Volume 32, N. 3, September-December 2009 | DOWNLOAD PDF(2 downloads)
Abstract
This work evaluates tropical soil adsorption capacity of a hydrophobic compound (benzene). With such purpose, a lateritic soil poor in organic matter and a hydromorphic soil rich in kaolinite with a higher organic content were studied. The lateritic soil, rich in Al and Fe oxides, presented a higher sorption capacity in grain size terms for having a higher clay fraction which consequently favored a greater surface contact area, and in mineralogical terms for containing micro-aggregates of Al and Fe oxides, which may confine hydrophobic compounds. This study also compared the lateritic soil retardation factor with Batch Test sorption data. It is shown that the retardation factor for benzene may overestimate the concentration of the adsorbed phase, and thus underestimates the concentration in the effective dissolved phase. Also, a simplified model is presented to calculate benzene concentration in the various phases (free, dissolved and adsorbed) and in the pore-fluid of a lateritic soil in a saturated environment.
