PUMP-AND-TREAT REMEDIATION OF HETEROGENEOUS AQUIFERS - EFFECTS OF RATE-LIMITED MASS-TRANSFER

An analytical solution for the radial mass flux in a stratified aquifer is presented. The solution refers to a simple case of aquifer remediation by the pump-and-treat method using one extraction well. Initially, the contaminant mass is distributed between the mobile phase and ''subsurface sources,'' from which mass is transferred to the ground water by a rate-limited process. The transport of the dissolved contaminants is assumed to be by advection only. The results show that both the heterogeneity in hydraulic conductivity and the mass transfer process have impact on the predicted cleanup times. The rate of mass transfer and the mass distribution are concluded to be the most important parameters and, therefore, the mass transfer process should be the prime subject of further investigations.