Using Granular Dead Anaerobic Sludge as Permeable Reactive Barrier for Remediation of Groundwater Contaminated with Phenol

Abstract

The possibility of using granular dead anaerobic sludge (GDAS) biosorbent as a permeable reactive barrier (PRB) to remove phenol from contaminated shallow groundwater was investigated. Batch tests were performed to characterize the equilibrium sorption properties of GDAS and sandy soil in phenol-containing aqueous solutions. The Langmuir isotherm model gives a better fit for the sorption data of phenol by GDAS and soil than other models under the studied conditions. One-dimensional column experiments were performed at a pilot scale, and an integrated model based on the solution of an advection-reaction-dispersion mass balance equation, using the finite-element method, was developed to study the space and time normalized concentration of phenol within groundwater. Numerical and experimental results proved that the PRB plays a potential role in the restriction of the contaminant plume migration. Also, these results showed that the removal of phenol by PRB was increased as function of its thickness and that the barrier starts to saturate with contaminant as a function of the travel time. However, a good agreement between the predicted and experimental results was recognized with the root-mean squared error (RMSE) not exceeding 0.0460 and Nash-Sutcliffe efficiency not less than 0.9201.