Design of Permeable Adsorbing Barriers for Groundwater Protection: Optimization of the Intervention

Abstract

The remediation of polluted groundwater can be proficiently achieved with an in situ technology based on the use of Permeable Reactive Barriers (PRBs). In particular, this work deals with the design of a PAB made with activated carbon for the remediation of an aquifer contaminated by tetrachloroethylene (PCE). The design and optimization of barrier parameters (location, orientation and dimensions) were defined by an iterative procedure using a CFD (Computational Fluid Dynamics) approach, allowing the description of direction flow and dynamics of the aquifer and of the adsorption phenomena occurring inside the barrier. With the aim of optimizing the barrier, three different barrier configurations were considered, namely with constant thickness (continuous barrier, PAB-C), with sections of different thickness, tuned on pollutant inlet concentration (semi-continuous barrier, PAB-SC) and an array of deep wells (discontinuous barrier, PAB- D). The results of simulations demonstrated that an accurate selection of barrier configuration based on the shape of the pollutant plume, determines a substantial reduction of barrier volume, hence allowing a significant saving on the intervention.