Due to the heavy rain that hit West Japan in July 2018, a large-scale flood occurred in Maki-machi, Kurashiki city due to the river collapse on the 7th, and the heavy rain that hit West Japan in July resulted in 7 in Mabi-cho, Kurashiki-shi. Large-scale floods occurred daily due to river collapse, resulting in approximately 440,000 tons of flood damage. When the house cleaning starts, they are discharged all at once in the area, which causes a shortage of storage space and waiting for garbage collection. In Mabi-cho, there is an illegal discharge site where citizens can bring in garbage by car under the elevated road construction site along National Route 486 and under the Ihara Railway Ihara Line, and the Self-Defense Forces will remove it. In order to control the discharge of clean-up trash immediately after the occurrence of a disaster and to make a plan to collect it quickly, it is effective to first analyze the clean-up trash discharge behavior actually taken by the victims. Therefore, in this study, we conducted a questionnaire survey on the victims of Mabi-machi, Kurashiki city, and analyzed the recognition of discharge rules, the possibility of separation, the place of waste discharge, and the reason why they were dumped at illegal discharge sites.

Due to the heavy rain that hit western Japan in July 2018, a large-scale flood occurred in Manabi-cho, Kurashiki city on the 7th, which caused about 440,000 tons of flooded waste. When the cleaning of houses starts after the disaster, they are discharged all at once in the area, which causes a shortage of storage space and waiting for garbage collection. In previous research 1), it was found that if the collection of waste is delayed, the storage space becomes full, which causes illegal discharge. In the event of a disaster, it is necessary to smoothly collect and remove disaster waste from the disaster area, and for that purpose, it is important to first understand the characteristics of the waste discharge time of clean-up waste. In this study, we conducted a questionnaire survey on the victims of Mabi-machi, Kurashiki City, clarified the emission characteristics and emission timing of each type of cleanup waste, and created an emission model. Then, for the waste discharge from the target area, a collection strategy was established and a collection simulation was conducted.

Night soil ocean dumpimg was started from 1935 and Tokyo metropolitan government was doing way with Night soil ocean dumpimg by 1999.

This report shows the histry.

A Ward-Based Approach (WBA) was introduced in both Dhaka, Bangladesh and Khartoum, Sudan as an administrative system for urban solid waste management in large cities. This is a comparative case study on the process of how a WBA was established in both cities and aims to evaluate the applicability of a WBA in other cities, and to clarify the conditions for success. Results show a WBA can be applicable for large cities in general, regardless of the diversity of the region, culture, social situation, waste collection system and waste management bodies in the city. Commo key factors for success are i) the population volume of each ward (around 7-10 thousand), ii) a core group formed for waste management in municipalities, prior to the official establishment of the waste management department, and a master plan or upper plan of solid waste management stipulating the introduction of a WBA in its initial phase, iii) the construction of waste management offices in each ward as a center of waste management at field level, and iv) the existence of key persons as a change maker to promote a WBA strongly as a mainstream system in municipalities. Key persons can be either high-level officials or field workers. Further research is required to figure out the mechanism of how to motivate key persons and how to get them exited about a WBA.

Various types of industrial waste are used in the cement industry. In particular, the alternative energy resources used in cement burning include automobile shredder residues and other plastic waste that are difficult to materially or chemically recycle. In general, such plastic waste is incinerated without energy recovery and/or disposed of in landfills, but it is effectively used as an energy source in cement production.

This study aimed to determine the effect of using plastic waste in cement production on the reduction of CO₂ emissions applying the life cycle assessment method. CO₂ emissions were compared between the following two systems: (1) the recovery system to use plastic waste substituted for coal and (2) the conventional system to use coal and dispose of plastic waste by simple incineration in landfills. The system boundary was defined to cover the disposal of plastic waste, pretreatment of plastic waste, transport of raw materials and residues, and the production of required energy in addition to cement production.

Results indicated that using 23 kg of plastic waste per ton of cement resulted in a reduction in coal use by 29 kg. This led to a reduction of 75 kg in CO₂ emissions per ton of cement produced.

Efforts for resource recycling and recycling of plastic containers and packaging and products are progressing. There is also growing interest in efforts to collect and recycle plastic containers and packaging, which have been promoted under the Container and Packaging Recycling Law up to now, and other plastic products. The government will start policy study based on the plastic resource recycling strategy from May 2020, and plans to show the basic direction this summer. With this as an opportunity, technological innovation will progress and effective and efficient recycling systems will be created. This paper describes future plastic resource recycling/recycling, construction of recycling chain, and combination of recycling technology.

Brominated flame retardants are used in various products such as electrical products and electronic devices because of their efficiency and convenience. Among these, polybrominated diphenyl ether is subject to international regulation under the Stockholm Convention on Persistent Organic Pollutants(POPs). In this study, it was estimated this abundance by analyzing the bromine content contained in the waste of home appliances. This analysis was conducted when the brominated flame retardant was continuously used with and without regulation. Upon analyzing the bromine content from each scenario, differences due to the presence or absence of the regulations were clearly evident.

Brominated flame retardant especially DecaBDE that have been used as retardant in interior of vehicle body become a subject of discussion when plastic from ASR is used as a recycle plastic material because of its toxicity. This report is about locality, amount, form of bromine in plastic from ASR, and sorting and remove method. Plastics, separated from ASR included not only plastic but also foreign materials such as urethane, and bromine detected mostly in urethane. Some plastic pieces also detected DecaBDE, but the concentration was quite low after surface polishing to remove attached impurities. The main source of DecaBDE from ASR is considered in urethanes attached to plastic. The regulated concentration of brominated flame retardants for recycle plastics is still under debate, but plastic from ASR can be a recycle plastic material with low level of DecaBDE by suppression of mixing of urethane.

The number of electric vehicles are increasing because of various automobile environmental regulations in each country. This causes a rapid growth in traction Lithium-ion battery (LiB) applications. However, recycling system of traction LiBs has yet to be fully established. Since a large amount of rare earth elements are used in traction LiBs, the effective use of spent traction LiBs is of significant importance. This study estimates the amount of resource use during the stage of reuse, recycling, and repurposing (for a stationary household battery) of spent traction LiBs by applying the concept of total material requirement. Then, the entire life cycle of a traction LiB is modeled by using system dynamics. Through the model simulation, the effect of reuse, repurpose and recycling on the reduction of primary resource is analyzed and, by changing the selection criteria of spent traction LiBs, the optimal resource use in the entire life cycle of traction LiBs is evaluated.

This study clarify used motorcycles recycling network is constructed between the companies in Vietnam.

The contributions of this research study are twofold. The first, there are import distributors, used parts distributors, used car distributors, repair companies, and miscellaneous goods companies in urban areas. The second, in rural areas, there are companies that repair, sell used cars (rebuilt), and sell used parts.

We are conducting research on recycling of used End of life Vehicle glass. We have developed a device for collecting glass from window glass of End of life Vehicles. In this paper, report on development on products using window grass. In the survey, the possibility of substituting raw materials for Okinawa aka kawara and Ryukyu glass was investigated. Result, it is cleared possibility as a raw material substitute.

The fluorine content in a Lithium-Ion Battery (LIB) and the fluorine fixation reaction with calcium carbonate were examined for the purpose of safe treatment of fluorine-containing gas generated by calcination of spent LIBs. In the water leaching experiment of LIB components, the amount of leached fluorine was measured using a F^- selective electrode, and it was found that water-insoluble fluorine was converted to soluble species by heat treatment. Moreover, it was shown that the cathode material contained more fluorine than the anode material by the repetitive leaching. In order to fix HF generated by thermal decomposition of PVDF used as the binder resin for the cathode material of LIBs, a fluorine fixation experiment with calcium carbonate was conducted. As for the influence of the reaction temperature, it was found that calcium fluoride was formed avobe 400 ℃ under inert atmosphere. A quantitative analysis of XRD data employing internal standard method revealed that the maximum fluorine fixation ratio of 99 % was achieved.

In this research, we focus on the material recycling process of used automobile window glass. Site improvement was carried out using material flow cost accounting (MFCA).As a result of the test, the cost of waste treatment due to glass loss was particularly high among the negative products, so the material recycleing process was improved. As a result, in terms of waste costs, glass loss decreased by 48.8 points from 71.8% to 23.0%. MFCA data also clarified new challenges. It suggested that MFCA is a method that leads to continuous improvement.

Most of ceramic siding is disposed as industrial waste because the weight ratio of organic mixture in ceramic siding is higher than that in concrete and mortar. On the other hand, drying shrincage crack of cement material often becomes problem under repeated drying-wetting conditions. To prevent the drying shrincage crack, water content in cement material is decreased by mixing aggregate. Then, hygroscopicity of aggregate is desirably low. In this study, water vapor adosorption on ceramic siding treated at various temperature was investgated to develop the low hygroscopic aggregate. As a result, the amount of water adsorption was decreased by treating at higher temperature. This result suggested that the decrease of water vapor adsorption amount was caused by the decrease of specific surface area, pore volume and surface hidrophilicity.

In recent years, because of generation of hydrogen sulfide, waste gypsum board has to be disposed of in controlled landfill sites and the burden of disposal costs has increased. In this study, the waste gypsum board generated from the demolition sites was solidified with cement together with the waste glasses, and the strength and hydrogen sulfide generation potential of the specimen solidified with cement were measured. The uniaxial compressive strength of the specimen prepared under the conditions of 30% cement, 35% waste gypsum, 35% waste glass and 0.33 water content was 13.4 N/mm2. Total organic carbon (TOC) concentration leached from the waste gypsum board-adhered paper was 266 mg/L. However the TOC concentration from the solidified specimen was 21 mg/L and hydrogen sulfide gas was not detected. It was indicated that the removal of paper attached waste gypsum board is important to recycle waste gypsum.

Gypsum board wastes containing arsenic exist in some areas of eastern Japan.

We evaluated a test method by using hand-held XRF, to promptly detect arsenic-containing gypsum board waste when it is dismantled or accepted at an intermediate treatment facility.

The measurement accuracy of the hand-held XRF was confirmed to be sufficient.

It was found that the criteria (leaching concentration) for landfills was satisfied when the arsenic content was less than 150 ppm.

In this study, we constructed estimating equations on “true water content w_t” and “apparent water content w_a” obtained by JIS method of stabilized soils using reclaimed hemihydrate gypsum, based on chemical equation. As the estimating equations, it was possible to estimate “true water content w_t” and “apparent water content w_a”. And by the estimating equations, it was possible to check the difference between “true water content w_t” and “apparent water content w_a” obtained by JIS method. Furthermore, when we calculated geotechnical information by using “true water content w_t” of stabilized soils by reclaimed hemihydrate gypsums, it was possible to estimate accurately geotechnical information such as dry density, void ratio, degree of saturation, and so on.

We propose to extract humic acid from construction sludge and utilize it effectively for biomass resource production in order to find an effective recycling method of construction sludge discharged from the construction site. Humic acid was extracted from construction sludge discharged from 5 different construction sites. The properties of the obtained humic acid were evaluated by three-dimensional fluorescence measurement and metal analysis. As a result, it was suggested that the influence on biomass production greatly differs depending on the quantity and quality of humic substances contained in construction sludge.

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A large amount of chlorine remains in the incineration residue. Therefore, the chloride ion (Cl-) concentration in leachate is increasing at the final disposal site, and the number of facilities introducing desalination equipment for leachate treatment is increasing.When desalting treatment is performed, by-product salt is generated, and treatment of by-product salt becomes an issue.Using bipolar membrane electrodialysis equipment, which is one of the recycling methods of by-product salts, we conduct research to generate acids and alkalis and recycle them as neutralization, etc. We report that we conducted an experiment to improve the recycling value (improvement of concentration).

The purpose of this study was to clarify the effects of mixing intensity on the quality of treated water and the recovery of fertilizers when N, P, and K were simultaneously recovered from swine wastewater at high pH using a batch recovery system. Experiments were performed using a batch reactor. The sedimentation velocity was almost constant when the between of 20 to 70 sec^-1, but the sedimentation velocity decreased at the mixing intensity over 70 sec^-1. The SS concentration was as small as 120 mg/L at the maximum, and the solid-liquid separation was sufficient. At a mixing intensity of 31 sec ^-1 or less, the total concentrations of P and N in the treated water satisfied the drainage standards. The recovery rate of N as fertilizer increased but recovery rate of K as fertilizer decreased with increasing mixing intensity. The average recovery of the sum of N and K was maximum (92%) at a mixing intensity of 31 sec^-1. The recovery rate of P as fertilizer was 100% regardless of the mixing intensity. From the viewpoints of both water treatment and resource recovery, the optimum mixing intensity was 31 sec^-1.

Metallic resorce recovery from waste thermal treatment processes is drawing attention, and on the precious metals such as gold, several recovery methods such as using sieving of ash or adjusting the thermal treatment conditions have been reported. For further developments, it will be useful to understand the fundamental behaviors of target elements in various conditions and atmospheres. Possible chemical forms of gold during waste thermal treatments are elemental gold or alloy, sulfides, halides, and those dissolved in the molten aluminosilicate stags. It is not much understood how the treatment conditions or gas phase atmospheres affect the vaporization behavior of gold during the waste thermal treatments. In this study, we examined the vaporization behaviors of gold at high temperatures using thermodynamic equilibrium calculation assuming waste thermal treatment conditions.

Phosphorus recovery from dehydrated waste water sludge by incineration using alkali metal compounds was carried out. The dehydrated sludge was mixed with NaOH, KOH or Na₂CO₃, and incinerated at 750 degree to 900 degree after drying treatment. Phosphorus was recovered by extraction using water. The phosphorus was recovered as a form of alkali metal phosphate, and recovery rate reached about 75%.