FUTURE RENEWAL PLANNING OF SEWAGE SLUDGE TREATMENT FACILITY IN RESPONSE TO CHANGE IN WASTE GENERATION

In this research, we developed future renewal scenarios of sewage sludge incineration facilities in Wakayama City considering changes in population and sewage sludge generation in 2010-2040. We also evaluated the reduction effects in energy consumption and greenhouse gas (GHG) emissions when promoting centralized treatment of sewage sludge and introducing low-carbon technologies into the incineration process. From the analysis, we reached the following conclusions: 1) The centralized treatment of sewage sludge improves capacity utilization rate of facilities, and then brings the enhancement of scale effects in energy saving and GHG reduction. 2) To discontinue operation of incinerators with low efficiency of energy as soon as possible enhances the reduction effects of centralized treatment. 3) To make a transition to centralized treatment and introduce a low-carbon technology can reduce GHG by 19.2%, compared with usual incineration and renewal.