Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Dr. George Nakhla


The aim of this study was to assess the synergistic effects of co-fermentation of glucose, starch, and cellulose using anaerobic digester sludge (ADS) on the biohydrogen (H2) production and the associated microbial communities. At initial pH of 5.5 and mesophilic temperature of 37 ºC, the H2 yields were greater by an average of 27 ± 4% in all the different co-substrate conditions compared to the mono-substrate conditions, which affirmed that co-fermentation of different substrates improved the hydrogen potential. The sensitivity of mesophilic ADS to a temperature shock was also investigated. Unacclimatized mesophilic ADS responded well to a temperature shock of 60ºC which was evident from lower lag phase durations. Interestingly, co-fermentation of starch and cellulose at mesophilic conditions enhanced the hydrogen yield by 26% with respect to mono-substrate, while under thermophilic conditions starch competed with cellulose as the carbon source for the microbial populations and no enhancement in the overall yield was observed.