Abstract
In many small cities, an oxidation ditch (OD) process is widely used in a wastewater treatment plants, and a large amount of dewatered OD sludge is generated. Meanwhile, a lot of organic wastes are being generated from food manufacturing processes. However, if co-digestion of dewatered OD sludge and organic wastes is conducted, it is possible to promote the digestion efficiency in a sludge treatment processes. Moreover, co-digestion under high-concentrated condition enables scaling down of the sludge treatment process. In this study, continuous co-digestion experiment using high concentration OD sludge and fried tofu was conducted under mesophilic condition. The digestion progressed stably when organic loading rate was 3.4kg-VS/m3/d (OD sludge) and 3.5kg-VS/m3/d (fried tofu mixture). By controlling the substrate organic loading rate, co-digestion using high concentration OD sludge and organic wastes is applicable for small scale facilities.
