Chapter 7 - Fate, transport, and bioremediation of PAHs in experimental domain: an overview of current status and future prospects

Abstract

Soil and groundwater resource are getting contaminated at alarming rates due to human intervention. Contaminants enter in subsurface through variety of sources such as small and larger leakage or spills of fuel hydrocarbons, gasoline, and other oil products that are often stored in storage tanks (above and underground). Such leakage or spill spreads in large area under varying environmental conditions and degrade the soil and groundwater. The collective effect of dissolution, advection, and dispersion, diffusion into immobile water, adsorption onto soil matrix, volatilization, biodegradation, and other transformation processes determines the temporal evolution of hydrocarbon liquids in aquifers. When polycyclic aromatic hydrocarbons (PAHs) released in subsurface, it creates a multiphase, that is, air–water–PAHs system. In partially saturated zone, PAHs partitioning in vapor phase due to volatilization and start dissolving with pore water. Dissolution of PAHs forms plume over groundwater table and start moving due to advection. Dynamically fluctuating groundwater table and flow dynamics play significant roles in dissolution and subsequent movement of dissolved phase. Intension of this study is to present the mechanisms of fate, transport, and plant-assisted bioremediation of PAHs in experimental domain under varying subsurface conditions. Thus, a detail review is presented the knowledges and laboratory experiments performed to investigate fate and transport of PAHs in the experimental domain. This chapter will help to frame experimental investigation on different contaminations behaviors in soil–water system.