A MODEL WITH MASS-TRANSPORT LIMITATIONS FOR PUMP AND TREAT REMEDIATION OF SOILS POLLUTED WITH NAPL

A model is presented for the description of the pump and treat (or flu shing) remediation of the saturated zone with non-aqueous phase liquid (NAPL) present as droplets. Sensitivity analysis shows that the most important variables are the NAPL droplet size and the distance through which the dissolved organic compound must diffuse to reach the advect ing aqueous phase. The time needed to achieve complete remediation for different initial contaminant concentrations in soil depends more on the NAPL droplet radius and the size of the stagnant boundary layer th an on the initial contaminant mass itself. Location of wells and flux rates are of little significance over the time needed for completion a s long as all the water that hows through the contaminated region is c aptured in the recovery well.