Numerical Modelling on Enhanced Mobility of Petroleum Hydrocarbon in Saturated Porous Media

Abstract

Petroleum contamination in groundwater is a widespread and well-known global environmental problem, mainly due to the leaking of aged pipelines or storage tank. The in situ treatment of petroleum hydrocarbons is relatively difficult to perform especially during pump-and-treat technique due to the trapped low-soluble hydrocarbons in the soil pores. The solubility enhancement and improved bioavailability of the small solvable portions in the petroleum products such as polycyclic aromatic hydrocarbon (PAH) can be performed by surfactants. This study aims to understand the enhanced mobility on PAH (phenanthrene) with the availability of surfactants and the associated physicochemical interactions in the saturated porous media. A 1D model is established in this regard to study the impact of surfactant on PAH enhanced solubility and subsequent transport in the saturated porous system. The hydraulic properties of soil, equilibrium partitioning and all reactions on the fate and movement of PAH are carefully included in this work. The results show that a considerable increase in the aqueous phase PAH concentration during the availability of surfactant (Triton N-101). In addition, the influence of partitioning between aqueous and solid phase, biodegradation, oxygen mass transfer are showing substantial variation on PAH transport in the saturated zone. The developed numerical model can be efficiently useful for the prediction of low-soluble organic fraction during the in situ remediation of petroleum hydrocarbon contamination.