Total reflection X-ray fluorescence spectrometry (TXRF) was applied to the analysis of Pb in an elution test (Japanese leaching test No.13) of municipal solid waste incineration (MSWI) fly ash. A solid phase extraction method (SPE) with chelating resin was combined as a pretreatment for TXRF to remove the deposition of salts in spots of drying eluate on the specimen plate. After treatment by SPE, the accumulation of salt in drying spots on the silica glass plate was decreased significantly. In comparison with Ga internal standard of the TXRF spectra of the drying spots before SPE treatment, the X-ray intensities of matrix components such as K, Ca, Cl, Br and so on decreased to almost 1/100 after SPE treatment. The relative standard deviation (n_mls003d5) of the intensity ratio of Pb to Ga as an internal standard element was decreased from 20.7% to 2.2%. The detection limit was reduced from 0.07mg L⁻¹ to 0.007mg L⁻¹, showing that the detection sensitivity was improved about 10 times. The combination of SPE and TXRF is a rapid, simple, and precise method for the determination of Pb in eluate from MSWI fly ash.

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In the thermal treatment of waste contaminated with radioactive cesium (Cs), Cs compounds are concentrated in fly ash. Hence, the Cs in the fly ash must be immobilized. In this study, thermal changes of kaolin reagents and the properties of dissolution to alkaline solution were investigated. Then, a model fly ash containing Cs was produced in a high-temperature thermal treatment plant to evaluate the immobilization of Cs. Using the calcined aluminosilicates and the model fly ash, geopolymer solidification of Cs was conducted. As a result, metakaolin was easy to dissolve in alkaline solution compared to calcined pyrophyllite, and the Cs leaching ratio from the solidified material with metakaolin was low. It was challenging to evaluate the influences of the aluminosilicates and alkali concentration in the solution on the Cs immobilization only by the composition ratios of solidified materials such as Si/Al. However, using Si_dissolved/Al_dissolved, the balance of Al and Si that directly contributed to Cs immobilization became clear. The dissolution properties of aluminosilicates to alkaline solution were an important factor for the control of Cs immobilization.

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In order to understand trends surrounding the use and disposal of televisions in Japan, we have analyzed the impact of a major shift from CRT TVs to flat-screen TVs taking into consideration digitalization of TV broadcasting. Two models were compared: the lifespan distributions for CRT and flat-screen TVs were the same in the first model and lifespan distribution differed by type in the other model. Compared to the former model, results showed that the latter model better reflects recent trends with regard to units being used. In the latter model, as calculated under Weibull distribution, the average lifespans from shipment to disposal differ between CRT TVs at 12.8 years and flat-screen TVs at 15.1 years. Based on the fact that flat-screen TVs, which have become widespread in recent years, have a longer lifespan than CRT TVs, it may indicate that the overall lifespan of TVs has increased with this shift.

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In this study, a drying experiment was conducted on inorganic sludge with a resin-based drying accelerator in order to clarify the effect of resin emulsion addition on drying behavior. In the experiment, 0.8wt% of acrylic resin emulsion was added to inorganic sludge, and the effect of its addition on drying and the effects of drying conditions such as drying temperature and sludge size on the drying rate were evaluated. Although the drying acceleration effect of sludge differs depending on the drying accelerator type, it was possible to accelerate inorganic sludge drying by adding a small amount of resin emulsion. In particular, the addition of acrylic resin emulsion (DA10) showed a high drying acceleration effect in the large spherical sample with a small specific surface area, since DA10 suppresses the decrease of the water transfer rate inside the sludge. On the other hand, the addition of the drying accelerator to the sludge suppresses the evaporation rate of water on the surface of the sludge, so that it was necessary to optimize the drying temperature and the sludge sample shape when adding the resin emulsion to inorganic sludge.

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In this research, the emission reduction effects of PCB countermeasures in Japan were estimated. It was estimated that the cumulative emission reduction of waste storage from 1950 to 2050 was 65.9tons and the cumulative emission reduction by waste destruction was 65.6tons. Additional waste treatment was estimated to have 3 to 23tons emission reduction. Waste decomposition, which reduces PCB stock, reduces not only immediate emissions but also future emission risks. On the other hand, there are some possibilities that waste storage cannot reduce long-term emissions because PCB stock is kept. Moreover, it was suggested that there are some risks that future emissions would increase in the case of long-term waste storage. It was estimated that the increased rate of PCB waste loss would cause approximately 60 to 110tons increase in cumulative emissions. In conclusion, it was suggested that PCB waste storage has a temporary emission reduction effect, but it is essential to destroy PCB waste in order to reduce future emission risks.

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This study aims to clarify factors that lead people to dispose of disaster waste from cleanup activities after homes were damaged (hereafter termed cleanup waste) at places other than designated temporary storage sites (TSS). Even when local government policy basically advises these wastes to be disposed of at TSS, they are found being discarded at curbsides and other open spaces. We studied actual disposal behaviors and potential determinants of Kurashiki City disaster victims following the flooding disaster of July 2018. The results of a questionnaire survey and its statistical analysis suggest that citizens tend to dispose of cleanup waste at places other than TSS. This happens for several reasons: the TSS is too far away; access to vehicles for transportation is scarce; public information on where to dispose of cleanup waste is not properly understood. Based on these results, we present recommendations for preparedness action, such as identifying open lands that can be modified as TSS in disaster-prone areas.

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The number of leachate treatment facilities with desalination treatment is increasing. When desalination is performed, concentrated solution and dried salt (byproduct salt), which is obtained by evaporating and solidifying the concentrated solution, are produced together with the desalinated water. In recent years, some byproduct salt has been recycled as antifreeze agents, and some has been used as disinfectants at terminal treatment plants by generating NaClO through electrolysis. However, there are many areas that do not use antifreeze agents and nearby areas that do not use disinfectants. Using bipolar electrodialysis (BPED) as one of the recycling methods, a development study was conducted assuming that acids and alkalis are generated and used as a neutralizing agent. Currently, BPED is used in the food and medical fields as a method for producing organic acids and alkalis from organic salts and acids and alkalis from inorganic salts. In this study, we conducted a basic study with different generation sources (leachates from general waste and industrial waste) and different discharge types (concentrated solution and dried salt) of byproduct salt. As a result, HCl with a concentration of 2.82mol/L to 4.23mol/L and NaOH with a concentration of 1.43mol/L to 3.04mol/L were produced.

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After studying demolished buildings and disaster waste quantities, we then estimated generation intensities in order to improve the accuracy of estimating disaster waste. Real data for the amount of segregated disaster waste debris from the 2016 Kumamoto Earthquake was recorded by Mashiki Municipality. We used this to sort the amount of debris derived from the demolished buildings. In addition, a building database was created that associated the existing identification, structure, number of floors, and total floor area of all buildings in Mashiki Town. Based on the relational expression between the total floor area of the demolished building and the actual debris amount data, the basic unit of disaster waste from the demolished building was estimated per total floor area by structure and composition. Findings showed that about 90% of the demolished buildings in Mashiki Town were wooden: the generation intensities were 0.57 (ton/m²) for wooden buildings with tiled roofs and 0.51 (ton/m²) for wooden buildings without tiled roofs. The basic unit estimation value and number of demolished buildings in this study were applied to the estimation formula for five neighbouring towns near Mashiki. We could assess the applicability of our study in the event of a future earthquake based on the fact that our estimated values were close to the actual data.

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A survey comparing processing costs, CO₂ emissions, and life of landfill sites between the currently used mixed collection/landfill treatment method and the newer treatment method that uses composting and carbonization was conducted on the waste being discharged from urban areas and suburbs of Guangnan in Yunnan Province in The People’s Republic of China. Survey results estimate that costs will tend to increase when municipal waste is collected then separated, then newly treated, related to an extended landfill life. Treatment costs were estimated to be reduced and landfill life was extended in the scenario whereby urban waste was separated at home/on-site, then collected and transported using new electric vehicles, and finally newly treated, while suburban wastes were directly landfilled, as is the current treatment method. On the other hand, estimates show that if both urban and suburban waste are separated at home/on-site, then collected and transported by a new electric vehicle, and finally subject to new treatment, costs tend to increase slightly but landfill life is markedly extended. The study also estimates that final CO₂ emissions decreased as a result of reducing the amount of organic waste to be landfilled.

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In recent years, the creation of a recycling-based society has become necessary. The aim of this study was to investigate relationships between the properties of construction sludge and humic substances contained in it. Significant correlations were confirmed between the ignition loss and pH of construction sludge and the content of humic acid. Moreover, significant correlations were observed between the pH and ignition loss of construction sludge, and between the pH and oxidation-reduction potential. This suggests that the values of ignition loss and pH are suitable parameters for estimating the content of humic acid in construction sludge. Through the application of a hydrothermal process to the construction sludge, fluvic acid was extracted selectively in measurements using a three dimensional-excitation and emission matrix. Analysis of the elemental composition showed there was a correlation between the construction sludge nitrogen content and humic acid.

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The objective of this study was to reveal the relationship between the individual sense of ownership among municipal officials in local governments and the efficacy of disaster waste management as an organization. This was done by conducting a questionnaire survey on individual ownership and efficacy assessment for the municipal governments in the Nankai Trough Earthquake disaster prevention area. The results of this relational analysis indicated that the efficacy of disaster waste management tends to be high in the basic municipalities, where the officials have a high sense of ownership. With regard to the Incident Command System framework, it was shown that even municipal officials whose governments had formulated a disaster waste management plan would find it difficult to improve the efficacy of disaster waste management if they exhibited a low sense of ownership. In other words, even beyond formulating a disaster waste management plan, the survey indicated that continuous efforts would be needed to foster a sense of ownership among municipal officials through human resource development for greater efficacy. This paper examines the importance of this sense of ownership in improving the efficacy of disaster waste management and confirms a qualitative and quantitative analysis of the connection.

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Local governments throughout Japan carry out various programs to raise awareness about waste reduction. However, there is no comprehensive information base about what types of residential interventions are available or about what are the effects of waste reduction in households. In this study, five cities ranging from the highest and other five ranging from lowest unit levels of household solid waste emission were selected based on similar population size. Text contents on the municipal waste treatment plans and official website were analyzed quantitatively in order to test whether the various programs could be classified objectively. The official website, which had more extracted words than the municipal waste treatment plans, were considered suitable for analysis of text characteristics. Analysis results for the 78 programs on the official website indicate that these programs can be classified into 14 major types, plus a separate three types that are notably unique. These categories could be interpreted as having different intervention types from each other. It also shows that local governments with less waste have a greater number of programs with more variety, while those with more waste tend to lean toward one-way, mainly information-providing type programs. Expansion of this style of study on many of the official websites of local governments could bring about new information regarding a wide range of programs that aim to raise public awareness in Japan.

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In this study, the water moisture adsorption isotherms of ceramic siding waste powder samples heated at 650, 700, 800, 900 and 1000°C were measured to evaluate hydroscopic property changes resulting from heat treatment. The amount of adsorbed moisture decreased as the heat treatment temperature was raised because the organic material in the ceramic siding waste powder was removed and the specific surface area and pore volume were decreased by heat treatment. In addition, the amount of adsorbed moisture on the ceramic siding waste powder heated at 650, 700 and 800°C was increased by dry and wet cycle treatment, though specific surface area, gel pore and capillary pore volume were decreased. From this result, it was conjectured that micro pores such as intraglobular pores in calcium silicate hydrate (CSH) were formed by dry and wet cycle treatment of these heated ceramic siding waste powder samples. In contrast, the amounts of adsorbed moisture on ceramic siding waste powder heated at 900 and 1000°C changed little. Therefore, ceramic siding waste powder could be used for applications requiring low hygroscopicity by heating it over 900°C.

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Two observational surveys on the behavior of convenience store shoppers in Sapporo were conducted to investigate the effects of a charging system for plastic bags provided at registers implemented in July 2020. Specifically, Survey 1 aimed to examine: S1-1) How did behaviors change after the implementation of the charging system? and S1-2) Was there a difference in the refusal rates for plastic bags between the shops with the charging system and those without? Meanwhile, Survey 2 focused on S2). Could characteristics of those buying plastic bags after the charging system was implemented be identified? Study 1 was conducted from June through August 2020 and 554 samples were obtained, revealing a substantial difference in the refusal rates for plastic bags between the shops implementing a charging system and those without one. Study 2 was conducted in September 2020. The 4289 samples obtained revealed purchasing pattern characteristics related to plastic bag refusal rates: a) The number of people who brought reusable shopping bags was low overall; b) The refusal rate was lower for shoppers who bought bento (box lunch) or packed bowls/dishes than for those who bought other products; and c) The refusal rate was lower when the clerks asked whether a plastic bag was required or not.

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The BDF (Biodiesel fuel) Conversion Project utilizes waste cooking oil for that has been collected from households and businesses for biodiesel fuel in Iizuka City, Japan. The BDF Project has consistently been managed by employment support facilities for people with disabilities through a collaborative project with the Iizuka City office that is not only raising awareness among residents but also purchasing the BDF. When considering the feasibility of recycling, while it is important to ensure economic efficiency it is also necessary to consider the social benefits of implementing the project through a public organization.
　Therefore, both the economic benefits and the social cost benefits of this BDF project were analyzed in this study. Results actually showed the net benefits “related to recycling” showed a negative value, which suggests that “other external benefits” had to be greatly contributing to the continuation of this project. The analysis also gleaned that the external benefits were enhanced by the unique collaboration that took place between the employment welfare facilities for people with disabilities and the local government and other establishments.

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