Batch anaerobic digestion of simulated Bangladeshi food waste: methane production at different inoculum-to-substrate ratios and kinetic analysis

This study investigates the anaerobic biodegradation characteristics of a simulated Bangladeshi food waste. Biochemical methane potential experiments carried out in 500 mL batch digesters showed the methane yields of cooked meat, cooked fish, boiled rice, vegetable and mixed food waste (MFW) to be 541, 402, 319, 274 and 484 ml CH4/gVS, respectively. The biodegradability of 87%, 83%, 75%, 76% and 82% were obtained for cooked meat, cooked fish, boiled rice, vegetable and MFW, respectively. At mesophilic temperature (35 degrees C), a maximum of 484.41 ml CH4/g VS was observed at an inoculum to substrate ratio (ISR) of 1 followed by 280, 166, 194 and 43 mL CH4/g VS at ISRs 10, 2, 0.1 and 0.05, respectively. The modified Gompertz model utilised for estimating the kinetic parameters of methane production revealed the maximum methane production rate as 16.02 ml CH4/g VS.d at an ISR of 1 with lag phase of 3.8 days.