Abstract
This study examines appropriate transportation distances for the proper disposal and recycling of industrial wastes. We conducted the analysis by combining the results of a questionnaire survey with information held by local governments. Specifically, we calculated the capacity of waste treatment facilities in Kitakyushu City and the percentages of wastes that could be changed based on the reasons for choosing the disposal sites. Then, we determined the amount of waste to be transported and treated outside of Kitakyushu City by optimization calculation. Furthermore, we quantitatively evaluated the results in terms of carbon dioxide emissions. The results showed that treatment facilities in the city have enough surplus capacity, except for the facility for ash. As for the possibility of changing destinations, some wastes, including oil, acid and alkali, are difficult to treat. On the other hand, the destinations of some wastes, including animal and vegetable residues, mineral waste and wood, could be easily changed. In addition, we solved the transportation problem to minimize the transportation ton-km and obtained a maximum effect of reducing carbon dioxide emissions by 51% from the current level, quantitatively showing the effect of measures to shorten transportation distances.
