Antimony mobility in soil near historical waste rock at the world's largest Sb mine, Central China

Weiqing Zhou; Peng Liu; Zhihang Ye; Bing Wen; Roger D Beckie; Aiguo Zhou; Ziyi Zhou; Jianwei Zhou

doi:10.1016/j.scitotenv.2024.171194

Antimony mobility in soil near historical waste rock at the world's largest Sb mine, Central China

Sci Total Environ. 2024 Apr 15:921:171194. doi: 10.1016/j.scitotenv.2024.171194. Epub 2024 Feb 24.

Authors

Weiqing Zhou¹, Peng Liu¹, Zhihang Ye², Bing Wen³, Roger D Beckie⁴, Aiguo Zhou², Ziyi Zhou², Jianwei Zhou⁵

Affiliations

¹ School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430074, China; Key Laboratory of Mine Ecological Effects and System Restoration, Ministry of Natural Resources, Beijing 100081, China.
² School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
³ State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China, Nanjing 210042, China.
⁴ Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020-2207 Main Mall, Vancouver, BC V6T 1Z4, Canada.
⁵ School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan 430074, China; Key Laboratory of Mine Ecological Effects and System Restoration, Ministry of Natural Resources, Beijing 100081, China. Electronic address: jw.zhou@cug.edu.cn.

PMID: 38408677
DOI: 10.1016/j.scitotenv.2024.171194

Abstract

Soil near waste rock often contains high concentrations of antimony (Sb), but the mechanisms that mobilize Sb in a soil closely impacted by the waste rock piles are not well understood. We investigated these mobility mechanisms in soils near historical waste rock at the world's largest Sb mine. The sequential extraction (BCR) of soil reveal that over 95 % Sb is present in the residual fraction. The leached Sb concentration is related to the surface protonation and deprotonation of soil minerals. SEM-EDS shows Sb in the soil is associated with Fe and Ca. Moreover, X-ray absorption spectroscopy (XAS) results show Sb is predominantly present as Sb(V) and is associated with Fe in the form of tripuhyite (FeSbO₄) as well as edge- and corner-sharing complexes on ferrihydrite and goethite. Thus, Fe in soils is important in controlling the mobility of Sb via surface complexation and co-precipitation of Sb by Fe oxides. The initially surface-adsorbed Sb(V) or co-precipitation is likely to undergo a phase transformation as the Fe oxides age. In addition, Sb mobility may be controlled by small amounts of calcium antimonate. These results further the understanding of the effect of secondary minerals in soils on the fate of Sb from waste rock weathering and inform source treatment for Sb-contaminated soils.

Keywords: Antimony; Fe oxides; Soil; Waste rock; XAS.