Effect of Rate Limited Dissolution and Sorption on Concentration Tailing of Multi-component Petroleum Hydrocarbons from Residual Sources

Understanding the fate and transport mechanism of petroleum hydrocarbons (PHC) in groundwater is critical after their spill is critical towards complete removal of contaminants from the aquifer. Even though the effective solubilities of benzene, toluene, ethylbenzene and xylene (BTEX) compounds in the mixture are lower than their pure phase aqueous solubilities, they can persist in the aquifer at concentrations much above the permissible acceptance limit, as potential long-term sources for continued groundwater contamination at many sites. Numerical simulation has been carried out in the present study for a groundwater scenario with residual source containing BTEX mixtures in light of rate-limited dissolution and sorption phenomena. It was observed that due to the mass transfer constrains, the concentration elution takes tailing effect with time for the components which are more hydrophobic in nature.