In this study, we investigated an electronics recycling plant in Japan. At the plant, dismantling and shredding processes of waste television (TV) sets with highest polybrominated diphenyl ether (PBDE) concentrations considered in their housing rear covers were especially focused. Air monitoring for BFRs {i.e., PBDEs, tetrabromobisphenol A (TBBP-A) and hexabromocyclododecane (HBCD)} and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/DFs) was conducted in the above two processes for TV sets. During investigation, technical countermeasures to reduce particle dust were introduced by the plant and a difference of BFR and PBDD/DF concentrations and patterns in air samples was evaluated before and after taking the measures. Additionally, in order to know sources of occurring BFRs and PBDD/DFs in the air at the dismantling hall, a dust sample collected from the air was compared with TV inside dust and TV housing cover samples in terms with their chemical compositions. Finally, air emission amounts and factors of PBDEs from the two TV recycling processes were calculated by using the obtained data.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

This research proposes a method for searching for an optimal strategy of the municipal waste management (MSW). Waste treatment technologies such as incineration and landfill should be examined not in an individual manner but in an integrated one when an optimal management strategy is searched for. Thus, the Hokkaido University Integrated Waste Management model (H-IWM) is employed. Because the change of MSW management strategy affects the other industries, the waste input-output model (WIO) and H-IWM are integrated. The integrated model is nonlinear in variables because H-IWM is nonlinear. It is thus difficult to stably obtain an optimal solution to the model. This difficulty is overcome by developing a linearized version of H-IWM.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Recently, various environmental problems, such as global warming, have arisen and development of sound material-cycle society has been required. Kitchen waste recycling is one of measures, but most of them have been incinerated, although large amount of kitchen waste is discharged. And also the reason why the kitchen waste recycling isn't promoted is not cleared. Therefore, in this study in order to grasp of promotion factors for kitchen waste recycling, a current situation of the kitchen waste recycling in local governments in Japan was investigated. Seventy percent of the local governments have a support system to each household although there were very few local governments which collect kitchen waste separately. A questionnaire investigation was conducted to the local municipalities which have a kitchen waste recycling system, or not, and issues which they were raising were grasped. Based on the data, I analyzed the issues to be solved in order to promote the kitchen waste recycling as follows. (1) Construction costs and administrative and maintenance costs, (2) Increase in the expense according to separate collection of kitchen waste, (3) Demand of recycled material, (4) Measures against a bad odor from recycling facilities, and (5) Shortage of information service.

View full abstract

[in Japanese]

View full abstract

Hazardous waste management systems have been developed in industrializing Asian countries. This paper compares about the establishment of regulation on hazardous waste, the amount of hazardous waste generated, the responsibility of waste generator in the case of contractor's illegal disposal, and manifest system in South Korea, China, Taiwan, Philippines, Vietnam, Thailand, Malaysia and Indonesia. Waste generator is imposed with full responsibility about illegal disposal of contractor in Malaysia or China. South Korea and Taiwan government use e-manifest system to identify companies dumping waste illegally or store waste beyond the capacity.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

This article examines the meanings and issues of the introduction of Benchmarking practice to municipal waste management. By adopting the concept of Asymmetric Information (more specifically Signalling) which is often discussed in Microeconomic theory, we show that the nature of asymmetric information may arise between the local governments which use Benchmarking to demonstrate their performances and have temptation to overstate their goodness of their services and those who such as citizens and other stakeholders receive the information. Whether or not Benchmarking would work heavily depend on the reliability of input and output information that Benchmarking is involved. We also argue that introduction of benchmarking should deal with not only the economic indicators but also social indicators which aim to contribute to the discussion of how municipal waste managements as well as their local communities should be.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

Some reports say this system clarifies waste generator's responsibility, stimulate waste separation for recycling, and lead to waste reduction. But the anxiety on the increase of cost of waste collection and transportation exists. So the objective of this study is to analyze the characteristics on municipal solid waste collection and transportation between the different collection methods by mutual exploitation of Global Positioning System (GPS) and Geographic Information System (GIS) in one district in Fukuoka city, Japan. As a result, in case of bring collection method, the number of peoples is very small.The collection vehicle stops every time the collection crews throw waste bag into the collection vehicle. In case of curbside collection method, on the contrary, the vehicle does not stop and keep moving forward in the middle of collecting. In case that less than 20 kg of waste is collected from each collection point, the collection vehicle does not stop. But it is not clear the relationship between the distance to the next collection point and whether the collection vehicle stops. While the collection crews are collecting waste disposed in the collection points for one residence, the average running speed is little higher than those of the collection points for multiple residences.

View full abstract

Cost comparison on different hauing systems; hauled container system and stationary container system, for plantation biomass was made. It was found that hauled container system was better in most case and showed lower cost than stationary container system.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The procedures for the selection of landfill disposal site should be not only rational but also simple for the consensus building between all the stakeholders. In this paper, the method for the second selection of the procedures in which a few sites are selected considering disastrous risk, environmental impact and social/economic interests of neighbors through given data is proposed which is easy to account to the stakeholders. The method has been applied to the case study of Kinan region in Wakayama prefecture to be useful sufficiently.

View full abstract

Based on the Fundamental Law for Establishing a Sound Material-Cycle Society, moves are now accelerating toward creation of a society with an environmentally sound material cycle, less consumption of natural resources and less burden on the envitonment. The building of a renewable society with a sound material cycle demands that consumption of natural resources be controlled,and that the amount of landfill waste destined for final landfill sites be kept at aminimum.In response to these emerging demands, final landfill sites are increasingly required not only to process landfill dispozals, but also to play an active role in reusing recyclables while minimizing impact on the environment. The NPO Landfill Systems and Technologies Research Association of japan has defined the environmentally friendly or Eco Landfill Site as a disposal fasility that is compatible with a renewable society and kind to both global and local environments. The Association is now investigating what constitutes such a landfill site.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

We analyzed the life-cycle inventory of mercury for some types of fluorescent lamps and bulbs, with various patterns of power stations or management options at the end of lamp life. The result suggested that taking into account the amount of mercury released during electricity generation from coal fired power stations, mercury-containing fluorescent lamps, especially high performance products might reduce the total amount of mercury emission to the atmosphere compared to bulbs which themselves are mercury free. We also cleared effects of the energy efficiency of lamps, the recovery of mercury from end of life products, and the improvement of gas cleaning at power plants.

View full abstract

[in Japanese]

View full abstract

A case study on optimum utilization system of biomass/waste considering the greenhouse gas emission was carried out, on the basis of supply-demand balance of nitrogen and phosphorus in farmland. As for the GHG emission, it was 12,650 kt-CO2eq/yr for the present model (surplus fertilizer application) and -6,790 kt-CO2eq/yr for the future model (minus indication means energy production). The GHG emission would be considerably reduced, by the energetic utilization (methane fermentation and gasification) of the biomass incinerated and disposed at present, and by the hybrid utilization of biomass. The hybrid utilization means the integrated system among the methane fermentation (including energy recovery) of the biomass composted at present and the recirculation of the fermentation residue into farmland. But the changing of model parameter would affect the calculation result of case study largely, so that the setting of model parameter considering the local situation would be important and necessary.

View full abstract

Recently, utilization of kitchen garbage is demanded as part of promotion a recycling-oriented society, but the recycle does not advance very much. Especially in Metropolises, there is few examples that local governments adopt kitchen garbage recycling system though there is much quantity of kitchen garbage in the city.Therefore in this study, I clarified kitchen garbage recycle problems and intention of local governments and the citizen by questionnaire and hearing research for them. In accord with the research, I made six scenarios of biogasification system.In addition, I compared the recycling system based on each scenario with all kitchen garbage incineration system about economic and environmental aspect, case study of Sapporo city. The results showed that there isn't so much of a difference between the recycling system and all kitchen garbage incineration system about economic aspect, and that the more amount of recycled kitchen garbage increased, the more amount of environmental load material emission such as carbon dioxide decreased.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract