PRODUCTION OF BIOGAS FROM CO-DIGESTION OF GOAT MANURE AND WATERMELON (CITRULLUS LANATUS) FRUIT PEELS

Abstract

Biogas is an alternative source of energy that is produced by methanogenic bacteria through the bio-degradation of organic material under anaerobic conditions. In this study, biogas production from co-digestion of the goat manure (GM) and watermelon peels(WMP) in five mix ratios were evaluated under 38ºC using batch fermentation. In all treatments, physico-chemical parameters such as total solid (TS) and volatile solid (VS), organic carbon, and pH were measure before and after digestion. The daily biogas production was subsequently measured by water displacement method for 27 days. All measured of physicochemical parameters of each substrate significantly varied (p<0.05) between before and after anaerobic digestion. Gas production was noticed in all of the digesters from the third day of digestion and went down to zero at about the 23rd days in all substrates. Assessment of cumulative biogas production revealed that the substrate mix ratio of 30% GM and 70% WMP showed the highest production, suggesting this mix ratio of the two substrates is an optimal mix to yield 242.0ml biogas. Overall the results indicated that the increment of biogas yield can be significantly enhanced when GM and WMP are co-digested.