Smart bins can increase transparency and accuracy in monitoring waste characteristics such as weight, volume, and disposal times. This information can aid in enforcing waste reduction policies, including the pay-as-you-throw (PAYT) system. However, the public's response to this technology remains uncertain. Despite Japan's reputation for high waste separation compliance and collection rates, it has one of the world's highest per capita rates of plastic and packaging waste generation. This study surveyed 1000 Japanese individuals regarding their perception of smart bin features and their potential to encourage waste reductions. Multiple correspondence analysis (MCA) was used to explore the relationships between respondents' social attributes and their responses. The findings indicate a slightly higher responses from younger respondents (above 85 % of those age 10-29 compared to around 75 % of those aged 60 and older) who were in favour of smart bin technology functions such as unscheduled waste pick up and automatized waste separation. On the other hand, there was a strong unwillingness (0.57 count ratio) to reduce plastic waste even if a smart bin assisted PAYT is introduced from those who did not engage in waste separation and cleaning in the first place. Finally, an open-ended question about strategies to reduce plastic waste resulted in a large portion of mindset change ideas (24.8 % of the female respondents) and technology innovations proposals (24 % of male respondents). Although development of a smart-bin prototype is taking place, behavioral change strategies to foster a willingness to reduce waste must take place along with technological interventions.

Japan’s declining population has caused changes in the amount and characteristics of municipal waste. In order to optimize waste incineration plants as a countermeasure to this problem, we analyzed the performance of the integration of the plants with the Mechanical Biological Treatment (MBT) system. In the integrated system, food waste and sewage sludge from waste incineration plants, sewage treatment plants, and industrial facilities were mixed and fermented to produce methane gas. In this study, we evaluated the environmental and economic performance of the integrated system in four case scenarios. The integrated system is located in Ichihara City in Chiba Prefecture, where the Keiyo Coastal Industrial Zone is located and where petroleum and chemical industries are concentrated. The MBT system in which the heat generated from the incineration of waste was transferred to the Keiyo Coastal Industrial Zone was found to be the best. This method could reduce CO₂ emissions by 1341 t-CO₂/Y, and the annual cost was the lowest at 1.60 billion yen/Y. However, the results of the sensitivity analysis of the food waste ratio and the piping distance suggested that it may be impossible to obtain appropriate evaluation results without considering the regional characteristics.

Due to aging and depopulation, cities in Japan struggle to maintain their municipal waste collection services. These challenges were exacerbated by the pandemic. To overcome these challenges, a prototype of collective and contactless waste collection technology has been developed. However, its acceptance by society is unknown. In this study, we surveyed Japanese people’s preferences regarding household waste disposal. The results showed that older adults (older than 60) are willing to walk longer (more than 2 min) to carry their waste to the disposal site than younger adults. They are also less concerned about the risk of disease infection from touching other people’s garbage than younger respondents (at a 0.24 count ratio). Other significant findings are that people who live alone prefer the temporary disposal site to be placed more than one minute away from their house (at a 0.19 count ratio). People living alone also produce less plastic and packaging waste than larger households. With more Japanese older adults living alone because of the scarcity of older-adult care facilities, we proposed two waste collection strategies that can allow for the implementation of more collective and automatized contactless waste pickup technology. Each design poses different challenges, such as the need for residents’ cooperation and a higher energy supply. However, they also open new opportunities, such as encouraging active aging and using renewable energy.

Title: Environmental and Economic Evaluation of a Mechanical Biological Treatment System for a Small and Medium-Sized Waste Treatment Facility Considering the Karatsu Smart Disaster-Resilience Base Construction Project | Keywords: waste management, sewage treatment, disaster resilience, methane-fermentation, mechanical biological treatment | Author: Akihisa Ogawa, Andante Hadi Pandyaswargo, Daiki Yoshidome, and Hiroshi Onoda

We conducted a survey about the feasibility of introducing MBT (Mechanical Biological Treatment) systems for waste incineration facilities linked with sewage treatment facilities. We focused on this topic because the decline of Japan’s population has caused the need of expanding service area of waste treatment facilities and optimizing the efficiency of energy use. From the questionnaire surveys distributed, we received 64 responses from waste incineration facilities, mainly in cities designated by government ordinance, and 78 responses from sewage treatment facilities. Our analysis results showed that 4.7% (3 cases) of incinerators and 3.8% (3 cases) of sewage treatment facilities have the possibility of installing both incinerators and sewage treatment facilities, which is unprecedented in Japan. Municipalities with more frequent communication between departments tended to choose the same pattern we offered, suggesting the importance of inter-departmental cooperation.