Biogas Production from Community Waste to Optimise the Substrate for Anaerobic Digestion

Abstract

Worldwide, large quantities of waste are generated from human settlements. Anaerobic digestion (AD) of the produced community waste for biogas production is an apt solution for an efficient recycling and for a mitigation of the GHG (green house gas) emission for a clean environment. But, AD is affected by some factors namely, the composition of the substrate, the operational parameters and the type of digesters. The optimisation of the foresaid factors will enhance the performance of the anaerobic digesters and it will mitigate the release of noxious gases. Hence, current study efforts have been made, in order to study the biogas production from the anaerobic digestion of organic canteen leftover in different combinations of vegetable waste (VW), banana peel (BP), banana stalk (BS), food waste(FW) and spent tea waste (TW) for substrate optimisation. Tea waste has been used as a common input with all the combinations. Fabricated biogas digesters of one litre capacity have been designed and the daily recordings of gas production have been noted by the water displacement method. Statistical analysis has been done, by using IBM Statistics tool, in order to compare the actual and the predicted yield from the different combinations of the substrate. The [cow dung + (vegetable left over +tea waste)] with T3 =50%CD + [50% (VW +TW)] combination has yielded better result with a gas yield of 3.75 litres of biogas throughout the experimental period. Maximum gas production and methane yield has been observed for food waste followed by vegetables leftover. Variation in the pH of the digester has been the major limitation and a concrete research needs to be carried out to evolve strategies to stabilise the pH for optimised AD