Effects Of Co-Digestion Of Poultry Droppings And Maize Cobs On Biogas Yields And Some Proximate Properties Of Their By-Products

Purpose: The study focused on Co-digestion trials of poultry droppings and maize cobs in order to assess its effects on biogas yield and some proximate properties of their by-products.Methodology: Five different treatment ratios A(25:75), B(50:50), C(75:25), D(100:0) and E(0:100) of these wastes in triplicates were made into slurries (1:3w/v ratio) and separately fed to 13.6L locally fabricated digesters for 56 days retention time. There was a progressive increase in biogas yield across the treatments within the first six weeks of digestion, followed by a sharp decline at the 7th and 8th weeks.Findings: All co-substrates treatments had higher gas yields in the order of B(2481.30ml) > D(2197.90ml) > A(2163.00ml) > C(2116.30) > E(1713.20ml). The proximate contents gave E(763.60%), A(153.73%), B132.44%), C(79.37%), D(48.06%) as % increases in ash, while %decreases in crude lipid and moisture contents were E (77.04, 21.02), B(72.70, 56.90), D(65.99, 40.94), A(65.70, 53.21) and C (56.83, 49.89), respectively. All but treatment D(5.74%) had % increases in crude protein. There was a general decrease in total solids(TS), volatile solids (VS), chemical oxygen demands (COD), metabolizable energy(ME). All co-substrates had higher % bioconversion efficiencies(%BE) over the singles with B(24.50%), C(57.90%) and A(21.39%) highest values for TS, VS and ME reduction, respectively. The % C/N reduction was in the order of treatment E(81.80%)> A(68.02%)> B(54.42%),>C(54.23%) >D (12.94%).Unique contribution to theory, practice and policy: The process had revealed the alternative energy potentials and consequential implication on the biochemical composition of the effluents