Assessment of the Impact of Abandoned Mine Water on Groundwater Environment

The assessment of the impact of abandoned mine water on the underwater environment is critical for protecting and restoring the groundwater environment. Taking the abandoned coal mining area in the west of Zhangqiu District as the engineering background and comprehensively considering the regional groundwater chemical characteristics data during the wet and dry seasons, the main characteristics of the ions, hydrochemical types, and ion correlations of the abandoned mine water with the regional groundwater components were analyzed using mathematical statistics, correlation analysis, and Piper diagrams. An impact assessment was conducted on the water quality index values of the groundwater monitoring point. Furthermore, this research establishes an evaluation method of abandoned mine water in a regional groundwater environment based on the improved Nemero index method and matter element theory. Overall, the groundwater pH is weakly alkaline in Zhangqiu District. The groundwater Ca2+ is the dominant cation, while HCO3- and SO42- are the dominant anions. The main ion concentration during the dry season is slightly greater than during the wet season. The main hydrochemical type of groundwater during the wet and dry seasons is HCO3-Ca. In addition, there is a correlation between NO3- and F-, which may be caused by human activities. The groundwater environment is classified as level IV and severely polluted.