Assessment of small scale biogas digesters in rural households in Sub-Saharan Africa

Abstract

The wastes generated from animal husbandry and the potential health hazards it carries to both the users and the underground water contamination is not well reported in Africa. Thus, digester design using brick was considered and found to be less cost-effective and portable with respect to Nigeria’s geological conditions and availability of materials. In this study, chicken droppings were collected from the Research farm of ATB University, Bauchi, was anaerobically digested for 6 weeks’ retention time using a small scale brick digester constructed at the FMEnv/ZERI Research Centre Following anaerobic digestion of chicken droppings in Nigeria, the raw slurries with a very high mean bacterial, Coliform, Escherichia and Yeast estimated above 10,000 CFU/ml reduced drastically to only 80 CFU/ml, 59 CFU/ml 43 CFU/ml and 90 CFU/ml respectively. The volume of methane gas produced was 0.0075 m³ daily for every 8 h and this burnt continuously for three hours’ test run daily for six days. The findings showed that the brick type digester was efficient in disinfecting contaminated chicken droppings while providing biogas and sterile mineralized fertilizer.