采煤对浅层地下水环境的影响及矿井水生态利用分析

黄河流域中上游矿区煤?水矛盾突出，煤炭开采对地下水环境造成一定的破坏。基于此，以鄂尔多斯盆地北部侏罗纪煤田榆神府矿区为研究区，在野外调查、数据分析、室内测试的基础上，分析研究区矿井水的量质特征，揭示煤炭高强度开采对地下水环境的影响，并开展矿井水生态利用研究。结果表明:研究区矿井富水系数在0.23~2.28，平均为0.91，评估2020年区内矿井排水量高达4.70亿m3，受采掘活动影响，浅埋煤层开采区地下水位下降趋势明显；区内矿井水出现不同程度的污染组分超标现象，主要超标指标为化学需氧量(COD)、Na+、SO₄ 2?、溶解性总固体(TDS)，未处理的矿井水外排将会污染区内地下水环境；研究区浅层地下水超限的水质指标主要为NO₃-N，与矿井水超限水质指标差别较大，反映出浅层地下水水质受采矿活动影响较小；提出矿井水浅层回灌和矿井水生态灌溉2种模式开展研究区矿井水的生态利用，矿井水回灌对矿井水中的溶解性有机碳、色度具有较好的去除效果，回灌后出水满足Ⅲ类地下水限值；浅埋煤矿矿井水具有作为矿区生态修复灌溉用水的较好潜力，中深埋煤矿和深埋煤矿矿井水不适宜作为灌溉用水。研究结果为我国西部煤矿区水资源保护和生态修复提供重要依据。 

Influence of coal mining on shallow groundwater environment response to coal mining and mine water ecological utilization analysis

The contradiction between coal and water is prominent in the upper and middle reaches of the Yellow River Basin, and coal mining activities has caused certain damage to groundwater environment in those areas. So the quantity and quality characteristics of mine water for the Yushenfu mining area in Yulin City of northern Shaanxi Province were analyzed to reveal the influence of coal mining on the groundwater environment, and the ecological utilization study of mine water was also carried out based on field investigation, data analysis and laboratory tests. The results show that the mine water content coefficient in the study area ranged from 0.23 to 2.28, with an average of 0.91. In 2020, the estimated mine drainage was as high as 4.70×108 m3. The groundwater level in shallow buried mines decreased obviously affected by mining activities. The mine water quality of this area was poor, the COD, Na+, SO₄ 2?, TDS were the main factors that exceeded permitted levels, and therefore the drainage of mine water would pollute the groundwater environment. At present, the over-limit water quality index of shallow groundwater was mainly NO₃-N, which was significantly different from that of mine water, indicating that the quality of shallow groundwater in the study area was less affected by mining activities. The artificial mine water reinjection and mine water ecological irrigation were two important modes of mine water ecological utilization. The mine water reinjection had a good performance in removing of dissolved organic carbon and chroma, and the groundwater quality level meet the requirements of class III after mine water reinjection. The mine water of shallow buried mines had a good potential to be used for irrigation water for ecological restoration, but the mine water of mid-deep and deep-buried mines was not suitable as irrigation water. The results provide an important basis for water resources protection and ecological restoration in coal mining areas of western China.