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The leaching behavior of zinc, lead, and copper from fly ash generated in gasification and melting furnaces for municipal solid wastes(MSW) was studied by a constant pH leaching method with organic acids. The leaching degrees of the above-mentioned heavy metals were as low as 10%, or lower at pH 2 for the residue, obtained by leaching fly ash with water. The leaching degree of heavy metals increased remarkably by adding organic acids. The leaching degrees of zinc, lead, and copper were 64, 64 and 91%, respectively, under conditions where the concentration of citrate was as low as 0.001M, and pH was 4. The reason why citrate is effective in the leaching of heavy metals may be due to the catalytic acceleration action of dissolution, but not the stabilization effect for heavy metals in solution. The degree of leaching for zinc, lead, copper, and silicate decreased by elevating the reaction temperature from 278K to 323K. A constant pH leaching method with citrate has features such that high leaching degrees for heavy metals are obtained, and silicate gel, which is difficult to be filtered, is not generated.

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Melt-and-solidify process is one of disposal method of illegal dumped industrial waste in border area of Iwate and Aomori prefectures. However, the processing and the application of the molten slag that occur voluminously are turning social problem. There were hardly investigated utilize molten slag from illegal dumped wastes to aggregate for concrete. The concrete blended with molten slag, produced from illegal dumped wastes by commercial surface melting furnace were tested. These analysis tests showed that there was no chemical harmful metal ions in solution from the molten slag. And concrete product, produce of low 30% molten slag replacement ratio to fine aggregate had no problem with strength and freeze-thaw resistance.

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The cold filter plugging points (CFPP) of bio diesel fuels (BDF) derived from animal and vegetable fats were analyzed. Animal fats, including a large amount of saturated fatty acids, showed high CFPP.These data were in agreement with values calculated by solid-liquid equilibrium assuming that C16Me and C18Me were solid components. It was suggested that decreasing the amount of C16Me and C18Me to 10wt% or less by crystallization process and others improves CFPP that meets the BDF standards.

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The reaction conditions on the pyrolytic liquefaction of organic matter in the mixed waste were discussed in this paper. The reactions were carried out at a desired temperature (553K, 573K, 623K, 673K) for a desired time (0min, 60min) with an atmospheric initial pressure by using a semi-batch reactor. However, the reaction at 673K was carried out for 60min only. For a comparison of the product yields by the difference of reactor type, the reactions were also carried out at a desired temperature (573K, 623K) for a desired time (0min, 60min) with an atmospheric initial pressure by using a batch reactor. As a result, it was clarified that 59% of organic matter in the mixed waste was converted into the oil constituent (hexane soluble) on the reaction at 623K for 60min by using a semi-batch reactor.

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Pavement materials for snow melting composed of two layers; one of which is mixed with charcoal for insulation and the other was mixed with graphite for heat transfer , was made. Practice examination using artificial weather chambers and outdoor demonstration one was conducted and the results of good capability for snow melting were obtained.

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Biomass is reusable resources for reducing CO2 concentration. Sub-critical and Supercritical water (SCW : Tc=374oC, Pc=22.1MPa) is an interesting medium which is able to convert these biomass into chemical resources without the use of catalysts. From recent works, it was found that valuable organic compounds could be obtained within short reaction time and high yield could be achieved by manipulating reaction temperature and pressure to control reaction rates and equilibria. In this work, experiments were carried out by using novel continuous reactor. When D-fructose is used as a model substance of biomass, it was suggested that 5-HMF and Dehydroxyacetone and Glyceraldehyde were obtained high yield.

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An attempt to decompose odour compounds including oil mist or very small carbon particles was made by using plasma discharge. In order to evaluate decomposition efficiency, the proof run was carried out.

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A new type of corrosion sensor was produced experimentally for continuous monitoring of the high temperature corrosion of boiler superheater tubes in waste incinerators, and the field test was twice carried out to establish the corrosion monitoring system. In the test, the corrosion rate of a boiler tubing alloy was measured at 30-minute interval, and the state of measurement was monitored by wireless communication equipment. The value of the corrosion depth estimated by numerical integration of the corrosion rate measured with the sensor agreed well with those measured with micrometers. The observed data provides a contour map of the corrosion rate, which is useful for the structural design and material selection for waste incineration boilers.

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This paper studies the fundamental formation characteristics of fine particulates during the wasted oil combustion. The combustion experiments are conducted, using a drop tube furnace with a spray burner of two-phase flow type. The particulate matter in the exhausted gas is collected and classified by a Low Pressure Impactor (LPI) isokinetically. This study focuses on effect of content of residual carbon and Polycyclic Aromatic Hydrocarbons (PAH) in a fuel on the PM formation. The light oil with C-type heavy oil or several types of aromatic hydrocarbons are tested as the simulated waste oils. As a result, particle size distribution of the particulates during light oil combustion at stoichiometric air ratio of 0.8 becomes single-mode with the size between 0.08 and 0.24 mm. The PM collected looks like a tar as precursor of soot particles. The residual carbon and aromatic hydrocarbons in a fuel affect concentration of precursor of soot particles and formation of submicron particles with size between 0.08 and 0.24 mm. Additionally, 3 to 4 rings PAHs are concentrated in the precursor of soot particles.

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The authors carried out some kinds of analysis on carbon products which was produced with superheated steam pyrolysis (SHS) comparing with traditional batch methods. Bagasse (sugarcane squeezed residue), cattle and poultry excrements were used as source materials. We mainly obtained the following results; 1) Chloride content of the carbon products which was produced with SHS are larger than those of the traditional batch method. And average pore size with SHS is generally smaller than those with the batch methods, 2) There is not a significant trend on potassium content of the carbon products between the methods, 3) Difference among the source materials are more significant.

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The purpose of this study is to establish recycling technology of waste phenolic resin to be most suitable for an area. The carbonization and activation behavior of waste phenolic resin was examined to make a functional adsorbent material. The activation behavior of the was waste phenolic resin improved by the addition of calcium hydroxide. The waste phenolic resin with calcium hydroxide after carbonization and activation showed high adsorption of phosphate ion. As a result, it is expected that the adsorbent material made from waste phenolic resin has two functions of pore adsorption and phosphate ion absorption.

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We have developed a new exhaust-gas treatment system using ceramic filters and a sodium reactant that removes particulates and acid gases in the temperature range of 300 degree centigrade. This system has been applied to a kiln-type pyrolysis gas melting plant for MSW (70t/24h, 2 units). As the heat source for the pyrolysis, the exhaust from burning the combustible gas generated by the pyrolysis process is used in this plant. This new filtration system has been applied to this exhaust gas at the temperature range of 300 degree centigrade for the removal of acid gases and the particulates. The dust-collection efficiency of the ceramic filter has been better than 99.8% with the pressure loss of roughly 2.2kPa at the filtration speed of 1.5m/min. To prevent the corrosion of the heating pipes that carry the combustion exhaust, the HCl concentration after the exhaust treatment was set at 15ppm by controlling the reagent feed rate, enabling a stable operation within the corrosion-free state.

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