Improved performance and applicability of copper-iron bimetal by sulfidation for Cr(VI) removal

Min Qu; Huixia Chen; Yuan Wang; Xingrun Wang; Xuejiao Tong; Shupeng Li; Hongbin Xu

doi:10.1016/j.chemosphere.2021.130820

Improved performance and applicability of copper-iron bimetal by sulfidation for Cr(VI) removal

Chemosphere. 2021 Oct:281:130820. doi: 10.1016/j.chemosphere.2021.130820. Epub 2021 May 11.

Authors

Min Qu¹, Huixia Chen², Yuan Wang³, Xingrun Wang⁴, Xuejiao Tong⁵, Shupeng Li⁶, Hongbin Xu¹

Affiliations

¹ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China.
² CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China. Electronic address: hxchen@ipe.ac.cn.
³ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China; Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China.
⁴ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
⁵ Yuhuan Environmental Technology Co. LTD., Shijiazhuang, 050091, Hebei Province, China.
⁶ Beijing Construction Engineering Group Environmental Remediation Co. Ltd., Beijing, 100015, China.

PMID: 34015648
DOI: 10.1016/j.chemosphere.2021.130820

Abstract

The reactivity of zero-valent iron (ZVI) for the Cr(VI) removal in groundwater is mainly limited by the formation of a passivation layer during its application in permeable reactive barrier (PRB). A kind of sulfidated copper-iron bimetal (S-ZVICu) with high reactivity for Cr(VI) removal was prepared by depositing FeS_x onto copper modified ZVI via a one-pot method. The surface characteristic, reactivity and Cr(VI) removal performance of S-ZVICu were investigated. It was found that S-ZVICu had a Cr(VI) removal capacity as high as 67.5 mg/g and little risk of secondary contaminant of Cu(II). The optimal Cu/Fe mass ratio and S/Fe molar ratio were 0.0125 and 0.084, respectively. The S-ZVICu exhibited great superiority of Cr(VI) removal compared with ZVI, sulfidated ZVI (SZVI) and coper-iron bimetal (ZVICu). Mineralogy and morphology analysis showed that S-ZVICu had a hierarchical structure of Fe⁰/Cu⁰/FeS_x, which could effectively reduce the risk of secondary contaminant of copper ions. The mechanism analysis suggested that the copper and FeS_x successively plated on the surface of ZVI played a dual role in promoting the corrosion of zero-valent iron, and was facilitated to electron transfer between Fe⁰, Cu⁰, FeS_x and Cr(VI). In addition, the loose FeS_x layer had a positive effect on alleviating the oxidation of ZVI in air, which was helpful in maintaining the reactivity of S-ZVICu in the air. S-ZVICu is an environmentally friendly material for sustainable and effective removal of Cr(VI) in groundwater.

Keywords: Chemical modification; Cr(VI) removal; Groundwater; Sulfidation; Zero-valent iron.

MeSH terms

Chromium / analysis
Copper
Corrosion
Iron*
Water Pollutants, Chemical* / analysis

Substances

Water Pollutants, Chemical
Chromium
chromium hexavalent ion
Copper
Iron