Mechanisms of Natural Toluene Attenuation in Btex-Contaminated Groundwater

Abstract

Natural attenuation that follows first-order kinetics occurs in groundwater contaminated by BTEX monoaromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes). Various mechanisms such as adsorption, biodegradation, volatilization, dilution, convection, etc. can contribute to the attenuation. The contribution of each mechanism to the overall toluene attenuation process was assessed. It was established that adsorption played the most important role and was followed by dilution, convection, diffusion, and other effects. The contribution of volatilization was not as significant at 1.78%; of biodegradation, 3.34%.