Chen Sisi, Fang Gang, Wang Lei, Chen Yingbo, Ji Yao, Meng Chaoyang, Yu Hongyan
State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
School of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China.
ACS Omega. 2024 May 16;9(21):22532-22542. doi: 10.1021/acsomega.3c05562. eCollection 2024 May 28.
The hydrochemical characteristics of groundwater are of great significance for studying the source, development, and utilization of groundwater. This study investigated the characteristics of anions and cations, total dissolved solids (TDS), hydrochemical types, and hydrogen and oxygen isotopes of surface water and groundwater in the Balasu coalfield. By conducting experiments using inductively coupled plasma emission electron spectrometry, ion chromatography, acid-base titration, and gravimetric analysis, the characteristics of ion concentration and TDS in different aquifers were analyzed to determine the possible source of groundwater in C2 (number 2 coal seam in Yan'an Formation). The Piper trilinear diagram was used to determine the hydrochemical types of aquifers, and the source of groundwater was determined based on the stable isotope characteristics of hydrogen and oxygen. The changes in ion, TDS, hydrogen, and oxygen isotopes of surface water and groundwater were analyzed, and the groundwater differences between the two sets of coal seams were compared. The research results indicate that the groundwater in C2 (number 2 coal seam in Yan'an Formation) is caused by the original sedimentary water and the infiltration of Zhiluo Formation and A1 (strata at the top of the Yan'an Formation to number 2 coal seam). However, C4 (number 3 coal seam in Yan'an Formation) is hindered by the well-developed mudstone in A3 (bottom of number 2 coal seam to the top of number 3 coal seam), which hinders the infiltration of groundwater. The study emphasizes that the overlying strata can have a significant impact on the coal seam when the moisture content is high and there is a lack of overlap, thereby promoting changes in the moisture content of the coal seam. This study provides some insights into the safety of coal mines, especially in mining areas with a high coal seam moisture content.
地下水的水化学特征对于研究地下水的来源、发育和利用具有重要意义。本研究调查了巴喇苏煤田地表水和地下水的阴离子和阳离子特征、总溶解固体（TDS）、水化学类型以及氢氧同位素。通过电感耦合等离子体发射电子光谱法、离子色谱法、酸碱滴定法和重量分析法进行实验，分析了不同含水层中离子浓度和TDS的特征，以确定延安组2号煤层（C2）地下水的可能来源。采用派珀三线图确定含水层的水化学类型，并根据氢氧稳定同位素特征确定地下水的来源。分析了地表水和地下水的离子、TDS、氢氧同位素的变化，并比较了两组煤层之间的地下水差异。研究结果表明，延安组2号煤层（C2）的地下水是由原生沉积水以及直罗组和延安组顶部至2号煤层（A1）的渗入水形成的。然而，延安组3号煤层（C4）受到延安组2号煤层底部至3号煤层顶部（A3）发育良好的泥岩的阻碍，这阻碍了地下水的渗入。该研究强调，当含水量高且缺乏重叠时，上覆地层会对煤层产生重大影响，从而促进煤层含水量的变化。本研究为煤矿安全，特别是煤层含水量高的矿区的安全提供了一些见解。
