Balakrishna, GowdaPRIYANKA, PRASAD2017-08-282017-08-282015-12-23Th-11296http://krishikosh.egranth.ac.in/handle/1/5810029787Biogas is generated from the anaerobic digestion of organic wastes and is rapidly emerging means for providing continuous power generation. India produces a host of non-edible oils, which are essentially underutilized and can be used for bio-diesel. The seed cake after oil extraction can serve as a good feedstock for the generation of biogas. This study presents summary of results obtained in the anaerobic digestion of neem and pongamia oil cakes with different proportions of cow dung. The study revealed that pH of cow dung slurry in the beginning was 7.8, neem cake slurry 5.0 and pongamia cake 5.8, suggesting significant differences in pH among the bio-gas substrates used. Two months after anaerobic digestion, there was an increase in pH with increase in proportion of cow dung. However, there were no changes in EC in experiment. There was an increase in total-N and P in biogas spent slurry after anaerobic digestion. There was no definite trend with reference to total-K. There was decrease in organic matter content at the end of experiment in biogas slurry. The volatile solids also decreased in biogas substrates from the start of experiment to the end of anaerobic digestion. There was decrease in C: N at the end of the experiment. Significantly, very low C/N ratio was recorded in treatments 4:1 cowdung: neem cake and 1:1 cowdung: pongamia cake (3.24) at the end of 60 days. There was decrease in COD and volatile fatty acids at the end. The cumulative biogas for nine weeks was significant only cow dung (T1) (15755 cc) followed by 4:1 cow dung: neem cake (T7). This suggests, that oil cakes can serve as good feed stocks for biogas production.ennullThesis