Recently, a fundamental conflict with MSW disposal is common in each municipality. There are two general ways in which to dispose wastes with energy recovery: MSW incineration and an RDF system. The RDF system has been receiving attention as a new system at the moment.
This paper is a total evaluation of an RDF system with energy recovery that uses environmental loads and a additional social benefit analysis like energy savings, air pollution reduction and so on. In addition to the RDF system, it is compared with the MSW incineration system.
The object of analysis includes a total operating process of systems from MSW transportation to final disposal (landfill) . Main processes include formed RDF manufacturing, incineration, the generation of electricity and the recovery of steam.
As a result, the existing RDF system needs partial improvement of the operating process in order to reduce environmental loads. However, it is possible to say that the theme is a low environmental load level per energy production (1 kWh) because the system has a high energy recovery efficiency. It is also possible for an economical viewpoint to be added to the above mentioned social benefit items.

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It is expected that sewage sludge will continue to increase in the future as a result of the development of sewer construction activities. At present sludge is treated as industrial waste and buried, but the availability of disposal locations is becoming more limited every year. Sewage sludge is increasingly burnt or melted to reduce its volume, thereby forming a sewage sludge melting slag.
The purpose of this study was the investigation of application of the sewage sludge melting slag to self-compacting concrete. An experiment involving the fresh and hardening properties was carried out, the results of which clearly revealed that the sewage sludge melting slag powder was a useful admixture for self-compacting concrete, and that the harding concrete characteristic is almost the same as for normal self-compacting concrete.

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The purpose of this study was to investigate how residents changed their evaluation of a new collection system of strict separation between recyclable and non-recyclable materials. The new system was introduced to three areas successively over 15 months. The social survey was conducted as a quasi-experiment to compare residents' evaluations of three areas before and after the system's introduction. Each group of 210 respondents were selected from one area before the introduction and two areas after the introduction.
The main results were as follows. The general evaluation of the collection system became more positive after its introduction. Before introduction of the new system, residents, who read the town newsletters and participated in a special neighborhood meeting, evaluated the social benefits of the new system more positively. After introduction, the residents, who now had a behavioral commitment to the new system, evaluated the personal costs of the system more positively.

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We have described a chemical composition of metal particles formed in a mixed (bottom/fly) ash surface-melting furnace. These particles were divided into three groups according to particle size. The first group, having mm sized particles, were separated from slag formed by quenching the molten ash with water. The second group, having hundreds μm sized particles, were separated from slag after crushing. The third group, having a few-10μm sized particles, were wrapped in slag or adhered to slag.
The major elements of the first group were Fe, (Fe+Cu) by X-ray fluorescence. Metal Fe, metal Cu and (Fe₄Cu₃) compound were detected in metal particles by X-ray Diffraction. The second and third group were analyzed by an energy dispertive spectrometer. These contained various metal components such as Fe, Cu, Cr, Si, Co, Ni, Zn, Sn, Sb, Pb etc. The dominant particles, consisting of Fe, (Fe+Cu) . (Cr-Fe-Ni), (Fe-Co-Ni), (Fe-Cu-Sn-Sb), (Fe-Sn), (Ti-Sb) and (Pb-O-S-Cl) were detected in some metal particles.

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Two types of advanced oxidation processes, O₃/H₂O₂and UV/O₃/H₂O₂processes, were tested to evaluate their performances of decomposing dioxins contained in a landfill leachate. In this experiment, the concentration of total dioxins reduced from 6, 500 pg/l of the raw water to 3, 500 pg/1 and 1, 900 pg/l of the treated waters by the O₃/H₂O₂and UV/O₃/H₂O₂processes, respectively. Comparing the decomposition data profiles of each dioxin homologue, both methods showed nearly the same performance for low-chlorinated compounds. But for high-chlorinated compounds, the UV/O₃/H₂O₂process showed a better decomposition performance than the O₃/H₂O₂process. Ninety one percent of total TEQ of the raw water was composed of tetra, penta and hexa-chlorinated compounds and the TEQ deriving from high-chlorinated compounds was small. From our data, the UV/O₃/H₂O₂process was more useful for the removal of total dioxins, but the O₃/H₂O₂process was showed to be useful for reducing TEQ which expresses the actual toxicity of dioxins.

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An equilibrium chlorine-gas concentration from some chlorides, NaCl, KCl, CuCl, NiCl₂, ZnCl₂and FeCl₂was studied. The result showed that chlorine-gas liberation from NaCl and KCl can be ignored. The equilibrium concentration of CuCl increased as temperature decreased from 1, 000 to 500 K, while other chlorides displayed the opposite tendency. The concentration from CuCl was about 10³-10⁵ppm at 500 K in the presence of 0.1 atm O2, but others were 3-100 ppm. The result also showed that the order of chlorides characterized as a high chlorine gas producer was CuCl, FeCl₂, ZnCl₂and NiCl₂.

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