Abstract
As urban metabolism facility, the role of municipal solid waste incinerator (MSWI), fecal sludge treatment plant (FSTP) and wastewater treatment plant (WWTP) are important. In this study, we clarified the present situation of MSWI and FSTP cooperation by co-incineration of municipal solid waste (MSW) and dewatered fecal sludge (DFS) and discussed the possibility and potential of further cooperation.
First, we conducted a questionnaire survey on MSWIs, which have already conducted the co-incineration. From this result, 1. Distance between MSWI and FSTP is within 20 km, 2. Co-incineration ratio of DFS is 14% or less of total input waste to MSWI and 3. Operation ratio is less than 86% of MSWIs capacity, were considered desirable for the cooperation. In addition, the influence of co-incineration on MSWI was considered to be less in terms of the introduction of the equipment for DFS supply to MSWI, composition of exhaust gas from MSWIs and the amount of incinerated ash etc.
Next, we calculated the maximum amount of DFS to be able to incinerate with MSW in MSWI. 431,000 t/year of the DFS equivalent to 39.3% of the total and annual generation amount of DFS could be additionally co-incinerated with MSW in Japan. It was possible to co-incinerate 174,000 t/year of the DFS equivalent to 15.8% of the total and annual generation amount of the DFS with high feasibility. Finally, we also clarified the area which comparatively has many middle-size MSWIs is suitable to introduce co-incineration.
