Physicochemical and Biochemical Characterisation of Ackee Apple Pod as a Potential Feedstock for Anaerobic Digestion
1*Olojede, M. A., 1Okekunle, P. O., 2Aworanti, O. A.
1Department of Mechanical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
2Department of Chemical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
DOI: 10.36108/laujoces/6202.71.0122
Abstract
The growing global demand for energy for domestic and industrial applications has intensified reliance on fossil fuels, resulting in increased anthropogenic emissions, environmental degradation, global warming, and pollution. This study evaluated the potential of ackee apple pod as a substrate for biogas production through physiochemical and biochemical characterisation. Fresh ackee apple pods were collected from Odo-Oba Village, Ogo-Oluwa Local Government Area, Ogbomoso, Nigeria, mechanically processed into powder, and characterised using standard analytical techniques. Dry Matter (DM), Organic Dry Matter (ODM), Organic Carbon (OC), and Organic Nitrogen (ON) were determined following APHA standard methods, while morphological structure, elemental composition, functional groups, and microbial characteristics were analysed using Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM/EDX), Fourier Transform Infrared Spectroscopy (FTIR), and Bergey’s Manual of Determinative Bacteriology. The results showed DM and ODM values of 94% and 86%, respectively, with OC, ON, C/N ratio, and gross calorific value of 16.85%, 0.35%, 24:1, and 19.3 MJ kg⁻¹ respectively. SEM analysis revealed a rough, highly porous surface with a particle size of 2.69 mm, height of 1.98 mm, and bulk density of 2.15 g cm⁻³, while EDX identified essential elements including Silicon Si (24.07%), Aluminum Al (6.70%), Calcium Ca (5.70%), and Magnesium Mg (2.82%). FTIR confirmed the presence of cellulose, hemicellulose, and lignin, and the predominant anaerobic bacteria were Bacillus polymyxa and Escherichia coli. These physicochemical, structural, and microbial characteristics indicate that ackee apple pod is a promising lignocellulosic feedstock for efficient biogas production through anaerobic digestion.
Keywords: Ackee apple pod, Dry Matter, Organic Dry Matter, Bacillus Polymyxa, Escherichia coli, Carbon-Nitrogen ratio