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To use the molten slag derived from municipal solid waste, the method of decreasing environmental safety and the lead content on a slag was examined. It can use as a concrete raw material because there are a few changes in the concentration of SiO2 , Al2O3 and CaO contained in the molten slag. Enough control is necessary because a change in the Pb content is large. As for the concentration of Pb, Sn and Zn in the molten slag, it found that positive correlation was shown. It can think about the cause increasing Pb content in the melting slag with the solder, the flint glass and the light bulb and porcelain. The plastic other than food packaging contains trace amounts of the heavy metals. The separation of these wastes is necessary for the decrease in Pb content of the molten slag.

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This study examines expansive melted slag of waste were treated with chemical, and discusses the utilization as fine aggregate for concrete. It was verified that the concrete using unexpanded treatment melted slag of waste has good quality, when fresh and when hardened and durability. Furthermore that unexpanded treatment was availed concrete of steam curing.

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Recycled concrete aggregate is obtained by crashing and grinding demolition concrete generated and then seiveing it by more than 5mm to 40mm. Huge amount of concrete waste powder less than 5mm is generated from the process to make recycle concrete aggregate. Recycling on slag aggregate for concrete to melt waste concrete powder with fly ash and limestone powder is studied. the composition of raw materials is adjusted to slag at low molten point and after calcinating raw materilas at 1350degree centigrade with an electric furnace, melton slag has the density (more 2.5 g/cm3) satisfied by JIS A5031:2006 and it is suitable for concrete aggregate.

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Appropriate operation method for inner water of offshore landfill sites was evaluated. From a result of numerical analysis, it was clarified that the inner water level should be controled to a height under mean sea water level of outer sea. A intermediate tank model test was able to provide that a underground drainage pipe which was installed at upper region in the offshore disposal site can collect deeper inner water.

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The region where most of landfilled wastes becomes the shredded residues (from crushing processing) of municipal incombustible solid waste and municipal bulky solid waste, therefore use of incineration residue for the raw material of ecocement and waste melting facilities.Moreover, making the incombustible shredded residue to resources is expected to be investigated in the future. In this report, properties of the shredded residue of incombustible waste and bulky waste and leaching characteristics of the pollution element at the reclamation were examined. In this investigation, a composition investigation, various leaching tests and column tests were examined, and it has been understood to contain a lot of plastic in the composition investigation. At the leaching tests, heavy metal was detected and that concentration was low. Long-term characteristic of heavy metal release was confirmed by the column test on over 200 days.

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Organic compounds, which are detected with GC/MS and/or LC/MS, containing landfill leachate in final disposal of waste are analyzed the relevance between their physico-chemical properties by making phase partition diagram of their compounds in air/liquid(water)/solid phases.

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1,4-dioxane was known as cancer-causing substance and one of the chemical substances which was detected at high density / high frequency in environmental water. Because 1,4-dioxane had properties of low biodegradation and high hydrophilicity, it was known that 1,4-dioxane was not removed enough by the conventional water processing technology that was mainly biodegradation and separation. In this study, the experiments on decomposition of 1,4-dioxane in leachate from landfill site by ultraviolet rays / hydrogen peroxide method (UV/H2O2) were performed and the decomposition characteristics were examined. Consequently, it was clarified that 1,4-dioxane decomposed by UV/H2O2 immediately. In addition, the model on decomposition of 1,4-dioxane and H2O2 and coexistence organic matter in UV/H2O2 reactor was constructed, it was simulated with a computer. As a result, the calculation value agreed with the experimental value very much. Namely, the prediction of the processing water and the detailed design of UV/H2O2 reactor were enabled with the model that was constructed this time.

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In the treatment by ultraviolet rays and ozone (UV/O3), In order to understand the ozone absorption characteristics, the analysis model was built for the multistage type UV/O3 reactor which connected the parallel flow ozone bubbling reactors of internal irradiation type in series. The parameters required for the analysis model were obtained by the laboratory experiment using city water and simulated waste water. Consequently, the present model was confirmed to be effective in obtaining the ozone absorption rate in the multistage type UV/O3 reactor.

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The boring method, which is a conventional method, is one of the ways to install a well for removing leachate and gas in the waste layers. In this method, a hole is drilled on the waste layers and a perforated pipe is installed. Since this method is difficult and expensive, there are many landfills that have been remained untouched for a long time. To solve this problem, the new method of well installation has been developed. In the new method, the tip of casing is removable. Only casing is removed after a perforated pipe with the casing is placed in the layers; therefore, the wastes in the layers do not come out, and water is not needed to drill the hole. In the method, it is less expensive and takes less time to install the well comparing to the conventional method. If this method is used for a ventilation facility in order to stabilize the wastes, it is possible to shorten the maintenance time and lower the cost of maintenance.

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Although the monitoring of leachate quality is essential to get necessary information regarding the judgment of cessation of landfill aftercare, which leachate is reliable and reflects actual state of landfill is not certain. In this study, leachate sampled from 68 gas ventilation pipes were analyzed and their spatial distribution and fluctuation along sampling interval were investigated. Leachate characteristics varies significantly by each pipe but seems to reflect the waste condition of nearby location. By eliminating points at where leachates are fluctuated by rainfall, percentages of area where stabilization is well promoted was estimated. In studied landfill, the percentage of the stabilized area estimated was nearly 60%.

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In order to confirm the spatial position of waste asbestos in landfill sites, small bore sounding and antiscattering boring were conducted at areas disposed of waste asbestos. Horizontal and vertical positions of waste asbestos observed by sounding were consistent with that by boring. During sounding and boring, fiber counts of asbestos in neighborhood air were in range of background air. These showed that a series of methods in this study can use for on site confirmation of the position of waste asbestos in landfill sites.

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