KONDUSAMY DHAMODHARAN AND AJAY S. KALAMDHAD
Abstract
Food waste as a highly decomposable feedstock can be utilized for the production of methane gas. Mixture of food waste from the institute hostels and digester sludge were used as substrate and inoculum respectively. Experiments were conducted for different food to microorganisms (F/M) ratio on the basis of volatile solids (VS) in mesophilic conditions and it was found that F/M ratio maintained at 2 yielded higher VS reduction and high methane production. The nitrogen was added as 250, 500, 750 and 1000 mg L-1 in reactors of same food and inoculum concentrations with control. The VS destruction was higher as 68% after 30 d of biochemical methane potential test in 500 mg L-1 nitrogen added reactor and achieved a gas production of 410 mL methane g-1 VS degraded. Kinetic studies showed the higher P value of 3.8804 L CH4 and R2 value of > 0.98 for the higher methane production reactor. Higher nitrogen content decreased the gas production. The study concluded that the amount of methane produced depends on F/M ratio and nitrogen content in food waste. Anaerobic digestion of food waste needs high active methanogens and nitrogen content to increase the microbial growth because of its high VS percentage and volatile fatty acids production.