Biogas Generation from Sorted Domestic Organic Waste in Sokoto Metropolis: Yield, Composition, and Digestate Fertilizer Quality

This study investigates biogas production from sorted domestic organic waste in Sokoto, Nigeria, demonstrating promising methane yields and improved digestate nutrient content while highlighting the need for pathogen-reduction treatment before agricultural application.

Lubabatu Muazu Jodi

10/10/20261 min read

ABSTRACT

The escalating challenges of municipal solid waste management and energy poverty in Nigeria necessitate the exploration of sustainable waste-to-energy solutions. This study investigated the biogas generation potential, gas composition, and digestate fertilizer quality from sorted domestic organic waste collected from households in Sokoto Metropolis, Sokoto State, Nigeria. Domestic organic waste comprising food scraps, fruit peels, and vegetable residues was characterized for physicochemical properties, including moisture content (71.8 ± 2.9%), volatile solids (85.2 ± 3.1% on a dry basis), and carbon-to-nitrogen (C/N) ratio (15.8:1). Batch anaerobic digestion was conducted under mesophilic conditions (35 ± 2°C) for 40 days using rumen content as inoculum. Cumulative biogas production reached 472.3 mL per gram of volatile solids, with a methane content of 63.1 ± 2.8%. The digestate exhibited enhanced fertilizer quality, with nitrogen content increasing by 11.1%, phosphorus by 12.5%, and potassium by 16.7% compared to the feedstock. Microbial analysis of the digestate. revealed the presence of Bacillus and Pseudomonas species, whose taxonomic presence does not by itself confirm a nitrogen-fixing or plant-growth-promoting function; potential pathogenic indicator organisms (Salmonella enterica and Clostridium perfringens) were also detected, indicating that further pathogen-reduction treatment is required before agricultural use. The findings demonstrate that sorted domestic organic waste from Sokoto Metropolis represents a viable feedstock for biogas production, with the digestate offering substantial potential as a bio-fertilizer for agricultural applications in Sokoto State. This study provides preliminary, laboratory-scale evidence in support of small-scale anaerobic digestion as a household waste management and renewable energy option for urban Nigerian communities; pilot- and field-scale studies are needed before wider adoption is recommended.

Keywords: Biogas, domestic organic waste, anaerobic digestion, methane yield, digestate fertilizer, Sokoto, Nigeria

HOW TO CITE

Lubabatu, M. J. (2026). Biogas Generation from Sorted Domestic Organic Waste in Sokoto Metropolis: Yield, Composition, and Digestate Fertilizer Quality. Nexus Inventio: Journal of Science, Innovation and Education, 1(1), 42–52.

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