| This thesis evaluated the effectiveness of ultrasonic pretreatment on biochemical methane potential (BMP) of corn-ethanol by-products (dried distiller grain with solubles (DDGs), centrifuge-solids, thin stillage, and corn-syrup) and four types of animal manure (swine slurry, beef feedlot manure, dairy manure slurry, and solids separated dairy manure effluent) and energy efficiency of ultrasonic pretreatment. Ultrasonic pretreatment was applied with various amplitude and treatment time settings. Biogas production was measured and analyzed for methane content and methane yield. Ultrasonic pretreatment of DDGs, centrifuge-solids, swine slurry, beef feedlot manure, dairy manure slurry, and solids separated dairy manure effluent increased methane production by 25, 12, 14, 55, 37 and 8%, respectively. An increase in ultrasonic amplitude and treatment time resulted in an overall increase in methane production, but with a reduction of energy efficiency. The greatest energy efficiency was obtained with the lowest ultrasonic amplitude combined with the shortest treatment time used.;Keywords: Animal manure; Biochemcial methane potential assay (BMP); Corn-ethanol by-product; Methane yield; Ultrasonic. |
