ANAEROBIC DIGESTION OF LOW- AND HIGH-SOLIDS FOOD WASTE UNDER MESOPHILIC CONDITIONS

In developing countries, food waste accounts for a significant fraction of municipal solid waste stream, the proper disposal of which poses a major challenge. This paper examined the biogasification of food waste in an anaerobic process for methane production, which is a proven technology for the treatment of organic waste streams. The food waste stream considered here included low- and high-solids with and without inoculation with sewage sludge. The process was carried out in a lab-scale batch reactor equipped with a control unit under mesophilic conditions. In addition to methane production, kinetics of the process was also analyzed. It was found that the food waste biodegradation followed a first order model as evidenced by an R2 of 0.96 compared to 0.77 and 0.67 for the zeroth- and second-order models, respectively. The findings also indicated that samples of higher solids content enjoyed a shorter lag time while inoculation with sewage sludge resulted in a much shorter lag time and a significantly higher specific biogas production of up to 10 to 13 times as compared to the experiments without inoculation.