Influence of Potash on Biogas Production from Cow Dung and Food Waste

This study investigated the production of biogas from food waste co-digested with potash and cow dung as inoculant. The aim of this study was to determine the amount of biogas generated from the waste substrate. Experimental research design was used and it was carried out at Uturu, Abia State, Nigeria. 4% to 12% concentrations of the substrate were mixed and fed into anaerobic digesters labeled B1 to B9 for 90days. Result of ultimate analysis showed oxygen (41.33%,14.06%), nitrogen (3.23%,1.48%), carbon (36.50%,29.67%) and PH value(6.25, 8.47) for food waste and cow dung respectively. The quantity of biogas generated in the different digesters (B1-B9) was 1341.2, 1668, 1784.5, 1945.2, 1941.7, 2159.2, 2328.1 and 2428.5m3/day respectively. Analysis of Covariance (ANCOVA) used to model the biogas production volume showed that there was significant contributions in predicting the volume of biogas produced with F (9,611) = 2684.28 and p-value <0.0001. The effect of potash on biogas production revealed that there was an increase in the quantity of gas generated by the substrates with increase in quantity of potash added. Digester B1 with the lowest quantity of potash, generated 1341.2m3/day of biogas while Digester B9 with the highest quantity of potash, generated 2428.5m3/day of biogas in 90days. The flame test showed that the biogas burned with a blue flame. The findings revealed that biogas can be generated from co-digestion of food waste, potash and cow dung. Thus, potash could have helped to boost the biogas production. More studies should be done on how local organic materials can be useful for the production of more biogas.