EVALUATION OF BIOGAS PRODUCTION FROM MIXTURE OF FRUIT AND VEGETABLE WASTES

Abstract

This study evaluated the biogas production potential of a mixture of fruit and vegetable wastes through anaerobic digestion over a five-week retention period.  Fruit and vegetable wastes were collected from Sheikh Gummi Area, Sokoto and were air-dried and ground into powder. A slurry was prepared by mixing the 100 g of combined wastes with 500 mL of water to give a a 1:5 ratio. Anaerobic digestion was performed using three (3) empty tins of 400 g capacity as a digesters via the water displacement method. Temperature and biogas yield were monitored daily, while pH was recorded before and after digestion. Bacteriological analysis followed APHA guidelines. Data were statistically analyzed using one-way ANOVA and paired sample T-tests at P<0.05. Results showed that week 4 had the highest biogas yield (765.00 ± 39.69 mL) and the least was (130.00 ± 52.92 mL) in week 5 . The pH decreased from (6.60 ± 0.36) before digestion to 5.40 ± 0.44 after digestion. Bacterial analysis revealed Bacillus subtilis as the most frequent isolate (54.54%), followed by Salmonella sp. (27.27%), and Escherichia coli (18.18%). The results demonstrate that a mixture of fruit and vegetable wastes is a promising substrate for biogas production. Further studies are recommended to explore co-digestion with animal waste and microbial optimization for enhanced biogas quality and volume.