A mathematical model was developed to simulate the biodegradation of municipal solid waste (MSW) in bioreactor landfills operating under saline conditions and to predict the leachate strength (aqueous organic and volatile fatty acid (VFA)), and the volume of landfill gas (CH4 and CO 2) produced. The model described the biodegradation of MSW into methane and carbon dioxide in three steps. These steps were hydrolysis, acidogenesis, and methanogenesis. The hydrolysis step was assumed to follow first order kinetics whereas the Monod kinetics were used to describe the growth rate of acidogenic and methanogenic biomass. The inhibition of salt content was linked to the hydrolysis rate constant and methanogenic bacteria. A competitive inhibition term to simulate the effect of saline environment was included in the Monod kinetics to simulate the methanogenic biomass. Sensitivity analysis indicates that the hydrolysis rate constant, methanogenic kinetics (μM, kdM, KSM), and initial concentration of methanogenic biomass had a significant impact on peaks of the VFA and daily methane produced, as well as the time required to reach them. The model has been calibrated by comparing the simulation results to experimental 1D bioreactor measurements. The results of methane production showed good agreement between the model and experimental data. Both the model kinetics and the fitting parameters for salt inhibition (K, and m) were determined from these simulations.

Additional Metadata
Keywords Bioreactor landfill, Mathematical model, Methane production, Salinity
Conference Annual Conference of the Canadian Society for Civil Engineering 2007: Where the Road Ends, Ingenuity Begins
Citation
Alkaabi, S. (Salem), van Geel, P, & Warith, M.A. (Mostafa A.). (2007). Mathematical modelling of MSW biodegradation in bioreactor landfills operating under saline environment. Presented at the Annual Conference of the Canadian Society for Civil Engineering 2007: Where the Road Ends, Ingenuity Begins.