We developed a new gas purification system for MSW incinerators. By reburning the whole exhaust gas from the incinerator, dioxin entrained in the exhaust gas was thermally degraded then the gas was cooled down with a high-speed gas cooler or a heat exchanger to suppress dioxin reformation. In order to verify the system, we carried out fundamental experiments using a basic model and verification experiments in both an MSW and an industrial solid waste incineration plant.
Consequently, we verified that the system could reduce the dioxin concentration below the level between 0.1 and 0.01 ng-TEQ/m³_N. Furthermore, we revealed the following as technical data for designing the system : (1) Co-presence of fly ashes, HCl and dioxin precursors in the exhaust gas promotes dioxin synthesis and prevents dioxin from being broken down in the high temperature decomposition process, (2) In the cooling process, dioxin reformation depends on the time needed for the exhaust gas to pass through the temperature window (250 to 400°C), and (3) The maximum concentration of dioxin can be roughly estimated according to the concentration of [fly ash] [HC1] [2, 4, 6-trichlorophenol] ²in the system using a 0.5 second high-speed gas cooler.

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This paper studies the effective recycling of the construction sludge which arises during the construction of slurry type shields and earth pressure balance type shields.
With shield tunnels being frequently constructed, the quantity of the construction sludge has become remarkably copious. Processing of construction sludge by shield tunnelling is serious environmental problem.
In this study, a super absorbent polymer was added to the sludge in order to reduce the degree of fluidity. The stabilizer was mixed with the sludge to improve the strength of the sludge. The improved efficiency satisfied the second level standard which Ministry of Construction determined for the reuse soil ; 0.5% - 0.7% addition of the super absorbent polymer and the stabilizer 13%-18% mixture for the mass of the construction sludge.
The investigation was conducted to estimate the change in strength of improved sludge for a period greater than one year. It was found that improved long-term stability could be achieved in the modified sludge.

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We propose a method of analyzing data obtained by household questionnaire surveys, employing quantification theory. Through the case study in Tokyo metropolitan area, we quantitatively analyzed the waste generation structure as well as the factors pertaining to the awareness and action of waste discharge.
It is important to predict the quantity of municipal solid waste in the future and be also to grasp the actual awareness of waste reduction for the waste management planning. Thus our proposed method consists of following three parts, i ) ; analysis of waste generation structure using quantification theory type-1, ii) ; classification of the factors relating to the awareness and the action for waste reduction with quantification theory type-3, iii) ; analysis of waste reduction awareness with quan-tification theory type-2. In considering the case study with the questionnaire data, our approach starts analyzing the waste generation structure in households, finding the factors which relate to quantity and then describing the forecasting model of the amount of waste generated from each type of household. Moreover we show the process to classify the factors of awareness and actions into four groups. Finally we describe the factors relating to the awareness of waste reduction.

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Strained lees of soy-sauce made from whole soy-beans was desalted and dried for recycling as livestock feed stuff. Formulation of the feed using the finished product is flexible as 98% of the salt in the raw lees has been removed by desalting. The product can be used as a source of nitrogen in the feed formula. 581kca1/100g of energy especially composed of crude fat is included in the product which can also be effectively used for fattening. The product is microbiologically safe as microorganisms were not found in the product and water activity was under 0.3. The suitability of the dry desalted lees of soy-sauce from whole soy-beans for livestock feed was suggested by investigating quality in this study.

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