Effects of Fe-rich acid mine drainage on percolation features and pore structure in carbonate rocks
Effects of Fe-rich acid mine drainage on percolation features and pore structure in carbonate rocks
复制标题
富铁酸性矿山排水对碳酸盐岩渗流特征及孔隙结构的影响
DOI：
10.1016/j.jhydrol.2020.125571
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发表时间：
2020
影响因子：
6.4
通讯作者：
Y.X. Wang
中科院分区：
文献类型：
--
作者：
Zhang X.B;J. Guo;Q.H. Hu;X.B. Gao;C.C. Li;M. Luo;Y.X. Wang
酸性矿井水（AMD）在世界范围内对生态、环境和地质造成了重大挑战，特别是在喀斯特脆弱地区。然而，AMD对渗流特征和孔隙的影响。碳酸盐岩地层结构对碳酸盐岩含水层的演化具有重要意义，但人们对其了解甚少。以及岩溶地下水质量。为了填补这一知识空白，实地调查，岩心驱油实验，。反应输运模型和孔隙结构研究[汞侵入孔隙法（MIP）和氮]。通过物理吸附分析来了解地球化学过程和相应的孔隙发育。暴露于富铁AMD的碳酸盐地层中。我们的实地调查表明AMD是有特征的。pH值低（2.4 ~ 3.8），硫酸盐含量高（1457 ~ 4217 mg/L），铁含量高（100 ~ 830 mg/L, Fe3+/Fe2+），重金属，可能会渗入碳酸盐地层。本研究的主要发现包括：(1)岩心驱替。实验表明，碳酸盐岩与AMD的相互作用导致了溶液的快速抬升。pH和同时析出的Fe3+/Fe2+作为铁（氧）氢氧化物或（氧）羟基硫酸盐在岩石中；(2)反应输运模拟结果表明，亚铁的输运距离比铁的输运距离长。三铁在碳酸盐岩心中堵塞，然后沉淀，填充孔隙空间；(3)尽管有降水，AMD的驱油通过创造大量孔隙来增加岩心的整体渗透率。喉道直径在0.001 ~ 10 μm之间。我们还发现了AMD与碳酸盐的相互作用。岩石可能会刺激优先流道的形成。我们的结果已被纳入一个概念模型，用来说明所涉及的地球化学过程和机制。我们的研究。在煤矿行业的AMD治疗以及地方政府制定策略方面的重要应用。用于岩溶水资源的保护和管理。
Acid mine drainage (AMD) poses significant ecological, environmental and geological challenges worldwide,.especially in more vulnerable karst areas. However, the impact of AMD on percolation features and pore.structure of carbonate strata is poorly understood, despite its importance for the evolution of carbonate aquifer.as well as karst groundwater quality. To fill this knowledge gap, field investigations, core-flooding experiments,.reactive transport modeling and pore structure studies [mercury intrusion porosimetry (MIP) and nitrogen.physisorption analysis] were conducted to understand the geochemical processes and associated pore development.in carbonate strata exposed to Fe-rich AMD. Our field investigation shows that the AMD is characterized.by low pH values (2.4–3.8), high contents of sulfate (1457–4217 mg/L), Fe (100–830 mg/L, Fe3+/Fe2+) and.heavy metals, that can potentially leak into carbonate strata. The major findings of this study include: (1) coreflooding.experiments reveal that the interaction of carbonate rock with AMD causes a rapid elevation of solution.pH and simultaneous precipitation of Fe3+/Fe2+ as iron (oxy)hydroxides or (oxy)hydroxy sulfates within the.rock; (2) the results of reactive transport modeling suggest that ferrous iron has a longer transport distance than.ferric iron in the carbonate core plug, and then it precipitates to fill the pore space; and (3) despite the precipitation,.the flooding of AMD increases the overall permeability of cores by creating large numbers of pores.with throat diameter between 0.001 and 10 μm. We also found that the interaction of AMD with the carbonate.rock might stimulate the formation of preferential flow channel(s). Our results have been incorporated into a.conceptual model, built to illustrate the geochemical processes and mechanisms involved. Our research has.important applications in AMD treatment for coal-mining industries, and for local governments devising strategies.for karst water resource protection and management.