废弃煤矿矿区水污染特征及成因分析研究

ANNALYSIS ON THE CHARACTERISTICS AND CAUSES OF WATER POLLUTION IN ABANDONED COAL MINES

为揭示废弃煤矿矿井水质污染及矿井涌水机制,以四川省某煤矿为研究对象,对矿区水污染现状及成因进行研究,并结合矿井涌水机制提出针对性污染治理措施。研究结果表明,煤矿开采破坏了煤及围岩中菱铁矿和黄铁矿稳定的还原环境,硫化矿物在空气、水和细菌等共同作用下形成低pH的硫酸~硫酸高铁溶液,进而产生含有重金属等的酸性矿山涌水。单因子指数法评价表明矿区暗河、泉水总硬度、总溶解性固体(TDS)、硫酸盐、铅、锰、铝和镍指标超标;水文地质钻孔内地下水pH、总硬度、TDS、硫酸盐、氨氮、铁、铅、锰、铝和镍超标,铁、铝超标最严重,单因子指数分别达184和108;受矿井涌水污染,附近沟、河硫酸盐、铁、锰超标,单因子指数高达68.67。矿区涌水特征研究表明,2号和4号矿井涌水量较大,且对区域水环境污染贡献较大;3号矿井涌水量最大,但对区域水环境污染影响较小。对此,结合矿井涌水特点及区域水质污染机制,建议对2号和4号矿井采取封堵措施,对3号矿井进行长期监测和风险管控。研究结果为矿山涌水治理和环境污染控制提供有益参考。

In order to reveal the water quality pollution of abandoned coal mines and the mechanism of mine water gushing,a coal mine in Sichuan Province was taken as the research object to study the current situation and causes of mine water pollution,and combined with the mechanism of mine water gushing to put forward targeted pollution control measures.The research results show that the stable reduction environment of siderite and pyrite in coal and surrounding rock is destroyed by coal mining.Sulphide minerals form low pH sulfuric acid~ferric sulfate solution under the joint action of air,water and bacteria,and then produce acid mine water gushing containing heavy metals.The single factor index method shows that the total hardness,total dissolved solids(TDS),sulfate,lead,manganese,aluminum and nickel of the underground river and spring in the mining area exceed the standard.Hydrogeological borehole water pH,total hardness,TDS,sulfate,ammonia nitrogen,iron,lead,manganese,aluminum and nickel exceed the standard.Iron and aluminum exceed the standard most seriously,with single factor index reaching 184 and 108 respectively.Polluted by mine gusher,the sulfate,iron and manganese in nearby gully and river exceed the standard,and the single factor index is as high as 68.67.The study on the water gushing characteristics of mining area shows that the water gushing in No.2 and No.4 mines is large and contributes to the regional water environment pollution.No.3 mine has the largest water inflow,but it has little influence on regional water environment pollution.In this regard,combined with the characteristics of mine gushing and regional water quality pollution mechanism,it is suggested to take plugging measures for No.2 and No.4 mines,and carry out long-term monitoring and risk control for No.3 mines.The research results provide useful reference for mine water gushing treatment and environmental pollution control.