TITLE:
The Effects of Microwave Pretreatment of Dairy Manure on Methane Production
AUTHORS:
Ian Chan, Asha Srinivasan, Ping H. Liao, Kwang V. Lo, Donald S. Mavinic, Jim Atwater, James R. Thompson
KEYWORDS:
Liquid-Solids Separation; Microwave Treatment; Anaerobic Digestion; Methane Production
JOURNAL NAME:
Natural Resources,
Vol.4 No.3,
July
1,
2013
ABSTRACT: This study was undertaken to evaluate the efficiency of a liquid-solids separation process and microwave pretreatment, as well as anaerobic biodegradability of microwave pretreated dairy manure. Liquid-solids separation of raw dairy manure resulted in solid and liquid fractions having different properties, with the solid fractions richer in total and volatile solids content and liquid fractions richer in nutrients and metal ions. Substantial amounts of soluble chemical oxygen demand and nutrients were released into the solution after the microwave treatment. The microwave pretreated dairy manure was also subjected to anaerobic digestion. The kinetic parameters of methane production potential, maximum methane production rate and lag time were determined using the modified Gompertz equation. Anaerobic digestion of liquid manure, without microwave treatment, outperformed the sets with microwave treatment. The microwave-treated liquid dairy manure, without acid addition had better results in terms of methane potential and methane production, than with acid addition. Thermophilic digestion exhibited a higher maximum methane production rate than that of mesophilic digestion, but lower methane yields. The microwave pretreatment of dairy manure resulted in high soluble chemical oxygen demand; however, methane yield was not increased.