School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, China; Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region, Henan Province, Jiaozuo 454000, China; Key Laboratory of Mine Geological Hazards Mechanism and Control, Xi'an 710054, China.
School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, China; Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region, Henan Province, Jiaozuo 454000, China; Key Laboratory of Mine Geological Hazards Mechanism and Control, Xi'an 710054, China.
J Contam Hydrol. 2019 Jun;223:103473. doi: 10.1016/j.jconhyd.2019.03.005. Epub 2019 Apr 1.
Although the technology of coal mine underground reservoirs has been widely applied in the Western China, little is known about the variation of water quality induced by the removal transformation of nitrogen and dissolved organic matter (DOM) rich in mine water during its storage and transport in a coal mine underground reservoir. Column experiments were carried out at 30 °C and at Darcy fluxes ranging from 0.32 cm/h to 0.64 cm/h to investigate the transport parameters and dynamic changes of nitrogen and DOM in a simulated underground reservoir filled with coal gangue, which was composed of sandstone and mudstone. Results showed that chloride transport could be described by the convection-dispersion equation (CDE) well at a Darcy flux of 0.32 cm/h, wherein the dispersion role was obvious. Despite the high level of nitrite in the influent, the effluent concentrations of nitrite and nitrate fluctuated around the background values through complete denitrification. And the removal of total nitrogen (TN) with efficiencies between 55.1% and 76% were highly correlated with nitrite denitrification. Ammonification of organic nitrogen got weakened over time and the content of ammonium ion tended to be stable at the level of that in the input mine water. The delayed breakthrough curves of chemical oxygen demand (COD) and dissolved organic carbon (DOC) at a Darcy flux of 0.32 cm/h could be attributed to their adsorption onto the coal gangue during their transport through the simulated underground reservoir. Due to the variations of microbial and compositions of the input mine water, the removal efficiencies of COD and DOC increased slightly from 62% to 68%, 56% to 63%, respectively, when the Darcy flux increased from 0.32 cm/h to 0.62 cm/h. The findings would be helpful in evaluating the effectiveness of post-treatment of mine water during its storage in an underground reservoir in coal mine areas of Western China.
虽然煤矿地下水库技术已在西部地区得到广泛应用，但对于富含氮和溶解有机物（DOM）的煤矿水中这些物质在地下水库储存和运输过程中发生的去除转化导致的水质变化知之甚少。为此，在 30°C 下进行了柱实验，达西流速从 0.32cm/h 到 0.64cm/h 不等，以研究由砂岩和泥岩组成的模拟煤矿地下水库中煤矸石的氮和 DOM 的输运参数和动态变化。结果表明，在达西流速为 0.32cm/h 时，氯的迁移可以用对流弥散方程（CDE）很好地描述，其中弥散作用很明显。尽管进水的亚硝酸盐含量很高，但通过完全反硝化作用，出水的亚硝酸盐和硝酸盐浓度在背景值附近波动。总氮（TN）的去除率在 55.1%到 76%之间，与亚硝酸盐反硝化密切相关。随着时间的推移，有机氮的氨化作用减弱，铵离子的含量趋于稳定在进水的水平。达西流速为 0.32cm/h 时，化学需氧量（COD）和溶解有机碳（DOC）的迟后穿透曲线可归因于它们在通过模拟地下水库时被煤矸石吸附。由于输入煤矿水中微生物和组成的变化，当达西流速从 0.32cm/h 增加到 0.62cm/h 时，COD 和 DOC 的去除效率分别从 62%略微增加到 68%、56%略微增加到 63%。这些发现将有助于评估中国西部煤矿区地下水库储存过程中煤矿水处理的效果。
