Combustion experiments with the injection of an iron oxide catalyst using an intermittently-operated and mechanical batch-type incinerator for municipal solid waste were carried out. As a result, it was observed that the oxide injection had a notable suppressive effect on dioxin formation and the removal function of hydrogen chloride was highly promoted by the combination of calcium hydroxide and the catalyst.
The dioxins in combustion flue gas decreased to 20-30% of the quantity of the formation without the iron oxide catalyst, and the iron oxide catalyst decreased the total quantity of dioxins emitted from the incinerator, including fly ash.
Because the formation of iron chlorides has a strong influence on dioxin formation, the possibility of the formation of iron chlorides from the iron oxide catalyst was studied thermodynamically.

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The overall aim of this study-in-progress is to obtain a quantitative grasp of the environmental loading imposed by the construction of buildings, which is closely related to global environment issues, with the aims of saving energy and resources and reducing waste. As a step towards this goal, we investigated the fixed resource consumption, energy consumption, CO₂emissions, and waste discharges resulting from construction of a model 14-story steel-structure office building with two basement floors and one penthouse floor. Details of the resources used in carrying out about 4, 000 different construction tasks were collected. Various techniques were used to classify the materials used in these tasks into 19 basic types, and based on this classification, a resource investment index (kg of each material per m²) was derived. The total resource investment in the building, (about 2, 800 kg/m²) and also in six similar buildings of different sizes was then calculated. On the basis of the calculated resource investment in each building, the energy invested in construction was calculated from available figures of standard energy input. This was then converted into a figure for CO₂emission, which turned out to be about 435 C-kg/m². This high output value seems attributable to the use of iron and cement not only in the superstructure of steel frame construction but also in the steel frame and reinforced concrete composite substructure incorporating two basement floors (for district heating and cooling facilities, and a parking area) . The amount of waste discharged during construction of the model building was also studied. Consumption/discharge ratios were defined for 27 materials used in 10 different tasks, and these were used to calculate the waste generated in carrying out 785 construction processes. The total waste discharge as calculated in this way was compared to values derived by multiplying the floor area of the building by mixed waste values for another building with the same attributes.

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Any production activity including recycling of waste materials and consumption emits waste, which is treated by waste management sectors (recycling and disposal) . Goods producing and waste management sectors are mutually interdependent through the flow of goods and waste. Looking at this interdependence is important to resolve the question of whether recycling of waste results in an overall increase or an overall decrease in environmental emissions. A Waste Input-Output (WIO) model is presented, which describes this interdependence in a quantitative manner. The model evaluates environmental emissions associated with a given matrix of technical input-emission coefficients representing the technology and institutions, and a given vector of final demand representing the lifestyle. This paper reports results of the estimation and application of the WIO model for Japan that consists of data from 60 industry sectors, 24 waste types, four waste disposal methods (shredding, incineration, melting, and landfill), and two types of environmental emissions (carbon dioxide and landfill volume) . The model was used to evaluate economic and environmental effects of alternative recycling and waste disposal options, which include power generation from waste heat, and the use of waste plastics as materials for steel production.

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To develop an environmentally benign technique for treatment of CCA-treated wood, the effects of temperature, pressure, and flow rate on the extraction efficiency in the extraction of heavy metals by using supercritical CO₂containing acetylacetone as a chelating agent were examined experimentally. It was found that high temperature, high pressure, and low flow rate greatly improved the extraction efficiency. Acetylacetone added as a chelating agent markedly enhanced the extraction yield, apparently due to the formation of metal-chelating compounds. This study suggests that metals contained in commercially used CCA-treated wood can be extracted by using supercritical CO₂with acetylacetone.

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Nowadays, construction of landfill sites has become more difficult because of the opposition from residents. The reasons are : anxiety about groundwater pollution ; doubts about the results of site selection ; suspicion of the operating bodies, and so on. To settle this problem, the '1997 Amendment to the Waste Management & Public Cleansing Law' obliged all solid waste disposal facilities to carry out living environment assessment and to make the results of the assessment available to the public. But living environment assessment only can not settle this problem completely. Residents' participation in planning and site selection for landfill sites is also required. The objective of this study is: to integrate the process of site selection for landfill sites, through three real examples of site selection, by developing a procedure of site selection based on geological and hydrogeological conditions, and introducing public participation into the procedure. Effectiveness of this process is also examined through three other real examples of site selection, where opposition from residents has occurred. As a result, it is supposed that : carrying out site selection ; making proper information available to the public ; and holding public hearings ; may prevent the escalation of opposition from residents caused by poor information, and promote mutual understanding.

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