Characteristics of iron (hydr)oxides and Cr(VI) retention mechanisms in soils from tropical and subtropical areas of China

Wentao Wang; Liu Yang; Dong Gao; Minghao Yu; Shuqi Jiang; Jiangshan Li; Jing Zhang; Xionghan Feng; Wenfeng Tan; Fan Liu; Ming Yin; Hui Yin

doi:10.1016/j.jhazmat.2023.133107

Characteristics of iron (hydr)oxides and Cr(VI) retention mechanisms in soils from tropical and subtropical areas of China

J Hazard Mater. 2024 Mar 5:465:133107. doi: 10.1016/j.jhazmat.2023.133107. Epub 2023 Nov 29.

Authors

Wentao Wang¹, Liu Yang², Dong Gao², Minghao Yu², Shuqi Jiang³, Jiangshan Li⁴, Jing Zhang⁵, Xionghan Feng¹, Wenfeng Tan¹, Fan Liu¹, Ming Yin⁶, Hui Yin⁷

Affiliations

¹ Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; State Environmental Protection Key Laboratory of Soil Health and Green Remediation, Ministry of Ecology and Environment, Wuhan 430070, China.
² Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
³ Faculty of Resources and Environmental Science, Hubei University, Wuhan 430070, China.
⁴ State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China.
⁵ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, China.
⁶ Shiyan Ecological Environment Monitoring Center of Hubei Provincial Department of Ecology and Environment, Shiyan 442000, China. Electronic address: 1354274541@qq.com.
⁷ Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; State Environmental Protection Key Laboratory of Soil Health and Green Remediation, Ministry of Ecology and Environment, Wuhan 430070, China. Electronic address: yinhui666@mail.hzau.edu.cn.

PMID: 38043424
DOI: 10.1016/j.jhazmat.2023.133107

Abstract

Though both iron (hydr)oxides and soil organic matter (SOM) significantly influence heavy metal behaviors in soils, studies on the characteristics of natural minerals and the synergic effects of the two on Cr(VI) transformation are limited. This study investigated Cr(VI) retention mechanisms in four soils from tropical and subtropical regions of China based on a comprehensive characterization of Fe (hydr)oxides. These soils exhibited varying quantities of hematite, ferrihydrite and goethite, with distinct Al substitution levels and varied exposed crystallographic facets. Adsorption experiments revealed a positive correlation between Fe (hydr)oxide content and Cr(VI) fixation amount on colloid, which was influenced by the mineral types, Al substitution levels and facet exposures. Further, Cr(VI) was sequestered on soil by adsorption and reduction. In soils enriched with crystalline Fe (hydr)oxides, Cr(VI) reduction was primarily governed by SOM, while in soils enriched with poorly crystalline Fe (hydr)oxides, mineral-associated Fe(II) also contributed to Cr(VI) reduction. Aging experiments demonstrated that SOM and mineral-associated Fe(II) expedited Cr (VI) passivation and diminished the Cr leaching. These results improve our understanding of natural Fe (hydr)oxide structures and their impact on Cr(VI) behavior in soils, and shed light on complex soil-contaminant interactions and remediation of Cr(VI) polluted soils.

Keywords: Chromium(VI) adsorption; Iron (hydr)oxides; Microstructure; Reduction; Soil.