Henan Key Laboratory of Coal Green Conversion, Henan Polytechnic University
School of Chemistry and Chemical Engineering,Henan Polytechnic University
Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization
School of Energy Science and Engineering, Henan Polytechnic University

Underground coal gasification (UCG) is consistent with the development of low-carbon green transformation ofenergy in China. However, the groundwater pollution caused by it is the bottleneck preventing from the promotion and applicationof UCG. Permeable reaction barrier (PRB) is one of the research hotspots for in-situ groundwater remediation. Inthis paper, combined with the characteristics of UCG with shaft, the influence of PRB’s thickness and purification materials on the migration and dispersion of organic pollutants in groundwater, and purification and remediation were investigatedby numerical simulation. On the foundation of the advection-diffusion equation (ADE), two hypotheses were introduced:① The mass transfer involved in the adsorption and purification of pollutants in groundwater is related to: (i) thedifference potential between the concentration of pollutants adsorbed in the liquid and solid phases, (ii) the difference potentialbetween the current adsorption concentration of solid phase and the potential maximum adsorption concentration,and (iii) the process time; ② The strong adsorption ability of activated carbon may lead to the gradual accumulation of adsorptionconcentration in the solid phase and no longer easy desorption with the change of the external liquid phase concentration.Both the migration of pollutants and the adsorption and purification processes were simulated numerically andvalidated experimentally after that the finite element method and theta-format iteration were adapted and the correspondingprogram were coded in MATLAB. The results show that the remediation is enhanced with the increase of the thicknessof PRB, but at a declining acceleration, and the marginal effect of the wall thickness increase on the purificationshows the diminishing trend. The stronger the adsorption and purification rate of the wall material is, the better the purificationof the PRB on pollutants will be, and the adsorption and purification rate also shows a diminishing trend of marginaleffect on the purification. There is a synergistic influence between the thickness and the adsorption activity of the material,thus the thickness of PRB should be determined reasonably according to the adsorption and purification rate of the materialwhen constructing PRB in order to obtain the best technical and economic consequence.

国家自然科学基金−新疆联合基金资助项目(U1803114)；河南省科技攻关资助项目(212102311069)

王凡，谌伦建，徐冰，等. 煤炭地下气化污染地下水的迁移与渗透反应墙净化数值模拟研究[J]. 煤炭学报，2023，48(4)：1697−1706

WANG Fan，CHEN Lunjian，XU Bing，et al. Numerical simulation on the migration and permeable reaction barrier purification of groundwater contaminated by UCG[J]. Journal of China Coal Society，2023，48(4)：1697−1706