Elucidating the hydrochemistry and REE evolution of surface water and groundwater affected by acid mine drainage

• 全文链接
• 请求原文

作   者：

Shi X.;  Gao Y.;  Qian H.;  Chen J.;  Li W.;  Li S.;  Liu Y.; 

作者机构：

School of Water and Environment Chang'an University||Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education Chang'an University||Key Laboratory of Eco-hydrology and Water Security in Arid and Semi-arid Regions of the Ministry of Water Resources Chang'an University;  School of Water and Environment Chang'an UniversitySchool of Water and Environment Chang'an UniversitySchool of Water and Environment Chang'an University||Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of the Ministry of Education Chang'an University||||Key Laboratory of Eco-hydrology and Water Security in Arid and Semi-arid Regions of the Ministry of Water Resources Chang'an University||; 

关键词：

Hydrochemical evolution;  REE;  Potentially toxic elements;  Pyrite mine;  Surface and groundwater; 

期刊名称：

Environmental Pollution

i s s n：

0269-7491

年卷期：

2025 年 366 卷 Feb.1 期

页   码：

1.1-1.13

页   码：

摘   要：

© Elsevier LtdThe impact of pyrite mining on water quality is a global concern. This study investigates the impact of acid mine drainage (AMD) from an abandoned pyrite mine in the Qinling Mountains on surface and groundwater hydrochemistry and rare earth elements (REEs) evolution. A total of 54 water samples were collected in 2021, of which the Muzi River downstream of the mining area was repeated three times in three sampling periods. Hydrogeochemical methods and stable isotope techniques were used to analyze the impacts of AMD. Results showed that tailing water in comparison to groundwater and surface waters exhibits low pH with high concentrations of SO42, potentially toxic elements (PTEs), and REEs, and is characterized by normalized middle REE (MREE) enrichment. Groundwater is less influenced by AMD and shows HCO3-Ca and HCO3-Ca·Na types. AMD contaminates surface water to different degrees. Surface water received SO42 input from AMD, exhibited SO4-Ca, SO4·HCO3-Ca, and HCO3·SO4-Ca types within the mining area, and evolved from HCO3·SO4-Ca to HCO3-Ca downstream as AMD influence diminishes. High concentrations of PTEs and REEs are presented in AMD and seepage near the slag heap, and decreased rapidly along the flow path, while SO42 migrated over longer distances. The water in the study area primarily originates from atmospheric precipitation, with close relation among surface water, groundwater, and tailing water. Water-rock interactions and pyrite oxidation governed the hydrochemical composition, with sulfide oxidation facilitated the carbonatite-water reaction, which alleviated sulfide oxidation-induced acidification. The concentrations of PTEs are regulated by adsorption and precipitation, carbonate buffering, and dilution along the flow path. REEs are mainly controlled by pH, inorganic complexation, and secondary mineral adsorption. As the pH changes from acidic to neutral or weakly alkaline, REEs shift from sulfate-complex dominated to carbonate-complex dominated. These insights contribute to a better understanding of AMD impacts on surface and groundwater, providing a basis for the rational management of AMD.