Biogas Production from Blends of Cassava Waste Water and Cow Dung under Changing Meteorological Parameters
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Biogas production from cassava waste water (CWW) blended with cow dung (CD) in different proportions was studied in five treatments under changing meteorological conditions. The treatment cases A—100% CWW; B: 100% CD; C: 90% CWW + 10% CD; D: 70% CWW + 30% CD; and E: 50% CWW + 50% CD— were digested under anaerobic conditions in model batch, metallic biodigesters of 32.0 litres for 30 days within ambient conditions. The digester performances indicated that 100% CD system flamed on the 6th day, 70% CWW + 30% CD system flamed on the 16th day, 50% CWW + 50% CD system flamed on the 17th day while 100% CWW system and 90% CWW + 10% CD systems didn’t flame at all. The cumulative gas yield from the five treatments was different: the 100% CWW had cumulative gas yield of 12.7 litres/24 kg mass of slurry; 100% CD had cumulative gas yield of 41.5 litres/24 kg mass of slurry; 90% CWW +10% CD had cumulative gas yield of 13.85 litres/24 kg mass of slurry; 70% CWW+30% CD had cumulative gas yield of 14.85 litres/24 kg mass of slurry while 50% CWW + 50% CD had cumulative gas yield of 7.55 litres/24 kg mass of slurry during the 30 days retention period. 100% CD had 79.9995% methane; 70% CWW + 30% CD produced 79.9995% methane while 50% CWW + 50% CD produced 88.499% methane. Daily biogas yields were also modelled as functions of meteorological parameters and results recorded