Substrate selection The food refuses and vegetable peelings from the food mess, public cafe and boarding house mess of Adithya Institute of Technology, Tamil Nadu were collected and used. The composition of the collected wastes included boiled rice (30%), wheat (20%), vegetable peelings and vegetable wastes (35%) and other vegetarian ingredient such as grams, grains, etc. (15%). Cow dung from the nearest farm was also collected and mixed with the food wastes at various compositions in a set of 42 five-liter digesters. The digester was secured from foreign materials such as sand, sawdust, gravel, etc., by sealing it. The produced biogas was collected through an L-type glass tube insert into the cork which was then sent for measurement by water displacement method through a rubber tube.
Experimental procedure …show more content…
For characterization of the different kitchen waste, 42 five-liter digesters were built and were separated with two sets each set having 21 digesters respectively. Each digester was filled with a total of 2 kg of raw materials which is a mixture of food waste and cow dung at different composition as per Table 1. The second set of digesters is used for verification in the purposes of same raw material simultaneously to check the strength of results. The digesters were moved manually by the method of shaking without opening the cap to prevent the escape of gas. A pH tape was used to measure the pH value before the raw material was added into the digester after the digestion period. The readings were taken from the 5th day of digestion up to 45th day which range from 6 to 8.