Analytical solution of a pollutant transport model for unsaturated soil considering the effects of consolidation and temperature

• Published in: Journal of contaminant hydrology 2024-03, Vol.262, p.104326-104326, Article 104326
• Main Authors: Cai, Guo-qing, Yin, Feng-jie, Guo, Shi-jie, Liu, Qian-qian, Liu, Yi
• Format: Article
• Language: English
• Subjects: Consolidation; Pollutant transport; Soret coefficient; Temperature; Unsaturated soil
• ISSN: 0169-7722; 1873-6009
• DOI: 10.1016/j.jconhyd.2024.104326

The migration behavior of pollutants is affected by consolidation and temperature when using thermal desorption technology to clean contaminated sites. Based on a one-dimensional consolidation model for unsaturated soil and the traditional heat conduction equation, a pollutant transport model accounting for the combined effects of consolidation and temperature was established in this paper. An analytical solution was obtained by using the separation of variables method and the integral transformation method. In addition, the correctness of the proposed model was verified via a comparison between the existing analytical solution and the theoretical model. Finally, adopting benzene as the research object, the influence of different factors on pollutant migration was studied. It was found that the growth rate of the pollutant concentration increased with increasing consolidation pressure, and the final pollutant concentration decreased with increasing consolidation pressure. The pollutant concentration increment due to temperature first increased and then decreased with increasing migration distance. The higher the Soret coefficient and volumetric moisture content are, the higher the pollutant concentration. •The impact of consolidation on pollutant migration is mainly considered in saturated soil throughout the experimental and theoretical research results of scholars on pollutant migration, and this article mainly focuses on the influence of consolidation and temperature on pollutant migration in unsaturated soil.•Most scholars mainly focus on the relevant parameters involved in the migration process of pollutants due to temperature changes, while this article mainly explores the direct impact of temperature on pollutant migration.This article is based on the one-dimensional consolidation model of unsaturated soil proposed by Chen (1993). It is assumed that the temperature field distribution in the research domain conforms to the heat conduction equation, which convenient to reflect the direct impact of temperature field on pollutant migration field. Considering the thermal diffusion effect, establishing a mathematical model for the migration of unsaturated soil pollutants that simultaneously considers the consolidation effect and temperature effect.•The analytical solution of the model is obtained using the separation of variables method and integral transformation method. Through the analysis of the analytical solution, the consolidation effect, temperatu