Production of Methane from Municipal Solid Waste (MSW)

Anaerobic digestion is a promising technique to dispose of organic waste which depends on various parameters such as concentration of slurry, pH, volatile solids (VS), moisture content, total solids (TS), temperature, retention time, Carbon to Nitrogen (C/N) ratio and organic loading rate (OLR) are among the main parameters affecting biogas production. This study investigated the possibilities of improving methane yield from anaerobic digestion of municipal solid waste (MSW) including cow dung, fruit waste and vegetable waste by maintaining a constant organic loading rate weekly at different C/N ratios. C/N ratios of 10:1, 15:1, 20:1 and 25:1 were fed in 19 liters anaerobic with an effective volume of 15 liters operated in semi-continuous at mesophilic temperature.  Cow dung was employed as a seed for start-up in order to increase the digestion process. OLR were set at 1, 2, 3 and 4 g Volatile Solids per liter per day for 1^st, 2^nd, 3^rd and 4^th week respectively. The cumulative methane production for each of the substrates was measured over a 4 week period and it was observed that most gas was produced by C/N ratio of 20:1 and the rate of methane production was increased by increasing C/N value. The volume of biogas produced by the substrates was measured by water displacement technique. The results suggested that better performance of anaerobic co-digestion can be fulfilled by optimizing feeding composition, OLR and the C/N ratio.