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Zhang W, Duan L, Yinglan A, Xue B, Wang G, Liu T. Hydrogeochemical evolution patterns of diverse water bodies in mining area driven by large-scale open-pit combined underground mining-taking Pingshuo Mining Area as an example. JOURNAL OF CONTAMINANT HYDROLOGY 2024; 267:104420. [PMID: 39270600 DOI: 10.1016/j.jconhyd.2024.104420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 08/18/2024] [Accepted: 08/31/2024] [Indexed: 09/15/2024]
Abstract
Large-scale open-pit combined underground mining activities (OUM) not only reshape the original topography, geomorphology, and hydrogeochemical environment of the mining area, but also alter the regional water cycle conditions. However, due to the complexity arising from the coexistence of two coal mining technologies (open-pit and underground mining), the hydrological environmental effects remain unclear. Here, we selected the Pingshuo Mining Area in China, one of the most modernized open-pit combined underground mining regions, as the focus of our research. We comprehensively employed mathematical statistics, Piper diagram, Gibbs model, ion combination ratio, principal component analysis and other methods to compare the hydrochemistry and isotope data of different water bodies before (2006) and after (2021) large-scale mining. The changing patterns of hydrochemical characteristics of different water bodies and their main controlling factors in mining area driven by OUM were analyzed and identified, revealing the water circulation mechanism under the background of long-term coal mining. The results showed that: (1) The chemical composition of water has changed greatly due to large-scale coal mining. The hydrochemical types of Quaternary and Permian-Carboniferous aquifers shifted from predominantly HCO3-Ca·Mg before intensive mining to primarily HCO3·SO4-Ca·Mg, HCO3-Na, HCO3·SO4-Na·Mg, and HCO3·SO4-Ca·Mg, HCO3-Ca·Na, HCO3·SO4-Mg·Ca post-mining. Variations in the hydrochemical types of surface water were found to be complex and diverse. (2) Coal mining activities promote the dissolution of silicate rock and sodium-bearing evaporites, enhancing the strength and scale of positive alternating adsorption of cations. The oxidation of pyrite, dissolution of silicate weathering, and the leaching of coal gangue were identified as the main reasons for the significant increase of SO42-, while decarbonation in confined aquifers led to a decrease in HCO3-. (3) Results from the principal component analysis and stable isotopes demonstrated the hydraulic connection among surface water, Quaternary aquifers, and Permian-Carboniferous aquifers induced by long-term OUM. The research findings provide a reference basis for the coordinated development of coal and water in the Pingshuo Mining Area and other open-pit combined underground mining areas.
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Affiliation(s)
- Wenrui Zhang
- The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot 010018, China; Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot 010010, China
| | - Limin Duan
- The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot 010018, China; Autonomous Region Collaborative Innovation Center for Comprehensive Management of Water Resources and Water Environment in the Inner, Mongolia Section of the Yellow River Basin, Hohhot 010018, China.
| | - Yinglan A
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
| | - Baolin Xue
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
| | - Guoqiang Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
| | - Tingxi Liu
- The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot 010018, China; Autonomous Region Collaborative Innovation Center for Comprehensive Management of Water Resources and Water Environment in the Inner, Mongolia Section of the Yellow River Basin, Hohhot 010018, China.
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Jiang C, Jiang C, Wang Q, Liu H, Li D, Zhu Q, Liu F. Seasonal characteristics of groundwater discharge controlled by precipitation and its environmental effects in a coal mining subsidence lake, eastern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:170067. [PMID: 38242470 DOI: 10.1016/j.scitotenv.2024.170067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 01/21/2024]
Abstract
Many regions have formed subsidence lakes due to underground mining in the world. However, seasonal variations of lacustrine groundwater discharge (LGD) rate and solute fluxes in the coal mining subsidence were rarely reported. In this study, we conducted four seasonal samplings in a coal mining subsidence, during which samples for stable water (δ18O) and radioactive (222Rn) isotopes were collected to quantify the seasonal dynamics of LGD rates. The LGD rates estimated from the 222Rn mass balance model were 10.2 ± 8.7, 5.5 ± 3.2, 11.5 ± 7.8, and 7.8 ± 4.5 mm d-1 in summer, autumn, winter and spring, respectively. According to the 18O mass balance model, the corresponding LGD rates were 15.1, 7.3, 15.6, and 11.3 mm d-1 in summer, autumn, winter and spring, respectively. We found a significant correlation between precipitation and LGD rates, suggesting precipitation was recognized as the main control factor for seasonal variations of LGD rates. Based on this correlation, the extrapolated LGD rates over a year ranged from 3.1 to 12.7 mm d-1 with an average of 8.8 mm d-1. Moreover, the fluxes of dissolved silicon (DSi), iron (Fe), and manganese (Mn) from LGD in autumn were (1.6 ± 0.9) × 105, (1.9 ± 1.1) × 104, and (1.1 ± 0.6) × 104 mol a-1, respectively. Correspondingly, in winter they were (3.5 ± 2.4) × 105, (4.1 ± 2.8) × 103, and (2.8 ± 1.9) × 103 mol a-1, respectively. This study demonstrated significantly seasonal variations of LGD, with precipitation being the main control factor of LGD in the coal mining subsidence lake. The fluxes of dissolved substance (DSi, Fe, Mn) from LGD need to be emphasized because they may have important impacts on the ecological stability in coal mining subsidence lakes.
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Affiliation(s)
- Chenghong Jiang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China
| | - Chunlu Jiang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China; School of Resources and Geoscience, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
| | - Qianqian Wang
- Department of Earth Science, The University of Hong Kong, Hong Kong, China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
| | - Hui Liu
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China
| | - Desheng Li
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China
| | - Qiyu Zhu
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China
| | - Feng Liu
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui, China
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Jiang C, Li M, Li C, Huang W, Zheng L. Combining hydrochemistry and 13C analysis to reveal the sources and contributions of dissolved inorganic carbon in the groundwater of coal mining areas, in East China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:7065-7080. [PMID: 37572235 DOI: 10.1007/s10653-023-01726-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 08/04/2023] [Indexed: 08/14/2023]
Abstract
East China is a highly aggregated coal-grain composite area where coal mining and agricultural production activities are both flourishing. At present, the geochemical characteristics of dissolved inorganic carbon (DIC) in groundwater in coal mining areas are still unclear. This study combined hydrochemical and carbon isotope methods to explore the sources and factors influencing DIC in the groundwater of different active areas in coal mining areas. Moreover, the 13C isotope method was used to calculate the contribution rates of various sources to DIC in groundwater. The results showed that the hydrochemical types of groundwater were HCO3-Ca·Na and HCO3-Na. The main water‒rock interactions were silicate and carbonate rock weathering. Agricultural areas were mainly affected by the participation of HNO3 produced by chemical fertilizer in the weathering of carbonate rocks. Soil CO2 and carbonate rock weathering were the major sources of DIC in the groundwater. Groundwater in residential areas was primarily affected by CO2 from the degradation of organic matter from anthropogenic inputs. Sulfate produced by gypsum dissolution, coal gangue accumulation leaching and mine drainage participated in carbonate weathering under acidic conditions, which was an important factor controlling the DIC and isotopic composition of groundwater in coal production areas. The contribution rates of groundwater carbonate weathering to groundwater DIC in agricultural areas and coal production areas ranged from 57.46 to 66.18% and from 54.29 to 62.16%, respectively. In residential areas, the contribution rates of soil CO2 to groundwater DIC ranged from 51.48 to 61.84%. The results will help clarify the sources and circulation of DIC in groundwater under the influence of anthropogenic activities and provide a theoretical reference for water resource management.
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Affiliation(s)
- Chunlu Jiang
- School of Resources and Geoscience, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China.
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, Anhui, China.
| | - Ming Li
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, Anhui, China
| | - Chang Li
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, Anhui, China
| | - Wendi Huang
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, Anhui, China
| | - Liugen Zheng
- School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, Anhui, China
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