The cost-effectiveness of PCB waste destruction projects were compared with those of dioxin reduction measures for municipal solid waste incinerators (MSWI) . An environmental fate and exposure model was consistently applied to both of the projects to calculate the unit costs of reducing dioxin exposure. Project costs were taken from previous studies. Project effects (reduced exposure to dioxin-like compounds) were estimated by using an environmental fate and exposure model coupled with estimates for reduced emissions from previous studies. Cumulative reduction of exposure up to 30 years was selected as the time frame to evaluate the cost-effectiveness for the current generation, which will pay the project costs. The estimated reductions of exposure by PCB waste destruction projects were 0.8g-TEQ, 5.7g-TEQ and 1.6g-TEQ for air, water and soil emissions, respectively, and that by dioxin reduction measures for MSWI facilities was 3.5-11g-TEQ. Unit costs of reducing exposure to dioxin like compounds for PCB waste destruction projects was 27-190 million yen/mg-TEQ and that for dioxin reduction measures for MSWI facilities was 67-210 million yen/mg-TEQ. The PCB waste destruction projects were shown to have about the same cost-effectiveness as dioxin reduction measures for MSWI facilities.

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In order to evaluate the feasibility of using recycled materials as a diet for red sea bream, a pelletized diet was manufactured and its effectiveness compared to a commercial diet.
The composition of the red sea bream diet was made up of various raw materials that were selected from food leftovers which normally go to waste in urban areas. These included okara, a residue from tofu manufacturing; fish paste, a residue from fish cake manufacturing; and sushi, left over at sushi restaurants. These materials were dried using a flash dryer with a disintegrator and then pelletized after adding fish bone and some other products. The recycled diet composition was analyzed and fed to red sea bream for 63 days, results were compared to those on a commercial diet. The recycled diet was found to be as effective as the commercial diet and able to be used as a diet for cultured red sea bream. The production process was optimized and the estimated selling price is similar to that of the commercial diet based on a production rate of 6 tons per day and an IRR of 10%.

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In order to manage the complicated waste paper collection and wholesale system, the activities of companies in this field were analyzed and modeled using Quantification Theory III, which converts qualitative information into quantitative parameters.
Characteristics of each company were categorized based on a questionnaire that focused on waste paper collection activities. A work-flow model of the collection system was then developed.
Companies were grouped into three kinds of collectors and wholesalers.
It was found that the different systems for material flow of waste papers are different depending on their sources.

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The purpose of this study is to show the effectiveness of transparent garbage bags in household waste reduction, and to consider whether they merit introduction in the process of reforming waste collection systems. There are many types of household waste collection systems operating in Japan, including the usage of garbage bags. Each local government must decide what kind of garbage bag should be used. Some local governments choose the designated garbage bag system, and others opt for what is called the “free system.” The transparent garbage bag system has more widespread usage in the Kinki area as compared to other areas. Per capita quantities of household waste were compared in 33 cities where either the transparent garbage bag system, the designated garbage bag system, or the free system has been implemented. It was found that the transparent garbage bag system had some effect in reducing household waste. Surveys of household waste before and after the introduction of the transparent garbage bag system in Hirakata City, Osaka, indicated a noticeable reduction in per capita quantities of food waste (excluding unused food), newspapers, magazines, clothes, and some types of packaging.

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Due to the fact that organic garbage with high water content decreases the low heating value of municipal waste, it is thought that this waste should be composted and/or fermented to produce methane after being separated out from other types of municipal waste. Remaining wastes should be incinerated to generate electricity in order to utilize their high heating value. In this study, CO₂ emissions from the process of garbage treatment in the proposed system were first calculated. Next, CO₂ emissions from the present municipal waste incineration system (with power generation and ash treatment) were compared with CO₂ emissions from the proposed system. The effect of fertilizer production on the reduction of CO₂ emissions was taken into consideration. The results showed that for most of the proposed system, the CO₂ emissions that increased through energy consumption in the garbage treatment process were mostly compensated for with the reduction of CO₂ emissions in the power generation using other municipal wastes and the fertilizer production process. By comparison to the present incineration system for municipal waste, the garbage separation strategy is thought to hold an advantage. However, in the case of the composting system distributed on a small scale, CO₂ emissions increased with the use of urban gas because the first fermentation could not be compensated for with the above advantages.

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We conducted experiments on dry batteries that contained mercury and were buried in waste in small lysimeters for 15 years. We dismantled the lysimeters after 1 year, 2 years, 7 years, and 15 years from the start of the experiment, and measured the corrosion levels of the dry batteries and the behavior of mercury leakage from them into the waste layers.
The corrosion of the dry batteires in landfill during the first two years was caused mainly by the leachate generated in the different landfill types, and electrolytic corrosion caused by the retention voltage of the dry batteries.
After those initial years, during which the retention voltage was consumed, the period of time in the landfill became the main factor for the corrosion of the dry batteries. The longer the dry batteries remained in the landfill, the more extensive the electrolytic corrosion.
We confirmed a little migration of mercury into leachate ; however, we also noted that mercury vapor was generated that migrated into waste layers.
Even after 15 years from the start of the experiment, mercury levels near the dry batteries were still high. However, the mercury levels just above and just below the waste layers containing the dry batteries were low. From these results, we concluded that mercury has a tendency to remain near dry batteries even after many years.

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Local residents are opposed to landfill projects because of doubtful long-term safety: groundwater may be contaminated by leachate or processing water. Continuous long-term monitoring is necessary to accumulate data on substances that affect natural populations because leachate contains a complex mix of unknown substances. We have devised a method for monitoring drainage using an ecosystem model and medaka. We studied the effect of short-term exposure to leachate or treated leachate on the reproductive capability of medaka.
Estrogenic substances—benzophenon, nonylphenol, and bisphenol A—were detected in the leachate sample. Leachate toxicity is inferred to result from compounds that make up the total organic carbon (TOC) rather than from ammonia or salts. Untreated leachate with a short reclamation period and a high TOC was very toxic. Untreated leachate with a TOC of 1, 360 mg/L was diluted to 2, 4, 8, and 16% with water. Then adult fish were exposed to it for two weeks. The HSI of adult fish increased in 8 and 16% leachate compared with the control. These leachate samples and treated leachate did not induce VTG in medaka. Moreover, normal reproduction of medaka was blocked by exposure to 2% leachate and treated leachate. Further studies are necessary to monitor long-term effects of leachate and treated leachate on medaka.

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It has already been confirmed that the removal and capture of lead ions by molten slag and coexistent anions is dependent on the insolubility of the lead which was converted into basic lead carbonate, a kind of lead oxychloride, laurionite and lead sulfate.
In this investigation, we studied the contribution of carbon dioxide toward the formation of basic lead carbonate (2 PbCO₃⋅Pb (OH) ₂) and the effect of coexistent molten slag under the influence of carbon dioxide to reduce further lead concentration. Consequently, carbon dioxide in the atmosphere was converted into carbonic acid ions in water and it was contributed to the formation of basic lead carbonate with molten slag. Basic lead carbonate, laurionite and lead oxide were converted into lead carbonate in distilled water, and lead sulfate was converted into lead carbonate in a 1% sodium hydroxide solution. However, after carbonation, when the pH value of the solution was reduced, the lead concentration of the solution was higher than that of the solution before carbonation. However, when carbonation was carried out with the coexistent crystallized molten slags, the pH value of the solution was not much reduced. It was confirmed that coexistent crystallized molten slag effected the reducing of lead. The reason for this was that the pH value of the solution was not much reduced from the neutralization of hydroxide ions and the buffer action of calcium ion by the molten slag and the slag's adsorption.

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In order to identify factors that would encourage the reduction and reuse of electric home appliances, a questionnaire survey was carried out on past and future consumer behavior in disposing of TV sets, air conditioners, refrigerators, washing machines, PCs, microwave ovens, vacuum cleaners, and VCRs. The results showed the following typical patterns of disposal behavior: the most influential factor was mechanical failure; reuse was seldom carried out, however, products with mechanical failure could be reused if there is demand in the market ; reuse did not necessarily have a significant advantage in terms of a products' long-term use ; it was difficult to repair or reuse a product whose life-time had already passed over a certain period of time; even though a consumer has motivation for repair and reuse, social systems discouraged such behavior; a consumer's willingness to continue using the same product faded considerably discouraged when the product's condition become degraded. We also discussed measures might be taken to encourage consumers to reduce or reuse electric home appliances.

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As the furnace wall of the spiral flow melting furnace is exposed to high-temperature combustion gas and molten slag, a water-cooled self-coating structure is applied to extend the wall's life.
We examined the features of a self-coating structure with a heat balance model which is composed of variables such as heat flux, thickness of slag layer, and gas temperature. The calculated heat flux was confirmed to agree with observations for the temperature range 1, 450-1, 550°C.

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