Effect of Inoculum Concentration on Co-digestion of Kitchen Waste and Cattle Dung

Anaerobic co-digestion of kitchen waste and cattle dung mixed in the ratio of 1: 1 with different concentrations of inoculums viz. 10%, 15%, 20% and 25%, respectively, was carried out in 10 l capacity lab scale batch reactors. Maximum average biogas yield (10.05 l.kg^-1 TS fed) was observed in reactor operated with 25% inoculum followed by reactor with 20% (9.77 l.kg^-1 TS fed), reactor with 15% (9.35 l.kg^-1 TS fed) and reactor with 10% (9.27 l.kg^-1 TS fed) inoculums. Maximum increase in N (18.49%), P (17.64%) and K (19.41%) was also observed in digested slurry of the reactor operated with 25% inoculum. The degradation of total solids (27.74%) as well as volatile solids (25.71%) was highest in the same reactor.