In order to verify the dioxins removal effect of sodium reactant, we measured the dioxins concentration at the baghouse inlet and outlet of the plant where chemical agent for acid gas treatment was updated from slaked lime to sodium reactant. The rate of dioxins by using of sodium reactant was higher than by using of slaked lime, and it was suggested that sodium reactant has some effect of the dioxins removal.

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Gaseous elemental and gaseous reactive mercury emitted from the incineration of automobile shredder residues (ASR) was monitored continuously. Most of gaseous mercury was reactive one before fabric filter (FF). Although 51% of total gaseous mercury was decreased by FF, concentration of gaseous elemental mercury was increased. It implied that the reduction of reactive mercury was occurred on the surface of FF. Emission factors of gaseous elemental and gaseous reactive mercury were estimated to be 59.4 mg-Hg/Mg-ASR and 39.3 mg-Hg/Mg-ASR, respectively. When any air pollutant control devices was not considered, these emission factors were increases to be 37.9 mg-Hg/Mg-ASR and 154 mg-Hg/Mg-ASR, respectively. If all of ASR in Japan was incinerated without effective pollutant control devices, total emissions of gaseous elemental and gaseous reactive mercury were estimated to be 30 kg and 0.1 Mg, respectively. When the emission of particulate mercury is counted, total mercury emission from ASR incineration increases to about 1 Mg.

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The unintentional formation and decomposition of PCN was investigated during thermal treatments of automobile shredder residue (ASR) and refuse derived fuel (RDF). By measuring of PCN in ASR, RDF, the emission gas, and ash, the PCN behavior and volume in ASR experiment were compared with those in RDF experiment. Furthermore major pathway of PCN was proposed on the basis of the congener-specific analysis.

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Crystalline phase of alkali washed fly ash was analyzed by X-ray diffractometry. Anhydrite (CaSO4), calcite (CaCO3), calcium chloride hydroxide (CaClOH), halite (NaCl), quartz (SiO2) and sylvite (KCl) were identified on the diffraction patterns of raw fly ash samples. After calcination at 900 - 1000 degrees, fly ash sample was decomposed and sintered to fragile cake, gehlenite, C3A and CA which were major crystalline phases of cement clinker grew up in the diffraction pattren. X-ray fluorescence analysis of 13 major and 5 trace elements in fly ash samples were developped using powder briquette method. The proposed method has been applied to the analysis of several fly ash samples. The main components of fly ash were Al2O3, SiO2, Cl and CaO. Several thousand ppm of Zn and Pb were included in the most of fly ashes. Cl and Br could be analyzed though their volatile characters.

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The survey of municipal solid wastes incinerators was performed and then the leaching test of the bottom ashes and the fly ashes after solidification processing and the metal content test were performed. Consequently, the amount of incineration ashes was of the order a stalker furnace(SF) > a fluid bed furnace(FBF) > a fluid bed type gasified melting furnace(GMF). About 100% of chloride ion was contained in FBF and GMF fly ashes, on the other hand about 90% in the SF. Moreover, the salt content of the bottom ashes increased with the furnace which is reusing the processing water of the landfill site to the cooling water of a furnace. Nine elements, such as sodium, were detected as a result of the leaching test. Copper was leached from the bottom ashes in incinerator except for the GMF. Almost all elements concentrations except iron, manganese and copper in fly ashes were higher than in bottom ashes as a result of the content test. In the incineration facilities which is reusing the processing water, sodium and potassium were condensed in the bottom ashes as the same chloride ion. Most harmful metal was caught by activated-carbon-treatment fly ashes in the GMF.

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There have been many efforts to establish the circulation type society in Japan. The national basic plans for the circulation type society mentioned securing new landfill sites by the renewals of existing landfills and three Rs (reuse, reduce, and recycle) are highly required. Because high concentrations of dioxins and heavy metals are contained in the minute particles of the wastes landfilled before the changes of the Landfill Law, separations of these minute particles are thought to be effective way for the renewals of the existing landfills. As the first step of these efforts, concentrations of the heavy metals and chloride at each particle size of the incinerator ash and fly ash before and after the washing using Waste Washing System (capacity, 1t/d) were examined. It was found that the elimination of those contaminants can be achieved over 50 % by separating out some ash size classes containing the contaminants. This method can be applied for the treatment of contaminated sediment and soil and it is planned to be used in the pre-treatment of landfilling and in the environmental remediation by improving the washing and fractionating efficiency of the Waste Washing System.

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The effective utilization of landfilled municipal solid waste incinerators residues (MSWIR) is required to prolong the life of landfill site in Japan. Incineration residues contain heavy metals such as, lead, cupper, and chromium. We have to develop the technologies to stabilize these heavy metals in order to achieve the effective utilization. Carbonation is one of the economical technologies for stabilization of the heavy metals. Carbon dioxide is generated easily in incineration plants without any additional energy. In the present research, we focused attention on the possible stabilization that caused by carbonation as result of weathering. The analyses of carbonic acid content, XRD, XAFS, X-ray analytical microscope were performed to MSWIR samples. The results have shown that landfilled MSWIR was highly carbonated in the area exposed to the atmosphere. Elution of lead from MSWIR was small in the highly carbonated area. Carbonate enclosing lead bearing fragments was estimated to prevent the elution of lead.

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

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We reported a new Ca removal treatment of leachate CO2 aeration method which uses low concentration CO2 instead of Sodium carbonate method. Merits of this new method are reduction of additional sodium, following variation of Ca concentration of solution, and omission of dissolving process of a dry chemical. We developed the technique for monitoring Ca removal treatment to automate this method in this study. We detected high correlation between IC of solution and time required for downswing phase of pH DOWN TIME). This suggests realization of automated CO2 aeration method by using DOWN TIME as a monitoring marker.

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