Studies on biogas production from vegetable market wastes in a two-phase anaerobic reactor

The organic fraction of the municipal solid waste is not being properly utilized and is disposed in open dumps which leads to environmental pollution. The vegetable market wastes degrade rapidly than other municipal solid waste. In our earlier report, we concluded that single-stage anaerobic digestion systems could not be operated with higher loading rates for the digestion of vegetable market wastes (VMW). Hence, in this investigation, we proposed anaerobic digestion of VMW in a two-phase semi-continuous anaerobic reactor. In this study, the effect of organic loading rates (OLR) and hydraulic retention time (HRT) in methanogenic reactors was investigated. It was found that the specific biogas production increased with an OLR from 1.5 to 4.5 gVS/L/d and decreased with further increase in OLR. Maximum specific biogas production and methane yield of 0.721 ± 0.010 L/gVS_add and 0.469 L_CH4/gVS_add were obtained at OLR of 4.5 gVS/L/d and a 25-day HRT in methanogenic reactor. Kinetic parameters of maximum yield and specific growth rate were evaluated by Chen–Hashimoto model.