BIOGAS PRODUCTION POTENTIAL OF SELECT RAW MATERIALS COMMONLY FOUND IN HOUSE HOLD WASTE

Abstract

Most of the people in Sri Lanka do not have enough and distinct knowledge about biogas technology, suitable raw materials and biogas production potential of such raw materials. In this study, evaluate the composition, physical and chemical properties of house hold waste, and to determine the biogas production potential of selected raw materials. After evaluating the selected raw materials, biogas production potential was determined. News papers, papaya peels ,banana peels, coconut scraped refuses, potato refuses, rice, and mixture of those waste were fed into the batch  digesters (4.5 L) with inoculums and sealed to maintain anaerobic condition. Each treatment comprised 400 g of raw materials (dry weight).  C:N ratio of each treatment was adjusted before sealing the reactors. Daily biogas productions of every treatment were recorded and pH adjustment was done where necessary in all reactors. Gas production started in all the reactors 16 days after filling. Highest gas production (10473.1mL) was observed in reactors having mixtures of wastes during 41 days while lowest gas production (754mL) was recorded in reactors with coconut scrap refuses in 27 days. Average duration of gas production for most of the waste was 54 days. pH was reduced in the mixture of reactors at the beginning down to 3.91 and it was adjusted to improve the gas production. Papaya peel and coconut scrap were the highest and lowest degradability waste respectively. It appears that this technology is a good option for the management of the organic fraction of household waste.