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

An analytical solution for the radial mass flux in a stratified aquife r is presented. The solution refers to a simple case of aquifer remedi ation by the pump-and-treat method using one extraction well. Initiall y, the contaminant mass is distributed between the mobile phase and '' subsurface sources,'' from which mass is transferred to the ground wat er by a rate-limited process. The transport of the dissolved contamina nts 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 para meters and, therefore, the mass transfer process should be the prime s ubject of further investigations.