Influence of substrate concentration on the kinetics of olive mill wastewater biomethanation in fluid bed bioreactors using immobilized microorganisms

Abstract

A kinetic study has been made of the anaerobic olive mill wastewater fermentation process in fluid bed bioreactors containing clay supports in suspension, on which the microorganisms responsible for the process have been immobilized. Four concentrations of wastewater have been used (10%, 20%, 40% and 80%) to study the influence of the substrate concentration, and at the same time, of the immobilization support, on the biokinetic constants of the continuous process. The Chen-Hashimoto model of methane production has been applied, obtaining the values of the kinetic parameters μ_max and K for each case studied. The values of these parameters decreased considerably with increasing concentration of influent wastewater, though this decrease varied depending on the support used.