(184i) Modeling Anaerobic Digestion of Biodegradable Solid Waste

Authors: 
Skillings, D., South Dakota School of Mines and Technology
Anaerobic digestion (AD) is the biological conversion organic matter into methane gas. The

US Air Force aims to use this process to treat the biodegradable solid waste produced on their forward

operating bases (FOBs). The focus of this study was to obtain the Monod kinetic parameters of AD

process intermediates (volatile fatty acids, monomers, and polymers) that are typical of waste produced

on FOBs. To obtain Monod kinetic parameters a combination of experimental and computational

methodologies were applied. First, the AD of a single concentration of each of the substrate was

regressed to obtain preliminary saturation constants (K s ) and maximum rates (µ max ) and next, these

preliminary values were used to obtain actual experimental values. The experimental values obtained

for the volatile fatty acids include: K s = 0.28 g L -1 , µ max = 0.00080 g COD g VSS -1 h -1 for acetic acid, K s = 0.22

g L -1 , µ max = 0.00049 g COD g VSS -1 h -1 for butyric acid, and K s = 0.089 g L -1 , µ max = 0.00031 g COD g VSS -1 h -1

for propionic acid. The parameter values obtained were within the range of previously reported

literature values. Once all of the kinetic parameters are obtained, the parameters will be incorporated

into the Anaerobic Digestion Model No.1 (ADM-1). ADM-1 predictions will be compared to batch AD

performance for food waste, and model deficiencies will be discussed.