ANAEROBIC-DIGESTION OF FRUIT AND VEGETABLE PROCESSING WASTES FOR BIOGAS PRODUCTION

The effect of feeding different fruit and vegetable wastes, mango, pineapple, tomato, jackfruit, banana and orange, was studied in a 60-liter digester by cycling each waste every fifth day in order to operate the digester as and when there was supply of feed. The characteristics of the anaerobically digested fluid and digester performance in terms of biogas production were determined at different loading rates (LR) and at different hydraulic retention times (HRT), and the maximum biogas yield of 0.6 m3/kg VS added was achieved at a 20-day HRT and 40 kg TS m-3 day-1 loading rate. The hourly gas production was observed in the digesters operated at 16 and 24 days HRT. The major yield (74.5%) of gas was produced within 12 h of feeding at a 16-day HRT whereas at a 24-day HRT only 59.03% of the total gas could be obtained at this time.