Enhancing Biogas Production from Pumpkin (Telfairia occidentalis) Stalk Waste through Its Blending with Cow Dung and Alkaline Sodium Hydroxide Pretreatment

Abstract

Improvement of biogas production from Pumpkin (Telfairia occidentalis) stalk waste through its blending with cow dung and alkaline sodium hydroxide pretreatment was investigated. Untreated pumpkin stalk waste (Un-PST) acted as the control. Initial verification carried out using this waste led to the present investigation. The batch digestion process anaerobically took place for 30 days under ambient atmospheric conditions. Bio-digesters of 41.00 dm3 working volume were utilized. Cumulative volume of biogas yield from the cow dung blended with pumpkin stalk (PST-cd) was 3.57 dm3/TS.kg and alkaline treated waste (PST-t) gave 4.48 dm3/TS.kg, while untreated pumpkin stalk waste (Un-PST), yielded 1.50 dm3/TS.kg. Each of these systems also produced flammable gas at different times: the Un-PST -15th day, PST-cd -5th day and PST-t-8th day, respectively. Paired sample T-Test carried out on volume of gas data indicated that t (t statistic) was 5.15 for paired sample Un-PST & PST-cd while 6.51 for Un-PST & PST-t with degree of freedom as 29; at 95% conf. interval. Hence, there was a significant (p<0.05) difference in volume of gas production between the untreated and treated waste systems. Overall, results indicate that the yield of biogas from the waste through the different treatments were significantly (p<0.05) enhanced for renewable energy production, sustainable environment and wealth recovery for urban and rural dwellers of developing countries such as Nigeria, when properly harnessed.