Study on biogas generation from organic kitchen waste and domestic sewage

Abstract

The present study was aimed to investigate the anaerobic digestion process of a mixing of organic kitchen wastes (cooked & uncooked) obtained from Sreepur Shishu Palli and cowdung. Mixing of slurry is the basic requirement for better performance of biogas generation. Attempts were made to investigate the effect of mixing on biogas generation process and to study the feasibility of biogas generation from human excreta. The experimental results reveal that mixing significantly increases the biogas generation. 24 hour's interval was found as optimum interval for mixing in this experiment. Gas generation pattern from different mixing ratio of waste material and cowdung reveals th'3t mixing of waste material with cowdung more or less give the same amount of gas as from 100% cowdung. The feed raw materials cowdung and cooked waste are partly digested. So in the digestion process of cowdung and cooked waste, effective fermentation time may be considered 60 & 80 days respectively. Experimental result also revealed that use of uncooked waste as raw material, pre-digestion or hydrolysis is required for efficient use of the biogas digester. A duration of 30 days appears to be the most suitable pre-digestion period for the material of uncooked waste. Then an attempt was also been made to assess the potential for the implementation of biogas technology in Bangladesh. Assessment of potential for biogas technology in Bangladesh indicates that the best possible utilization of organic wastes ( cowdung, sheep, goat and poultry dropping, human excreta, solid wastes) through biogas generation can meet up 15% fuel wood demand of Bangladesh. Therefore the application of this technology in rural and semi urban area of Bangladesh will provide an excellent renewable source of energy and nutrient and will also improve human health and environment.