Optimization of Dry Anaerobic Digestion of Food Waste in Leachate Bed Reactors

This study investigates the optimization and performance of a single-stage leachate bed reactor (LBR) system for the dry anaerobic digestion (AD) of food waste (FW). Three different parameters were assessed in the LBR run at a reaction time of 10 days: the inoculum-to-substrate ratio (ISR), leachate recirculation rate, and type of inoculum. For ISR optimization, four different ISRs were investigated ranging between 10 and 60%. Results indicated that a higher ISR of 60% with an acclimated inoculum led to a 3.35-fold increase in cumulative methane yield compared to an ISR of 10%, while volatile solids (VS) reduction with an ISR of 10% was better than that with an ISR of 60%. Furthermore, increasing leachate recirculation rates improved methane yield, with a notable 78% increase observed when the recirculation rate was elevated from 0.3 to 7.5 L/h. These results demonstrate high methane production of 349 mLCH4/gVSreduced within a short digestion time of 10 days.