Physico-chemical processes affecting the bioavailability of PAHs

The effect of mass transfer limitations on the biodegradation of naphthalene and phenanthrene is studied in defined systems, as to study the processes that determine the limited bioavailability of polycyclic aromatic hydrocarbons (PAHs) in soil. Bioavailability of PAHs was shown to be limited by film diffusion for crystalline substrates and by intraparticle diffusion for contaminated porous matrices, resulting in submaximal biodegradation rates. The effect of limitations in the mass transfer processes were quantified and modeled mechanistically, using mass transfer coefficients and microbiological kinetics.