Retention capacity of dry soils for NAPLs

Retention capacity values were measured in the laboratory for three non-aqueous phase liquids (NAPLs), PCE, TCE and gasoline. The dry soils studied were sandy loam, clay, organic top soil and peat moss. For the conditions tested, it was determined that the retention capacity increased with an increase in the NAPL's density and the soil's porosity and a decrease in the soil bulk density. The largest observed retention capacity was for peat moss and PCE at approximately 7 gg^-1. A simple model was developed to correlate the findings and allow estimation of the retention capacity values for different soils and NAPLs. Applications of the retention capacity model are illustrated with typical examples.