Design of remediation process for volatile organic pollution sites with air sparging based on TOUGH2

The air sparging method is a crucial technology for addressing organic contamination in groundwater and soil. When integrated with numerical simulation, this approach allows for the optimization of remediation conditions, thereby enhancing the effectiveness of the remediation process. This paper utilized the T2VOC module of TOUGH2 software, to simulate and investigate the transport mechanisms of para-xylene during the processes of leakage, redistribution, and air sparging remediation within a specified study area. The findings of this research indicated that during the leakage of contaminants, para-xylene in the unsaturated zone underwent vertical migration and lateral expansion due to the combined effects of gravitational and capillary forces. In contrast, para-xylene in the saturated zone primarily experienced horizontal diffusion and subsequently dissolved into the groundwater, which complicated the spread of contamination. Furthermore, by taking the specific site conditions of the study area into account, including soil permeability and groundwater level, this study identified the optimal aeration flow rate at 12 m³/h and the aeration depth at 10.4 m. These results provide significant insights into the behavior of para-xylene contaminants and contribute to the development of more effective remediation strategies for contaminated sites. Overall, this research highlighted the importance of integrating numerical modeling with traditional remediation techniques, offering a promising direction for improving the management of organic pollutants in subsurface environments. Thus, it lays a foundational understanding for future studies aimed at refining remediation practices and addressing environmental challenges related to soil and groundwater contamination.