Kinetics of the biodegradation of green table olive wastewaters by aerobic and anaerobic treatments

The biodegradation of the organic pollutant matter present in green table olive wastewater (GTOW) is studied in batch reactors by an aerobic biodegradation and by an anaerobic digestion. In the aerobic biodegradation, the evolution of the substrate (in terms of chemical and biochemical oxygen demand), biomass, and total polyphenolic compounds present in the wastewater are followed during the process, and a kinetic study is performed using Contois' model, which when applied to the experimental results provides the kinetic parameter of this model, resulting in a modified Contois' equation (q = 3.3S/(0.31S(0)X + X), gCOD/gVSS d(-1)). Other kinetic parameters were determined: the cellular yield coefficient (Y-X/S = 5.7 x 10(-2) gVSS/gCOD) and the kinetic constant of cellular death phase (k(d) = 0.16 d(-1)). Similarly, in the anaerobic digestion, the evolution of the substrate digested and the methane produced are followed, and the kinetic study is conducted using a modified Monod model combined with the Levenspiel model, due to the presence of inhibition effects. This model leads to the determination of the kinetic parameters: kinetic constant when no inhibitory substance is present (k(M0) = 8.4 x 10(-2) h(-1)), critical substrate concentration of inhibition (TP* = 0.34 g/L) and inhibitory parameter (n = 2.25). (C) 2007 Elsevier B.V. All rights reserved.