Xin Lin, Xu Weihao, Niu Maofei, Feng Mingze, Yang Min, Li Hualong, Shang Zhenjie, Wang Xin
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
Key Laboratory of Ministry of Education for Mine Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
ACS Omega. 2025 Jun 17;10(25):26368-26381. doi: 10.1021/acsomega.4c09939. eCollection 2025 Jul 1.
Underground coal gasification (UCG) is a promising technique to develop coal resources efficiently and environmentally. However, contaminants generated from pyrolysis in the dry distillation channels during the UCG process have the risk of migration to the overburden, resulting in the potential contamination of groundwater. In this study, a new experiment was designed and carried out using overlying rock samples. By combining Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD) analysis, the composition of contaminants, including organic and inorganic contaminants, was identified. The migration behavior of contaminants in the overburden was revealed. The results showed that the overburden has a strong adsorption of heavy metals and porosity is an important factor affecting the migration of heavy metals. The adsorption capacity of the overburden for benzene and oxygen-containing functional group contaminants is weak, and the migration abilities of benzene and oxygen-containing functional group contaminants are approximately the same in short-range migration. The main form of benzene contaminants is pentasubstituted benzene, and changes in its relative content are negatively correlated to trisubstituted and disubstituted benzene. Oxygen-containing functional group contaminants mainly consist of alcohols, phenols, and ethers, which have strong mobility in the overburden and are the main substances in contaminants. The migration ability of Mn is the greatest among inorganic heavy-metal contaminants, followed by those of Pb, Cu, and Cd. The research provides a theoretical basis for the prevention and control of contaminants during industrial application of UCG.
地下煤气化（UCG）是一种高效、环保开发煤炭资源的有前景的技术。然而，UCG过程中干馏通道内热解产生的污染物有迁移至上覆岩层的风险，从而导致地下水潜在污染。在本研究中，利用上覆岩石样本设计并开展了一项新实验。通过结合傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）分析，确定了包括有机和无机污染物在内的污染物组成。揭示了污染物在上覆岩层中的迁移行为。结果表明，上覆岩层对重金属有较强吸附作用，孔隙度是影响重金属迁移的重要因素。上覆岩层对苯和含氧化合物官能团污染物的吸附能力较弱，苯和含氧化合物官能团污染物在短距离迁移中的迁移能力大致相同。苯污染物的主要形式是五取代苯，其相对含量的变化与三取代苯和二取代苯呈负相关。含氧化合物官能团污染物主要由醇、酚和醚组成，它们在上覆岩层中具有较强的迁移性，是污染物中的主要物质。在无机重金属污染物中，Mn的迁移能力最大，其次是Pb、Cu和Cd。该研究为UCG工业应用过程中污染物的防治提供了理论依据。
