Abstract

MEDINA-MORENO, S.A. et al. Biodegradation modeling of sludge bioreactores of total petroleum hydrocarbons weathering in soil and sediments. Rev. Mex. Ing. Quím [online]. 2009, vol.8, n.3, pp.245-258. ISSN 1665-2738.

A mathematical model to predict and to describe the biodegradation in sludge bioreactor of total petroleum hydrocarbons (TPHs) weathering in soil-sediments was developed and validated. The main model contribution, consisted on taking into account a hysteresis phenomena inside of the particles soil, where the initial desorption and solubilization equilibrium path of TPHs (linear isotherm) was considered to be different at the second readsorption equilibrium path (Langmuir isotherm) during intraparticle diffusivity of hydrocarbons. The Langmuir isotherm consideration, allowed explaining the retarded diffusion due to readsorption equilibrium. Model dimensionless also generate four non-dimensional numbers: bioavailability I (B_nI) and II (B_nII), Biot of mass (Bi_m) and readsorption module (η) that allowed establishing the control mechanism of the biodegradation process. The model validation was carried out by their use to describe and to predict the biodegradation of weathering TPHs in a soil with 150,000 mg/kg of contamination level. The model was also capable to describe the biodegradation of weathering TPHs from the same soil, previously treated with toluene. The model could be used as platform to develop scale-up approaches, and to improve the sludge bioreactors performance.

Keywords : diffusion-sorption-biodegradation model; sludge bioreactor; weathering total petroleum hydrocarbons; biodegradation.