Full Length Research Paper

Comparison of biogas productivity of cassava peels mixed in selected ratios with major livestock waste types

B. A. Adelekan¹ and A. I. Bamgboye²

¹Department of Agricultural Engineering, College of Engineering and Technology, Olabisi Onabanjo University, PMB 5026, Ibogun, Ogun State, Nigeria.

²Department of Agricultural and Environmental Engineering, Faculty of Technology, University of Ibadan, Ibadan, Nigeria.

*Corresponding author. E-mail: jideadelekan@yahoo.com .

Accepted 23 June, 2009

   Abstract

Biogas productivity of cassava peels, mixed with poultry, piggery and cattle waste types in ratios 1:1, 2:1, 3:1 and 4:1 by mass, was investigated using 12 Nos. 220l batch type anaerobic digesters in a 3 x 4 factorial experiment using a retention period of 30 days and within the mesophilic temperature range. Biogas yield was significantly (P ≤ 0.05) influenced by the different mixing ratios of livestock waste with cassava peels. The cumulative average biogas yield from digested cassava peels was 0.6 l/kg-TS. The average cumulative biogas yield increased to 13.7, 12.3, 10.4 and 9.0 l/kg-TS respectively for 1:1, 2:1, 3:1 and 4:1 mixing ratios when cassava peel was mixed with poultry waste. On mixing with piggery waste, the average cumulative biogas yield increased to 35.0, 26.5, 17.1 and 9.3 l/kg-TS respectively for 1:1, 2:1, 3:1 and 4:1 mixing ratios.  In the case of mixing with cattle waste, the average cumulative biogas yield increased to 21.3, 19.5, 15.8 and 11.2 l/kg-TS respectively for 1:1, 2:1, 3:1 and 4:1 mixing ratios. Results show that for all livestock waste types, mixing with peels in the ratio 1:1 by mass produced the highest biogas volumes, and highest in piggery waste.

Key words: Anaerobic digestion, biogas, cassava peels, cattle waste, poultry waste, piggery waste.

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