Study on the Impact of Emulsion on Mine Water Quality and Health Risk Assessment

The composition of emulsion is complex. In the process of coal mining, the emulsion required by the hydraulic equipment can enter the mine water through a variety of channels, thereby affecting the water quality of the mine. In this study, the mine water of a super large coal mine, Daliuta Coal Mine, was collected, and static and dynamic simulation tests were designed to analyze the changes in various water quality indicators of mine water containing different concentrations of emulsions over time. Furthermore, the health risk assessment model was applied to evaluate the health risks of hexavalent chromium (Cr6+) and chloride in mine water containing emulsions on different populations. The results indicate that the alkaline substances such as sodium castor oil in the emulsion can increase the pH value of mine water, but it is more obvious when the emulsion concentration is high. The mine water itself contains chloride and sulfate exceeding 300 and 400 mg/L, respectively, and the addition of emulsion under static conditions has little effect on them, while the amount of emulsion added under dynamic conditions reaches 20 mL/L, which has a significant impact. The emulsion contains a certain amount of Cr6+ and can affect the total dissolved solid content, total hardness, and other indicators of mine water through mechanisms such as adsorption, solubilization, and chemical precipitation. The calculation results of the health risk assessment model indicate that the excessive chloride in the mine water in the area poses a potential non-carcinogenic risk to all populations exposed to their environment. The health risk index of Cr6+ increases with the increase in emulsion content in mine water, and the potential non-carcinogenic risk is higher for children. Overall, emulsions can significantly deteriorate the quality of mine water. This research can provide a scientific theoretical basis for subsequent study of mine water pollutant treatment, water quality monitoring and management, and health risk assessment, thereby contributing to reducing the health risks it brings and protecting the safety of local groundwater quality.