2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference

Effect of Substrate Composition on Anaerobic Digestion under Mesophilic Conditions

Dr. Laura Cordova Villegas, University of Windsor
Dr. Rajan Ray, University of Windsor
Dr. Rajesh Seth, University of Windsor (Presenter)
Dr. Nihar Biswas, University of Windsor

Energy supply and environmental protection are two crucial issues for the sustainable development of global prosperity. Anaerobic digestion is a well-known process to produce biogas from different municipal wastes and can be a solution for energy shortage. Wastewater can vary in composition, but the main types of compounds present are carbohydrates, proteins and lipids. A laboratory scale study using semi-continuous batch reactors with multiply cycles was done to understand the effects of different substrates: starch (model compound for carbohydrate), bovine serum albumin (model compound for protein) and acetic acid (model compound for lipids) and a mixture of all of them on the composition on biogas yield.  Experiments were also carried out to determine the changes in acclimatization of methanogens for the targeted substrate using sludge from municipal wastewater treatment plant digester. For a fixed 0.5 g COD/ g VSS feed, bovine serum albumin showed a maximum 250 Nml gas production within 7 days of HRT. Mix, acetic acid and starch followed by 8.5, 9 and 10 days after 3 cycles, respectively.  However, after the acclimatization of methanogens, the time to produce the maximum yield reduced to 5, 6, 6.5 and 7.5 days for protein, mix, acetic acid and starch after 6 cycles, respectively. The difference of rate for maximum gas productions was as follows: protein?mix>lipids?carbohydrates. Also, it was determined that the mix was the combined effect of each substrate; where each substrate contributes in the same proportion to the gas production.