Volumetric scale-up of a three stage fermentation system for food waste treatment

In this study, a volumetric scale-up of this system was designed and built on a field pilot-scale (total digester volume 10 m3), with the results from the field pilot-scale experiments compared with those from the bench-scale (total digester volume 0.4 m3) process prior to scale-up. The reduction rate of total chemical oxygen demand (tCOD) and the maximum methane content produced in the biogas from the bench-scale system were 90.6% and 72%; whereas those from the field pilot-scale system were 90.1% and 68%, respectively. The estimated methane yields were 282 and 254 l CH4/kg tCODdegraded in bench and field pilot-scale fermentation systems, respectively. These results indicate that the three stage fermentation system developed in this study can be applied as a commercial process for the disposal of food waste in view of process stability.