Abstract: China has abundant coal reserves, and some mining areas contain a large amount of sulfur-containing minerals in coal and gangue. After coal seam mining, the redox conditions change, and chemical components are released and enter the water environment, causing groundwater or surface water pollution. This article is based on field testing and research data on
the chemical composition of groundwater in high sulfur coal mines in China. The potential hazard index method, comprehensive scoring method, and Hasse graphical method are combined and improved to screen for characteristic pollutants in groundwater in coal mining areas in China. The screening results show that the characteristic pollutants in acidic groundwater are Mn, Ni, Fe, Se, SO₄^2-, Al, Co, Cd, and As; The characteristic pollutants of non acidic groundwater are SO₄^2-, Mn, Ni, Fe, Pb, Co, and Cd.Among them, sulfate shows two peaks under strong acidic conditions and weak alkaline environments, especially under strong acidic conditions, with a generally high content of up to 17870 mg/L. Fe, Mn, Al, Co, Zn, and Ni are generally higher in acidic environments and gradually decrease with increasing pH, indicating that alkaline conditions are not conducive to the enrichment of these heavy metal elements in groundwater. There is a certain degree of positive correlation between the concentration of SO₄^2- in the groundwater of the mining area and the concentrations of Fe, Mn, Al, and Zn ions, indicating that some SO₄^2- and Fe, Mn, Al, and Zn ions may jointly originate from the oxidation of sulfide minerals.

Key words: high-sulfur coal mines, characteristic pollutants, groundwater, sulfates, iron, manganese