The excess moisture contained in organic resources, including biomass, sewage sludge and garbage, reduces the efficiency of thermal chemical transfer, and interferes with the effective use of these resources in waste treatment systems. However, effective use of waste heat from plants makes it possible to dehydrate these resources.
As a means to solve this problem, this paper describes the specific requirements of the drying process in terms of the drying method and the heating temperature. We have studied the following two drying methods : direct heating by hot gas, and indirect heating by steam.
The drying process requires efficient use of exhaust heat generated in the system. In addition, the emission of harmless gases during the heating process, instead of hazardous gases such as dioxin, is also required. We installed and tested an indirect heat dryer at a demonstration plant featuring a thermochemical conversion (pyrolysis gas reforming and gasification) system for treating municipal solid waste at 10 ton/d. As a result of the test, the high drying performance and the superior harmlessness of the emitted gas was verified and the system was proven to be an excellent waste treatment method.

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Bamboo charcoal was carbonized at 500 °C in an N₂ gas flow for 2 hours with a heating rate of 25 °C/min. Subsequently, the bamboo charcoal was oxidized in air for 2 hours at 180, 280 and 380 °C. The surface areas and the pore volumes were measured with BET, α_s-plot and t-plot methods, and surface functional groups were determined using Boehm titration. The surface area of the bamboo charcoal was increased by the air oxidation. The surface areas expanded from 250m²/g for the original to 340m²/g at 180 °C and 680m²/g at 380 °C. The pore volumes were also increased from 0.16mL/g to 0.31mL/g by air oxidation at 380 °C. Moreover, both surface areas and pore volumes were increased a little by outgassing at 1000 °C. In addition, the amount of surface functional groups on the bamboo charcoal was increased by the air oxidation. In particular, carboxyl groups increased significantly from 0.02mmol/L in the original to 1.19mmol/L in the 380 °C sample. These results suggest that air oxidation following low temperature carbonization is possible to prepare bamboo activated charcoal with abundant surface functional groups as well as greater surface area and pore volume.

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To develop a new agent for immobilization of lead form fly ash, AlPO₄ was synthesized from a phosphorus-rich solution from chicken manure incineration ash and Al(OH)₃ solution as aluminum effluent. The ability of synthesized AlPO₄ to immobilize lead from fly ash was evaluated. The synthesized AlPO₄, with high rates of filtration and phosphorus recovery, could be obtained at the L/S of 5 and a pH of less than 1 for extraction of phosphorus solution from the chicken manure incineration ash with sulfuric acid and at the pH of 5 for synthesis using Al(OH)₃ solution. The result of JLT 13 showed that the synthesized AlPO₄ had the same high lead immobilization ability as that of commercial AlPO₄ on the basis of added phosphorus to the ash. In addition, from result of availability test on pH4 suggested that aluminum phosphate has a high lead immobilization ability under acid condition. Amorphous aluminum phosphate is an effective immobilization agent for heavy metal such as lead in scrubber residues.

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Volatilization behaviors of lead compounds from CaO-SiO₂-Al₂O₃ were studied using a lab-scale heating apparatus under N₂-HCl mixed gas flow rate of 5×10⁻⁶m³ · s⁻¹ (gas velocity of 3.61×10⁻³m · s⁻¹) at HCl partial pressure of 0.0017, 0.005 and 0.0067 atm in the temperature range of 1673 to 1773K. The employed slag samples were adjusted to 20-40wt% CaO, 30-60wt% SiO₂ and 20-40wt% Al₂O₃ in composition. The initial content of PbO in the slag samples was set at 2000mg · kg⁻¹. The rate of volatilization of lead compounds from the molten slag was determined by time change of the content of PbO which remained in the slag.
As a result, it was found that the rate of volatilization of lead compounds from CaO-SiO₂-Al₂O₃ molten slag in N₂-HCl atmosphere was higher than that in N₂-O₂ atmosphere. The apparent rate constant of volatilization of lead compounds from the employed slag samples increased almost linearly with the HCl partial pressure. It was also found that the rate of volatilization of lead compounds was higher from CaO-SiO₂-Al₂O₃ molten slag, with a lower viscosity of high CaO content slag, and was higher with a rise in melting temperature.

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Polychlorinated biphenyls (PCBs) are harmful substances for which complete treatment inside Japan is mandated by 2016. For this study, we conducted PCB elution experiments using a high-concentration PCB contaminated capacitor and a high-voltage transformer. Simultaneously, we conducted dechlorination using a microwave-assisted catalytic reaction. The diffusion equation for PCBs in the internal core and the reaction rate equations of the dechlorination reaction for eluted PCBs were solved. Results show that this method can explain, quantitatively, the time change of PCB concentrations measured in these experiments. The calculated concentrations of PCBs accorded well with the measured values for indoor capacitor detoxification tests. Therefore, this simulation is regarded as effective for PCB concentration prediction. However, if the reaction rate constants were not changed for all reaction time zones, then the calculated values did not accord with the measured value in the case of the high-voltage transformer detoxification storehouse test, in which the IPA solution temperature was affected by outside air. The decrease in the reaction rate caused by insufficient KOH resulting from the lower solubility in the lower temperature, and other reasons were regarded as reasons for the disagreement.

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Although aerosol cans and gas cartridge cans are known to cause fire accidents during collection and processing, research relating to these accident situations and measures taken by municipalities has not yet been conducted. Moreover, strategies for improving the situation have still not been properly analyzed. This study is based on a questionnaire that was circulated in 287 cities of more than 100,000 residents. The current situation regarding fire accidents in the municipalities, due to aerosol cans, was analyzed quantitatively and remedial measures were then discussed. 1.5 fire accidents per 100,000 people occurred in collection vehicles, along with 0.7 in shredder facilities in 2009 fiscal year alone. Most of the vehicle fire accidents were generated in the noncombustible waste collection, and fires with aerosol cans accounted for 52.5%. It is preferable to avoid collecting aerosol cans as noncombustible waste. The inappropriate disposal of aerosol cans must be addressed effectively, and necessary measures for preventing the disposal of aerosols in which the contents still remain in the can must be taken up immediately.

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Proximate analysis values, ultimate analysis values, and heating values of solid waste are fundamental characteristics in solid waste management planning. With regard to standard composition analysis in Japan, however, these values are not reliable due to sampling error of the analysis and contamination from mixing waste for sampling. Accurate quality of waste can only be estimated by understanding the detailed composition and characteristic values.
This study focuses on determining characteristics of paper, plastics, and food waste generated from households. To minimize contamination, samples were taken from source-separated mixed paper and plastic containers/packaging at sorting facilities. Food wastes packed in small plastic bags were sampled to minimize moisture drainage. Papers and plastics were sorted into 43 and 36 categories based on shapes, usages, and appearances.
Analyzed values were compared against virgin materials such as cellulose, polyethylene and hydrocarbon to show the origin of each waste component. The origin of chlorine in household waste, as well as the carbon content of plastics, were also estimated as a means for incorporating the data into the field of solid waste management.

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