Aerobic purification of dairy wastewater in continuous regime Part II:: Kinetic study of the organic matter removal in two reactor configurations

Biokinetic equations are needed to determine net microbial growth rate or its reciprocal mean cell residence time, effluent substrate concentrations, observed yield coefficients, decay rate constants... In this paper an attempt is made to establish the kinetic parameters that describe the organic matter biodegradation process in dairy wastewaters. Two different experimental devices in continuous regime were used: a first system with a working volume of 80L, and a second system that was a series three-reactor system. Mass balances to describe the substrate utilisation rate and the microbial growth together with the kinetic models of Michaelis-Menten and Chen-Hashimoto were used to describe the process. While the first system was overloaded under the loading conditions tested, the performance of the second system could be described by the below cited kinetic models at hydraulic residence times higher than 2.3-2.4 days. (C) 2004 Elsevier B.V. All rights reserved.