Mineral Requirements for Mesophilic and Thermophilic Anaerobic Digestion of Kitchen Garbage

Abstract

Anaerobic digestion of Japanese standard kitchen garbage was conducted in conventional CSTRs under both mesophilic and thermophilic conditions. The lab-scale reactors were fed with kitchen garbage containing 10%-TS at a HRT of 30 days (3.0-3.5 g-TS 1-1 d-1 of volumetric loading rate). Both mesophilic and thermophilic reactors exhibited process failure due to severe acidification. A restoration of methane yield based on the VS of the garbage added was observed after the addition of minerals (Ni, Co, and Fe) in the mesophilic but not in the thermophilic, suggesting that the requirement for minerals is higher in thermophilic anaerobic digestion than in mesophilic digestion. Among those minerals, it is suggested that Ni is the most important for anaerobic digestion of japanese standard kitchen garbage.