Abstract
Co-digestion of sewage sludge and regional organic waste, such as kitchen garbage, is a promising energy recovery method for small facilities located in remote, and small and medium sized municipalities. Dewatering sewage sludge makes it easier to transport the sludge to a centralized wastewater treatment plant. The effects of sewage sludge characteristics on mesophilic anaerobic digestion performance and digested sludge qualities were investigated by continuous and batch experiments using sewage sludge from seven wastewater treatment plants. Biogas production of sewage sludge from conventional activated sludge processes was 0.4-0.5 NL/gVS, and that from oxidation ditch processes was 0.1-0.2 NL/gVS. This study proposes a simple estimation method for the ammonia concentration and viscosity of digested sludge. The 16S rRNA gene analysis showed different microbial communities under different substrate conditions.
