THE EFFECT OF SEWAGE CONCENTRATIONS AND MATERIALS OF CONSTRUCTION OF SEWAGE DIGESTER ON BIOGAS PRODUCTION
The effects of two sewage concentrations and bioreactor types on biogas generation capacity have been investigated. Different bioreactors including plastic, mild and galvanised steel were used. Results obtained show that more than 10 litres of biogas was generated from 0.4kg/l of 15 litres sewage as against 4.6 litres generated from equal volume of sewage of 0.5kg/l concentration. This indicated that an optimum sewage concentration exists, which favours biogas production. Also, while the metallic bioreactors such as mild and galvanised steel as used in this study inhibited biogas production, the transparent plastic bioreactors enhanced its production. Furthermore, it was noticed that increasing ambient temperatures from 28 to 31oC increased the biogas output from the two sewage concentrations.Â Â Â
Keyword: Biogas, sewage, concentration, plastic and metallic bioreactors.