Propagation of BTEX Compounds of Gasoline in Saturated and Unsaturated Soil

BTEX compounds are light hydrocarbons in the gasoline which have attracted attention due to their long-term toxicity and deteriorating effects on the environment [1, 2]. In this study, the propagation of BTEX compounds in unsaturated and saturated zones of soil was investigated by the finite element method. The propagation of different components of BTEX was compared and the contributing factors on their propagation and transportation in water, gas and oil phases were evaluated. The results showed that when the hydraulic conductivity of the soil is high, the effect of physical properties of light hydrocarbon on extend of propagation is pronounced and the BTEX compounds propagation depth is very sensitive to the van Genuchten’s coefficient of α. Comparing the extend of propagation of BTEX compounds in different phases shows that the maximum propagation in the water and gas phases belongs to benzene and in the oil phase belongs to ethyl-benzene. The results showed that the adopted theoretical model is accurate enough to predict the propagation pattern of the light hydrocarbon contaminants in saturated and unsaturated soils.