A proposed total separation index of a physical separation system used for more than three products was reviewed based on five conditions described by Schulz. That consideration showed that no total separation index of a separation system fulfilling all required conditions has been proposed to date. Furthermore, the total separation efficiency of an n-product system was confirmed to be expressed by the formula of m=d^1/(n−1) using the determinant, d of a recovery matrix. The index of m is exactly the total separation efficiency predicted by Aoki. This index is demonstrated to fulfill all five conditions. Moreover, it has the physical meaning of a perfectly separated feed rate, thereby enabling the extension of an n-product system. This extended separation efficiency, ESE and universal separation efficiency proposed by Salama were compared through a simulation using random numbers.

View full abstract

A comparative study of ASR treatment and recycling was conducted to evaluate the impact of four scenarios : landfilling, incineration followed by landfilling, melting followed by landfilling and melting followed by heavy metal recovery. Considering global warming, acidification, hazardous chemical substances (human toxicity), eco-toxicity and waste volume (landfill space occupied) as impact categories, the life cycle impact of each scenario was assessed based on an inventory of data obtained from the melting treatment of ASR and other processes and by making use of evaluation coefficients given in LIME2, which is a new version of LIME (Life cycle Impact assessment Method based on Endpoint modeling). Melting had the demerit of emitting more greenhouse gas than landfilling or incineration, but its merits of causing less damage to human health due to its smaller discharge of heavy metals and of requiring less space for landfilling outweighed this demerit. The difference between the merits and the demerit was larger when their effects on the ecosystem (biological diversity) were considered. It was found that the heavy metal recovery of fly ash in the melting process had a significant impact on the suppression of heavy metal discharge.

View full abstract

In many developing countries economic development and the trend toward urban concentration creates a crisis situation where the issue of waste management is concerned. Central and local authorities, where this problem is supposed to be handled through appropriate management, are facing many serious challenges. The situation of how to deal with waste and the attitudes citizens have toward it has become very grave in many cases.
This paper discusses approaches to raising environmental consciousness and developing pro-environmental behaviors among citizens in order to work on the waste problem, with public cooperation. The paper looks at the concept of environmental governance using a case study on waste issues in Sri Lanka.
Through fact-finding surveys and analysis of a comparative questionnaire, the results show there is a high level of environmental consciousness among the public ; there exists a possibility for behaviors to be corrected if citizens can put their trust in the local authorities ; and lastly, there is a lot of room for improvement regarding efforts to get citizens cooperating with the authorities on these issues.

View full abstract

The prediction of leachate quantity is essential for the planning of leachate treatment facilities when planning MSW landfill sites. It is also thought to be essential in comparison to precipitation to predict the quantity of moisture generated by the MSW biodegradation process in semi-aerobic landfills in developing countries that primarily handle the direct disposal of MSW.
Past research results have clarified that the moisture generated by the biodegradation process in semi-aerobic MSW landfills in their early stages is significant in comparison to precipitation, depending on landfill conditions.
In order to devise a method for predicting the moisture quantity generated by the biodegradation process, the authors investigated the application of the estimation method used for CH₄ emissions from solid waste disposal sites described in the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. This was based on past experimental data collected with a large-scale lysimeter filled with MSW at a semi-aerobic landfill.
The results demonstrate that, with appropriate parameters, this estimation method has potential to be applied to the prediction of the moisture quantity generated by the biodegradation process in semi-aerobic landfills.

View full abstract

[in Japanese]

View full abstract