Role of Biokinetic Parameters in the Methane Emission Characteristics of MBT Waste

Abstract

Biokinetic parameters have been extensively used to decide on the treatment methodology of a waste. Although literature reports studies on biokinetic parameters in wastewater treatments, their significance in the anaerobic treatment of municipal solid waste is not well explored. Furthermore, to the best of authors’ knowledge, the applicability of biokinetic parameters in estimating the gas emission characteristics of a waste have not been reported anywhere. TOUGH2 Landfill Bioreactor Model (T2LBM), a module for the TOUGH2 simulator that provides simulation capabilities for the process of biodegradation of waste governed by a modified form of Monod’s growth model, is used to investigate the same. As an initial step, numerical modeling with T2LBM is carried out to validate the gas emission characteristics of an anaerobic bioreactor that degrades a mechanically and biologically treated (MBT) waste. A good match for the gas yield and waste settlement proves the model’s capability to simulate the process of biodegradation. A parametric study of the biokinetic parameters (namely the yield coefficient, saturation constant, growth rate, and death rate of microbes) helped establish the relation of these parameters with the methane emission characteristics through Monod’s kinetics. The relation of these parameters with the methane yield is also substantiated using time-dependent variation of substrate utilization. The values of the biokinetic parameters of the MBT waste indicate the suitability of anaerobic digestion to degrade MBT waste.