TITLE:
Evaluation of Biogas Production from Wastewater Treatment Plants in Owerri Municipality
AUTHORS:
Protus Nnamdi Okebaram, Luke Okwuchukwu Uzoigwe, Julius Ibeawuchi Onyewudiala, Gerald Ibe Okwe
KEYWORDS:
Anaerobic Digestion, BioWin Simulation, Biogas Production, Matlab Software
JOURNAL NAME:
Open Access Library Journal,
Vol.13 No.10,
October
9,
2026
ABSTRACT: The unabated energy crisis, growing volume of wastewater and poor waste management system have been an issue of utmost concern. In this research, biogas production potentials from wastewater sludge of the two wastewater treatment plants (WWTPs) plants A (Aladinma) and B (Ikenegbu) of Owerri Municipality were examined, evaluated and the socio-economic benefits were evaluated by using BioWin and MATLAB softwares. The chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), and volatile suspended solids (VSS) were used for the characterization of wastewater sludge samples. The measured parameters were used in BioWin for modelling anaerobic digestion for different operating conditions such as temperature, retention time, organic loading rate (OLR) and influent COD concentration. Then, MATLAB software was used for numerical calculation, graphical representation, sensitivity analysis, comparison analysis and energy-economic-environmental calculation benefits. The BioWin simulation predicted a biogas production of 700 m3/day from Aladinma and 850 m3/day from Ikenegbu, resulting in a total production of 1550 m3/day. Average concentration of methane was 60.5% and specific yield of methane was 0.16 - 0.19 m3 CH4/kg COD removed. Among the measured parameters, MATLAB sensitivity analysis revealed that the temperature and the influent COD concentration were the most significant parameters for methane production. Total electrical-energy recovery potential of the two plants was 1.14 GWh/year, which corresponds to roughly 39.5% of the total electrical energy demand. Electricity-cost savings were calculated at an electricity tariff of ₦120/kWh, and approximated at an annual electricity cost saving of roughly ₦136.7 million, with an estimated payback period of 3 - 5 years. The study also calculated a greenhouse-gas mitigation of about 574 tonnes CO2-equivalent per year. The findings confirmed that wastewater sludge is a good renewable-energy resource, and the integrated BioWin-MATLAB framework can be effectively used as a basis for the optimization of biogas production and assessment of the technical, economic and environmental potential of wastewater-to-energy systems in Nigeria.