Transport and fate of Cu and Cd in contaminated paddy soil under acid mine drainage

Yan Pan; Han Ye; Yang Yang; Chengfang Yang; Xiaofei Li; Tengfei Ma; Zhi Dang; Guining Lu

doi:10.1016/j.jenvman.2023.117517

Transport and fate of Cu and Cd in contaminated paddy soil under acid mine drainage

J Environ Manage. 2023 May 15:334:117517. doi: 10.1016/j.jenvman.2023.117517. Epub 2023 Feb 17.

Authors

Yan Pan¹, Han Ye², Yang Yang³, Chengfang Yang⁴, Xiaofei Li⁵, Tengfei Ma², Zhi Dang⁶, Guining Lu⁷

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; School of Environmental Engineering, Xuzhou University of Technology, Xuzhou, 221000, PR China.
² School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.
³ National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro- Environ. Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, PR China.
⁴ School of Environmental Engineering, Xuzhou University of Technology, Xuzhou, 221000, PR China.
⁵ School of Environmental and Chemical Engineering, Foshan University, Foshan, 528000, PR China.
⁶ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; The Ministry of Education Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, South China University of Technology, Guangzhou, 510006, PR China.
⁷ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China. Electronic address: lutao@scut.edu.cn.

PMID: 36801678
DOI: 10.1016/j.jenvman.2023.117517

Abstract

Long-term heavy metals accumulation caused by acid mine drainage (AMD) irrigation in paddy soils poses a severe threat to environmental health. However, the soil adsorption mechanisms under AMD flooding remain unclear. This study provides key insights into the fate of heavy metals in soil, particularly the retention and mobility mechanisms of Cu (copper) and Cd (cadmium) after AMD flooding. The migration and fate of Cu and Cd in uncontaminated paddy soils treated by AMD in Dabaoshan Mining area was investigated via column leaching experiments in the laboratory. The maximum adsorption capacities of Cu (658.04 mg kg^-1) and Cd (335.20 mg kg^-1) cations were predicted and the breakthrough curves were fitted using the Thomas and Yoon-Nelson models. Our findings demonstrated that Cd was more mobile than Cu. Furthermore, the soil had a greater adsorption capacity for Cu than Cd. Tessier's five-step extraction method was used to determine Cu and Cd fractions in leached soils at different depths and times. After AMD leaching, the relative and absolute concentrations of the easily mobile forms were all increased at different soil depths, thus increasing the potential risk to the groundwater system. Mineralogical characterization of the soil indicated that AMD flooding leads to the formation of mackinawite. This study provides insights into the distribution and transportation processes of soil Cu and Cd and their ecological effects under AMD flooding, as well as a theoretical basis for the establishment of corresponding geochemical evolution models and environmental governance in mining areas.

Keywords: Acid mine drainage; Cadmium; Copper; Paddy soil; Soil column.

MeSH terms

Cadmium
China
Conservation of Natural Resources
Environmental Policy
Metals, Heavy* / analysis
Soil
Soil Pollutants* / analysis

Substances

Cadmium
Metals, Heavy
Soil
Soil Pollutants