MODELING OF DENSE NONAQUEOUS PHASE LIQUID REMOVAL FROM AQUIFERS BY SPARGING AND PUMP-AND-TREAT OPERATIONS

Microcomputer programs for modeling the removal of dense nonaqueous ph ase liquid (DNAPL) droplets and ganglia from aquifers by pump-and-trea t operations and sparging techniques are described and results obtaine d with these programs are presented. The programs permit the modeling of diffusion-limited mass transport from the stationary DNAPL ganglia to the advecting aqueous phase; diffusion transport is assumed to take place from DNAPL droplets through a thick stagnant water layer in a p orous medium to the advecting mobile water. The dependence of DNAPL re moval rates on the various model parameters (i.e., DNAPL aqueous solub ility, Henry's constant, diffusion constant, droplet size; air and wat er flow rates; system geometrical parameters) is discussed.