Sources and mixing of sulfate contamination in the water environment of a typical coal mining city, China: evidence from stable isotope characteristics

• Published in: Environmental geochemistry and health 2020-09, Vol.42 (9), p.2865-2879
• Main Authors: Chen, Xing, Zheng, Liugen, Dong, Xianglin, Jiang, Chunlu, Wei, Xiangping
• Format: Article
• Language: English
• Subjects: Coal; Coal mines; Coal mining; Contamination; Dissolution; Dissolving; Earth and Environmental Science; Eigenvalues; Environment; Environmental Chemistry; Environmental Health; Evaporites; Gangue; Geochemistry; High flow; Isotopes; Leaching; Low flow; Mine drainage; Mining; Original Paper; Oxygen isotopes; Public Health; River water; Rivers; Rock; Rocks; Seasonal variation; Seasonal variations; Seasons; Soil Science & Conservation; Stable isotopes; Subsidence; Sulfates; Sulfur; Sulphur; Surface water; Terrestrial Pollution; Water analysis; Water pollution; Water sampling; Water supply
• ISSN: 0269-4042; 1573-2983
• DOI: 10.1007/s10653-020-00525-2

To explore the sources and distribution characteristics of SO 4 2− in the surface waters of the Linhuan mining area in Huaibei, river and surface water samples in subsidence and mine drainage locations in the study area were collected at different times. The conventional hydrochemical indexes and the eigenvalues of sulfur and oxygen isotopes were tested and analyzed. The results suggested the following: (1) The SO 4 2− content showed seasonal changes: low-flow seasons > mid-flow seasons > high-flow seasons. (2) Based on δ 34 S SO4 and δ 18 O SO4 isotope analyses, the main source of SO 4 2− was the dissolution of evaporite salt rocks in the stratum of the upstream area. The SO 4 2− in the subsidence area was mainly from the river water supply, mine drainage and coal gangue leaching. The high concentration of SO 4 2− in the mine drainage was mainly from the dissolution of evaporative salt rocks. (3) The calculation results of the ternary mixing model showed that the SO 4 2− in the subsidence area water was affected by mine drainage and gangue leaching to different degrees. The results showed that the sulfate contribution proportion of the river water source to the subsidence area water was 35.8–65.9%; the sulfate contribution proportion of the mine drainage source to the subsidence area water was 2.0–26.6%; and the sulfate contribution proportion of the gangue leaching end source ranged from 16.3% to 56.9%. Coal mining activities had an important impact on the sulfate in the subsidence area water.