Impact of soil factors on soil-gas partition coefficient of trichloroethylene

Objective Soil-air partitioning is a critical process influencing the environmental fate of volatile organic pollutants and a significant contributor to the risk of respiratory exposure. Methods Four typical soils-loess, red soil, black soil and sand were used to identify the soil factors affecting the partitioning of trichloroethylene. The partitioning behaviour of trichloroethylene at the soil-atmosphere interface was quantitatively investigated by single-factor controlled batch experiments, and the quantitative relationship between the trichloroethylene soil gas partition coefficient and soil factors was determined. Results The results showed significant differences in the soil-gas partition coefficients of the four typical soils (black soil>red soil>sandy soil>loess soil). The main influencing factors for the partition coefficient of black soil were primarily particle size, water content, and organic matter content. Whereas, for the other three soils, the main factors were particle size and water content. Conclusion The relationships between the soil gas partition coefficient of TCE and soil factors in black soil can be quantitatively expressed as follows: KSA=-0.744X1-0.224X2+0.704X3; sand: KSA=-0.724X1-0.222X2; loess: KSA=-0.291X1-0.268X2; and red soil: KSA=-0.589X1-0.338X2 (X1: water content; X2: particle size; X3: organic matter content). These research aids in a deeper understanding of the distribution behaviour of trichloroethylene at the soil-atmosphere interface in typical soils in China and the influence of soil factors and provide a theoretical basis for the quantification of multifactor coupling effects and health risk assessment in the process of soil gas partitioning.