Mine Water Source Discrimination Based on Hydrogeochemical Characteristics in the Northern Ordos Basin, China

Sudden inrushes of mine water from coal roofs threaten the safe production of coal in China’s northern Ordos Basin. However, due to similar hydrochemical characteristics, routine hydrochemical analysis fails to discriminate the water sources. In this study, a new method, based on the characteristics of dissolved organic matter (DOM), the major inorganic constituents, and environmental isotopes was used to discriminate mine water sources. It turns out that the total dissolved solids concentration is less than 560.0 mg/L in the shallow aquifer and surface water, but exceeds 1000 mg/L in the deep aquifers. The concentrations of deuterium (D) and oxygen isotope (18O) gradually decrease in the Quaternary, Cretaceous, and Jurassic aquifers, and with increased burial depth, the age of groundwater increases. The surface water and underground aquifers differ with respect to the concentration, type, fluorescence intensity, and fluorescence regional integral of DOM. The DOM concentration and the fluorescent parameter values both generally decrease with increased burial depth. Comprehensive analysis of DOM, inorganic constituents, and environmental isotopes in water samples can be used to distinguish water sources, which may help prevent and control mine water hazards in the study area.