松宜地区煤矿酸性废水(AMD)形成机制研究

Study on formation mechanism of acid mine drainage(AMD)in Songyi area

松宜矿区煤炭开采历史悠久,矿区内各煤矿均已陆续停产闭坑。在煤矿长期开采过程中,山体内部形成了大面积采空区,严重破坏了区内原始水文、工程、环境地质条件,致使在现有地质条件中产生了一系列新的环境问题,主要表现为废弃煤矿的酸性废水污染。2017年,松宜地区尖岩河煤矿发生了酸水污染事件,对当地环境产生了严重影响。为进一步研究煤矿酸性废水的形成机理,通过调查松宜矿区的水文地质条件,岩层的含水性、地下水补径排特征、地表水、地下水动态变化特征,以及对水化学形成机制、水动力学形成机制、污染成因、时序污染模式等进行相关分析,同时对该区域内的地表水进行了取样化验。结果表明,煤矿酸性废水的排放是研究区地表水体污染的主要原因,而水质混合试验又说明串层污染是研究区域内煤矿酸性废水形成的重要因素。从水文地质、环境化学等方面对煤矿酸性废水的形成机制进行探索,研究可为其他煤矿剖析提供借鉴。

Songyi mining area with a long history of coal mining,all coal mines in Songyi mining area have stopped production and closed pits.In the long-term mining process of coal mines,a large area of goaf has been formed inside the mountain,which has seriously damaged the original hydrological,engineering and environmental geological conditions in the area,resulting in a series of new environmental problems under the existing geological conditions,mainly manifested in the abandoned AMD pollution.In 2017,an acid water pollution incident occurred in Jianyanhe Coal Mine in Songyi mining area,which had a serious impact on the local environment.In order to further study the formation mechanism of acid wastewater in coal mines,this paper investigated the hydrogeological conditions in Songyi mining area,including the water content of rock strata,the characteristics of groundwater recharge and drainage,the dynamic change characteristics of surface water and groundwater,and analyzed the hydrochemical formation mechanism,hydrodynamic formation mechanism,pollution causes and time-series pollution mode,and sampled the surface water in this area.The results show that the discharge of AMD is the main cause of surface water pollution in the study area,and the water quality mixing test shows that cascade pollution is an important factor for the formation of AMD in the study area.The formation mechanism of AMD is explored from the aspects of hydrogeology and environmental chemistry,and the research results can provide some reference for other coal mines.