Modeling the Temperature Kinetics of Aerobic Solid-State Biodegradation

Abstract

This study evaluated three models of microbial temperature kinetics using CO2 respiration data from aerobic solid-state biodegradation experiments. The models included those of Andrews and Kambhu/Haug, Ratkowsky et al., and the Cardinal Temperature Model with Inflection (CTMI) of Rosso et al. A parameter estimation routine implemented the Complex-Box search method for each model on 48 data sets collected during the composting of synthetic food waste or sewage-sludge (biosolids) mixed with maple wood chips at different oxygen concentrations and extents of decomposition. Each of the three nonlinear temperature kinetic functions proved capable of modeling a wide range of experimental data sets. However, the models differed widely in the consistency of their parameters. Parameters in the CTMI model were more stable over the course of the degradation process, and that variability which did arise was directly related to changes in the microbial process. Additional benefits of the CTMI model include the ease of parameter determinations, which can be approximated directly from laboratory experiments or full-scale system analysis, and the direct value of its parameters in engineering design and process control under a wide range of biodegradation conditions.