UBC Theses and Dissertations
The characterization of the aerobic-thermophilic degradation of potato wastes Yee, Sherman Jack
Feasibility of the biodegradation of neutralized-caustic potato peel waste by aerobic-thermophilic fermentation was examined. Fermentation temperature, pH, rate of solids utilization, dissolved oxygen and total organic nitrogen were characterized with respect to the fermentation process. Examination of these parameters showed distinct characteristic behaviour, though the parameter magnitude varied between the trials. The naturally occurring flora of thermophilic microorganisms of the potato was sufficient as an inoculum, with their propagation creating the fermentation characteristics. The solids content of the potato waste was reduced by the thermophilic fermentation with a noticeable improvement in the nitrogen content in the remaining residue. Protein and amino acid analyses supported the feasibility of using the remaining residue as animal feed. Increases in the nitrogen content of the substrate was assumed to be due to the conversion of atmospheric nitrogen by nitrogen-fixing microorganisms within the fermentation. Microbial identification indicated that these organisms belonged to the species Bacillus coagulans. No strains within this species have been previously reported to fix atmospheric nitrogen. It was concluded that an aerobic-thermophilic fermentation can be utilized as a waste treatment process for caustic potato peel waste. Besides the numerous advantages of an aerobic-thermophilic fermentation, the validity for the utilization of this fermentation process in the treatment of potato peel waste is the near total disposal of the waste.
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