Abstract:
Biogas production at low temperature regimes is
annoyingly slow and yields low biogas volumes. Most biogas
supplements are expensive and substrate-specific. The effects of
two bio-catalysts Saccharomyeces spp. and Acanthaceae spp. and
an inorganic catalyst ferric oxide on biogas production using cow
dung slurry was investigated. 1.5L batch anaerobic digester
operating in unstirred cryo-mesophilic temperature regime of
20.0 -24.5 0C were utilized. The substrate underwent mild
synergistic pre-treatment by steaming with 1% sodium
hydroxide solution. The alkalinity and volatile acids of the
substrates were insignificantly perturbed by inclusion of the
additives. Additives Saccharomyeces spp. and Acanthaceae spp.
stabilized digestion temperature while ferric oxide stabilized pH
drifts. The overall biogas yields produced in the 100-day
retention period were in the order of 4615ml (990.34ml/g-Volatile
solids) for ferric oxide, 2335ml (494.08ml/g-Volatile solids) for
Saccharomyeces spp., 1750ml (328.94ml/g-Volatile solids) for
Acanthaceae spp. and 1030ml (212.37ml/g-Volatile solids) for the
control sample. Use of these additives would thus optimize biogas
production in cold countries.
