination
Chemosphere. 2016 Feb;144:1313-8. doi: 10.1016/j.chemosphere.2015.09.105. Epub 2015 Oct 23.

Remediation of arsenic contaminated soil by coupling oxalate washing with subsequent ZVI/Air treatment.

Author information

1
Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, PR China.
2
Environmental Science Research Institution, College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
3
Environmental Science Research Institution, College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: chenjing@mail.hust.edu.cn.
4
Environmental Science Research Institution, College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: hust-esri2009@hotmail.com.

Abstract

The application of a novel coupled process with oxalate washing and subsequent zero-valent iron (ZVI)/Air treatment for remediation of arsenic contaminated soil was investigated in the present study. Oxalate is biodegradable and widely present in the environment. With addition of 0.1 mol L(-1) oxalate under circumneutral condition, 83.7% and 52.6% of arsenic could be removed from a spiked kaolin and an actual contaminated soil respectively. Much more oxalate adsorption on the actual soil was attributed to the higher soil organic matter and clay content. Interestingly, oxalate retained in the washing effluent could act as an organic ligand to promote the oxidation efficiency of ZVI/Air at near neutral pH. Compared with the absence of oxalate, much more As(III) was oxidized. Arsenic was effectively adsorbed on iron (hydr)oxides as the consumption of oxalate and the increase of pH value. For the actual soil washing effluent, about 94.9% of total arsenic was removed after 120 min's treatment without pH adjustment. It has been demonstrated that As(V) was the dominant arsenic speciation adsorbed on iron (hydr)oxides. This study provides a promising alternative for remediation of arsenic contaminated soil in view of its low cost and environmental benign.

KEYWORDS:

Adsorption; Arsenic; Oxalate; Oxidation; Soil washing; Zero-valent iron

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center