Co-digestion of cow dung with organic kitchen waste to produce biogas using Pseudomonas aeruginosa

Abstract

The anaerobic digestion process for biogas production was investigated on food waste (FW) and cow dung (CD) using Pseudomonas aeruginosa as inoculum. The food waste and cow dung were co-digested as the substrate with bacteria (P. aeruginosa). Five digesters were prepared to observe the maximum gas production potential, methane production rate and duration for biogas production. Food waste (FW) was co-digested with bacteria in two proportions (1:5ml, 1:10ml) and co-digested with Cow dung (CD) in two proportions (1:1, 1:0.5). The digesters were all operated in batch process under mesophilic condition (35?C). The daily weights of the tubes were measure and some physical characteristics of the substrate were determined before and after the process. Production of gas started 3-4 days after commencement for the digesters with cow dung, 4-5days for the digesters with bacteria and 3 days with only food waste. Food waste with 1kg, cow dung produced the most biogas with a cumulative volume of 88.5g/kg. The highest concentration of biogas was found in the 1st digester consisting of 2kg CD and 2kg FW with a methane content of 52% and 48% CO2. The availability and renewable nature of food waste, ease of management of biogas produced and development of energy makes biogas a better option than the use of fossil fuel to the much-awaited solution to the energy crisis in Nigeria and developing countries.