Geochemical fingerprint and spatial pattern of mine water quality in the Shaanxi-Inner Mongolia Coal Mine Base, Northwest China

Shen Qu; Xiangyang Liang; Fu Liao; Hairu Mao; Binhu Xiao; Limin Duan; Zheming Shi; Guangcai Wang; Ruihong Yu

doi:10.1016/j.scitotenv.2022.158812

Geochemical fingerprint and spatial pattern of mine water quality in the Shaanxi-Inner Mongolia Coal Mine Base, Northwest China

Sci Total Environ. 2023 Jan 1:854:158812. doi: 10.1016/j.scitotenv.2022.158812. Epub 2022 Sep 14.

Authors

Shen Qu¹, Xiangyang Liang², Fu Liao³, Hairu Mao⁴, Binhu Xiao⁵, Limin Duan⁶, Zheming Shi⁴, Guangcai Wang⁴, Ruihong Yu⁷

Affiliations

¹ Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China.
² Xi'an Research Institute of China Coal Technology & Engineering Group Corp, Xi'an 710054, China.
³ MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China. Electronic address: fuliao@cugb.edu.cn.
⁴ MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences, Beijing 100083, China.
⁵ China coal Shaanxi Yulin Energy & Chemical Co., Ltd., Yulin 719000, China.
⁶ Water and Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China.
⁷ Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.

PMID: 36115404
DOI: 10.1016/j.scitotenv.2022.158812

Abstract

The spatial distribution of mine water quality and geochemical controls must be investigated for water safety and ecosystem protection in Shaanxi-Inner Mongolian Coal Mine Base (SICMB). Based on 122 mine water samples collected from 14 mining areas, self-organizing maps (SOM) combining with principal component analysis (PCA) derived that the mine water samples were classified into seven clusters. Clusters 1 and 3 (C1 and C3) samples were dominant by HCO₃-Ca and mixed types, which were distributed in the recharge area of the middle SICMB. In this area, the active groundwater circulation contributed to the good water quality. Cluster 2 (C2) samples were characterized by HCO₃-Na type, mainly distributed in the discharge area of the middle SICMB. These samples were threatened by heavy fluorine contamination and high residual sodium carbonate (RSC) because of slow groundwater flow in this area. Clusters 4 and 5 (C4 and C5) samples, distributed in the northeast and middle SICMB, were characterized by high Cl^- concentration and light fluorine contamination. They were influenced by anthropogenic input through faults or underground mining. In contrast, Clusters 6 and 7 (C6 and C7) samples with high salinity and sulfate were distributed in the southwest SICMB. The deep groundwater circulation enhanced water-rock interaction and contributed to poor water quality. These findings are beneficial to the management of mine water resources in the SICMB and provide an insight to investigate the mine water quality in large spatial scale.

Keywords: Hydrochemistry; Mine water; Mining area; Self-organizing map; Spatial characteristics.