In order to achieve the recycling society worldwide, it is important to analyze material stock and flow on a global scale and understand their accumulation trends and patterns. World-wide satellite images data is easily and quickly accessible, and it breaks the restriction of statistical data. Recently, Convolutional Neural Network (CNN) is received a lot of attentions as a technique in the analysis of satellite images. Our study made efforts to develop an advanced model for estimating the total floor area of buildings based on night light data using CNN. Three major metropolitans in Japan (Tokyo, Osaka, and Nagoya metropolitan area) were selected as the estimation areas and the learning areas, setting one metropolitan as learning area to estimate the buildings floor areas for the other two. And same procedure has been done three times as each metropolitan was changed to be learning area in turns. Additionally, we verified the accuracy of results to examine the effectiveness of our model. In the case of “Osaka learning for Nagoya estimation”, it was clear that the total floor area of buildings in Nagoya metropolitan area was 450 million m², which is close to the real value and indicates our model can be useful?

 The rainwater harvesting house which had flood control function was constructed in Fukuoka City on April 2014. Under the serious drought condition or large-scale disaster, supply for daily life water is a major problem in JAPAN. In this field study, we suggest the possibility of rainwater harvesting as a sustainable water supply option in highly urbanized areas. From the field observation data on the rainwater harvesting house, rainwater proper management could reduce water and flood crisis in the urbanized areas.

 The Japanese eel, Anguilla japonica, elvers in their upstream migration period averaging 5.8cm total lengths, were examined for their swimming ability in an experimental flume. Our results are as follows: 1) The results of the elvers burst swimming speed were 36-56cm per second (6.4-10.0 body lengths cm/s). 2) It was observed that the elvers could not make progress against water currents greater than 50cm/s on their noses. Even slight advances were difficult. 3) Against less than 39cm/s water current, 68% of the elvers were able to make more than 30cm upstream progress. 4) These results indicated that most of the about 6cm elvers would not be able to ascend many standard stepped-pool type fishways in Japan. Therefore, for elvers to migrate successfully, it is necessary to regulate the water velocity in some places, or provide upstream migration facilities to accommodate the elvers’ climbing behavior. This would be essential at weirs of high flow velocity.

 Japanese eel is now endangered, and there is an emergent need for accumulating ecological knowledge during its riverine life. This study aimed to elucidate the influence of benthic invertebrate abundance (i.e. food availability) on the stock of Japanese eel based on quantitative surveys conducted in two coastal streams in Ehime Prefecture, southwestern Japan. As a result, eel abundance was shown to be high at study sites with high invertebrate abundance. This result suggests that conserving food resource can be an effective option for the conservation of Japanese eel. However, since this relationship differed depending on the rivers and seemed to be confounded with other physical factors, we suggest that extensive survey and analysis is required for disentangling the causal relationships among factors affecting eel stock and for better conservation planning.

 This study focused on fish species to investigate methods for improving the environment of the Amagasaki Canal. Analysis of the food web revealed that a benthic fish species Tridentiger obscurus has an important role in transferring energy from primary producers to organisms at higher trophic levels. The result suggest that protection of the bottom dwelling T. obscurus is effective for improving the environment of the canal by making excessive nutrients ingestible for other organisms. When artificial shelters for T. obscurus was set in the canal, a large amount of mussel Xenostrobus securi attached to the shelter. The result insists that further improvements are needed to prevent clogging by the shells and make shelters available for T. obscurus.

 We developed the method for evaluating reduction effects on ecological risk according to improvement of sewage treatment rate by using AIST-SHANEL Ver. 3.0, and applied it to Gunma prefecture’s sewage treatment plan. LAS and AE, chemicals used for detergent, are targeted for and we prepared SSD (species sensitivity distribution) functions to estimate the values of PAF (potentially affected fraction of species). We set a present scenario and three future scenarios: Present scenario stands for baseline scenario where prefecture-wide sewage treatment rate is 72.2% in FY2015; Scenario A reachs to 76.1% in FY2030 by improving connection rate of sewage line; Scenario B reachs to 89.2% in FY2030 by replacement of private wastewater treatment tank; and Scenario D reachs to 100% in FY2040. River concentrations of LAS and AE were estimated in each scenario and reduction effects on PAF were cleared through comparison between scenarios.

 In this study, we calculated the SROI of the social impact of the environmental improvement activities performed at the Amagasaki Canal. In recent years, the necessity of reliability evaluation of SROI by sensitivity analysis has been discussed. Therefore, in this study, we focused on the range of values that can be taken as the SROI by setting the monetary surrogate index, outcome index (time, number of people, etc.) and contribution rate required for SROI calculation as parameters, and setting multiple can-didates of the parameters from literature value and hearing surveys. As a result, it was calculated that the SROI of the environ-mental improvement efforts of the Amagasaki Canal in FY2017 could range from 0.85 to 3.49. Moreover, as a result of sensitivity analysis, the change in the range of variation of SROI by monetary surrogate index is the most significant for this case.

 In this study, we targeted in a 100, 000 inhabited city, and designed two measures: The first one is integration of sludge treatment function, where septic tank sludge is treated with sewage sludge in a sewage treatment plant (STP); The second one is integration of incineration function, where dewatered sludge is incinerated with Municipal Solid Waste (MSW) in a MSW incineration plant.Direct combustion of dewatered sludge in a MSW incinerator is targeted for, and we developed the energy balance analysis model for estimating varidation of combustion gas temperature. Base case stands for no integration planning, and case B does both two integration measures. Under a system without digestion tank installation in a STP, energy recovery rates were estimated to 14.9% in Base (nonDG) case, and 30.4% in Case B2 (nonDG) where a high-efficiency sludge dewatering equipment is installed in a STP. Under a system with digestion installation, energy recovery rates were estimated to 20.7% in Base (DG) case, and 30.2% in Case B (DG).

 The greenhouse gas (GHG) emission reduction targets in Japan are 26% reduction by FY 2030 compared to the level in FY 2013, and 80% reduction by 2050. It is required to reduce CO₂ emission drastically from energy consumption of households in order to achieve the targets. On the other hand, diffusion of new energy technologies such as residential photovoltaic (PV) systems and battery electric vehicles (BEV) have a great potential to change energy consumption and contribute to CO₂ emission reduction in household sector.

 Many previous studies on Japan’s mid- and long-term CO₂ emission from energy consumption analyzed the roles of residen-tial PV system or BEV outside of residential sector, and the impacts of such technologies on households’ energy consumption are not taken in account. In this study, a new device-selection model is constructed in order to assess the change of whole energy consumption caused by PV system and BEV in household. In addition, by the difference of household attibution such as house-holds living in detached house or apartment house, CO₂ emission from household is estimated, and feasibility of mid- and long-term CO₂ emission reduction targets is assessed.

 The results of model analysis indicate that it is necessary to decrease the CO₂ emission factor of grid electricity in order to achieve the 2050 target, and it is also required to promote electrification by decreasing city gas, kerosene and gasoline consumption. Residential PV system can increase the electrification rate of households and contribute to CO₂ emission reduction. BEV also have great potential to reduce CO₂ emission of households living in detached house with residential PV system at the same level of that in apartment house.This study concludes that PV and BEV play important roles to reduce CO₂ emission in household.

 We constructed a model for estimating the future supply and demand balance of non-metallic mineral recycling resources at the prefectural level until FY2030. Using the model, we evaluated the waste generation control scenario. In the BaU scenario, the results showed that the supply of non-metallic mineral recycling resources exceeded the total demand of non-metallic mineral in 18 prefectures in 2030. In the waste generation control scenario, the result is that the supply-demand balance can be reduced by 11 points on average in Japan.

 The aim of this study was to analyze the power generation and GHG reduction in several energy recovery systems used in municipal waste incineration and sewage treatment plants in Wakayama City. Scenarios were first constructed by combining the energy recovery technology with either the waste incineration plant or sewage treatment plant and then, other scenarios were constructed based on mixing the sludge and waste from both plants followed by incineration or biogasification. The power generation and GHG reduction in these scenarios were calculated based on heat balance analysis. The results indicated that the power generation increased and the GHGs decreased in all scenarios compared with the present system. The scenario involving biogas power generation was the one achieving the highest energy recovery.

 Movement for the introduction of the decentralized energy system mainly on inflection such as the renewable energy accelerates. In this study, quantity of energy demands and the maximum quantity of renewable energy targeting at manufacturing industry in residential / commercial sector and industrial sector of Kitakyushu city were estimated and estimated introduction potential of the renewable energy when a carbon footprint and total cost were minimized. As a result, when it minimized CO₂ emission, ratio of offshore wind power grew big, and it was shown that the grid power occupied the biggest ratio when it minimized total cost.

 In this paper, we created a regression equation to calculate the annual emission per capita for each third-order mesh using individual data of household CO₂ statistics survey by MOEJ. This made it possible to show the current per capita emissions from the use of residential and passenger-car by each third-order mesh. Regression formulas were created separately for residential and passenger-car, and the prediction performance was evaluated based on comparisons with emission estimation models from previous studies, using statistics for each prefecture as verification values. By using the regression equation of the hous-ing created in this study and the model for estimating automobile emissions of Chen et al. (2018), the per capita emissions by mesh, which is highly consistent with the statistics by prefecture, can be obtained. The value obtained by adding the emissions per capita the use of residential and passenger-car has many meshes centered around 3t-CO₂, and the ratio of the passenger-car emission to the added value is 15-65%. The result is consistent with the analysis result of each municipality conducted by Matsuhashi et al. (2018).

 The IPCC in its fifth assessment report on climate change has forecast that global warming will have a major impact on health conditions. Especially, growing proportions of older people are increasingly exposed to risks which are vulnerable to the impacts of climate change. The rise in temperature due to global warming is increasing the number of heat stroke patients transported to hospitals. The purpose of this study is to visualize urban vulnerability to heat disorders. In this study, we define the urban function aggregation(UFA) index consisting of population density, facility density, and accessibility to urban facilities. We performed a correlation analysis between the UFA index and the number of heat stroke transported in the neighborhood, and then it is clarified the classification of neighborhood characteristics by cluster analysis based on the UFA index for Sakai City, Kobe City, and Kyoto City. As a result, the UFA index are strongly correlated with the number of heat stroke transported and then shown that it is an effective index to express the vulnerability of a neighborhood to heat disorders.

 In recent years, the outstanding wind on lake biwa has shifted from the northwest to the north. In this paper, we simulated the transition of lakeshore shape after wind direction change under multiple scenarios using lakeshore energy flux as an index.

 As a result, when the excellent wind approached the north, it was found that the lakeshore energy flux increased near the mouth of the Amano River from the mouth of the Aichi River on the east shore of Lake Biwa, and the lakeshore erosion became intense. It was also confirmed that the lakeshore energy flux decreases on the right bank of the inflow river delta in the vicinity of the mouth of the Chomeiji River from the Biwako Bridge, and the vegetation belt tends to be distributed easily.

 Based on the above results, the restoration areas, where vegetation belt conservation should be given priority, were picked up so that appropriate countermeasures were suggested. It was proposed that a substantial response under the cooperation of related organizations was made by utilizing the framework of the Lake Biwa Conservation and Restoration Plan with a view to lake basin governance.

 Probable Precipitation is generally used to arrive at estimates for planning, design and flood management for sewer and river basin. It is an urgent task to devlop a flood control plan that take into consideration the impact of climate change. In this study, we calcualted probable maximum precipitaion for future climate in Kinki region from output rainfall of climate model using d4PDF which is massive ensemble climate prediction data. As a result, it was shown that it is necessary to use the rainfall suitable for the region or district, because the probable maximum precipitaion differs depending on the area. Current sewer drainage capacity will be insufficient for future rainfall for 10 years return period. However, the addition of green infrastructure such as wetlands reduces peak runoff and the runoff stormwater will be released by current drainage systems.

 In recent years, life-prolonged landfill sites may cause problems such as aging facilities and changes in leachate quality. On the other hand, life-prolonged landfill sites might be affected by future climate change. In particular, the internal storage and overflow of leachate from landfill sites due to heavy rain are concerned. Therefore, this study conducted a questionnaire survey on landfill sites nationwide in oder to understand actual situations of the above-mentioned problems systematically. As a result, the actual situations on problems related to life-prolongation, leachate management, such as internal storage and changes in leachate quality, and disaster response. In conclusion, it is necessary to consider the planned implementation of inspections and repair for landfill sites toward the life prolongation and climate change. In particular, this study suggested the necessity of redesigning the leachate treatment facility scale and treatment processes.

 This paper take up “mist spraying” as an case study of climate change adaptation measures and technologies in heat wave which spread in many regions through literature survey and interview. The main results demonstrate as follows; i) the emergence of key technology that responds to the local background issues is a prerequisite for diffusion in the local community and economical factor, institutional factor, social factor, and oraganizational factor are also significant. ii) the values that the technology contains have been changed as diffusion among regions. The local climate change adapttion center that will be established in each region based on the Law is required to function as a hub of policy transfer network with storing these knowledge of these studies.

 “Regional Circular and Ecological Sphere (R-CES)” is a new approach for simultaneously achieving environmental, social, and economic benefits in local scale. It was proposed in the Fifth Environmental Basic Plan of the Government of Japan in 2018. Environmental systems research and R-CES have common interest in many aspects. In this research, we aim to propose basic framework for systems researches refereeing R-CES. As a preparatory work, we propose three “principles” of development of R-CES which consists of “Goals”, “Method”, and “Conditions”. After reviewing related area-based sustainability research, common framework of actions for developing R-CES is defined and their structuring and visualization method is proposed.

 Cities and human settlements will be the keys to achieving global Sustainable Development Goals (SDGs). All cities aim to increase prosperity, enhance resilience and environmental sustainability, especially in developing countries. While how to promote the low carbon city transition and achieve the SDGs targets are the emerging challenges. Few researchers have considered the coupling effect of comprehensive countermeasures to achieve the SDGs targets and the interactive process of actions and scenarios design. To fill in the research gaps, this study (1) Develop an integrated ExSS model, to analyze and predicate the different countermeasures of different sectors' contributions to the low carbon development. (2) Identify challenges and problems in the city development based on the field survey and dialogues with local stakeholders. (3) Evaluate SDGs future city development scenarios and mitigation actions with considering cross-industrial sectors. Bogor city is selected as a case, then applied the integrated model to conduct a systematic analysis. The results showed that, the energy efficiency improvement in the commercial and residential buildings are the main contributors to emission reduction of the 2030CM scenario. The emission reduction amounts by the mitigation actions accounts for 38.1% and 18.2% of the total emission reduction amount, respectively. The energy supply sector, transport sector, and the waste management sector also make significant contributions, the emission reduction amount accounts for 23.5%, 4.1%, and 3.9% of the total emission reduction amount of 2030CM scenario, respectively.

 The results and countermeasures are introduced as a basis for the need to actively solve the challenges in the city, highlighting the effective ways of achieving four key SDGs. This study not only helps the local government shift to more environmentally sustainable and economically successful development pathways but also provides inspiration for comprehensive climate change mitigation solutions from the co-planning perspective.

 Maintenance of aging infrastructure is an important issue in Japan, which is facing a declining population. In particular, since water pipes that serve as lifelines are buried underground, it is impossible to directly check the state of deterioration, and it is extremely difficult to detect water leaks from underground water pipes at an early stage. In order to overcome these issues, the development of health monitoring technology for infrastructure has been promoted recently, and the application of maintenance methods using high-sensitivity sensors and AI technology has been developed. In this study, we focused on the difference of deterministic properties of time series data of water leak sound, and visualized sound information on a two-dimensional plane using recurrence plot (RP). Then, we develop a leak discrimination model based on a convolutional neural network (CNN) using the visualized images. As a result of comparing the accuracy of water leak discrimination with the CNN model, an average accuracy rate of more than 90% was obtained, confirming the effectiveness of the proposed method combining RP and CNN.

 According to the IPCC’s Fifth Assessment Report, it is highly probable that as global mean temperatures increase, there will be more frequent hot temperature extremes, and it is very likely that there will be more frequent extreme precipitation in the world. We evaluated future changes of the rainfall and temperature characteristics in Hyogo Prefecture usingn a large ensemble climate prediction dataset (d4PDF). We predictedthe frequency, magnitude, and duration of future droughts by a water budget equation model. As a result, it has become clear that, in the future climate, the number of days with extremely high temperatures and the number of days without rain will increase. Furthermore, it was shown that the frequency, scale and duration of drought risk will be higher in the future climate.

 Earthquake resistance of the water pipe distribution network has been recently required for earthquake disaster risk reduction. In particular, from the perspective of disaster resilience, it is considered necessary to identify the effects of Material and human resources and restoration priorities on the restoration process. The objective of this study is to develop a numerial simulation model that can express the water sup-ply situation of the daily pipe network after the earthquake disaster. The discretized damage estimation focusing on individual pipe, the pipe network analysis model after the earthquake and the emergency res-toration model was developed, and verified the restoration process that changes depending on the number of emergency restoration groups and restoration priority. The results show that sufficient number of group and prioritizing the pipelines in a regional mesh with a large population of water outage would enable ef-ficient restoration.

 In this study, in the Tajima area of Hyogo Prefecture, the consolidation of sewage treatment facilities were classified into sewage intensive treatment type by conversion of abolished facilities to relay facilities and sewage dispersion treatment type by transfer to municipal installation type public septic tanks, classified them into two cases and compared and evaluated using three evaluation indicators of cost, greenhouse gas emissions (hereinafter "GHG emissions"), and energy consumption. For each update case, two cases in which the time of renewal is a normal update type and an early update type, including 4 cases that are combined them and a current case that maintains/renews the current number of facilities as a standard, five updated cases were targeted. Evaluation result, sewage dispersion treatment/early update type was shown that the initial cost was 6.8%, the running cost was 7.4%, and the energy consumption was reduced by 4.1% from 2020 to 2050 compared with the current status case.

 In this study, effects on maintenance costs reduction were analyzed invarious types of sewage treatment plants all over Japan by introducing information and communication technology (ICT) with different computing environment. As a result of the analysis, it was revealed that maintenance cost reduction was observed only for about 6% of 2,144 sewage treatment plants all over Japan, assuming that ICT are impletemented individually. In particular, there is no treatment plant with maintenance cost reduction effect for 14 prefectures which have a lot of medium or small sized treatment plants. On the other hand, it was also revealed that maintenance cost reduction effect by ICT depends on system deployment such as on-premise and cloud computing, assuming that ICT is implemented over a wide area with local governments’ collaboration based on prefecture’s initiative.

 Maintaining the quantity and quality of public services will be becoming the big issues in Japan, where the population is declining. The situation is similar in the sewage and waste disposal fields, and measures should be suitably carried out. The introduction of garbage grinders can be expected to increase the efficiency of waste disposal by reducing combustible waste and increasing heat value. On the other hand, the garbage thrown into the sewage system may cause adverse effects due to an increase in water quality load on sewage treatment. This study numerically predicted the change of water quality load reaching the sewage treatment plant based on data from the model experiment for the research of water quality change loaded by discharged garbage in sewer pipeline. GHG emission from sewage treatment and combustible waste treatment were examined by reflecting the water quality predicts. As the result, it was made clear that the reduction by combustible waste was greater than the increase in the sewage treatment by DP discharge, and the introduction of garbage grinder would be contributed to the reduction of GHG emissions.

 Impacts of providing information on marine plastic issues on the consent to abolishing plastic bags at supermarkets/convenience stores and plastic straws were evaluated via a consumer survey throughout Japan.The result shows that consumers who agree to abolish plastic straws but disagree to abolish plastic bags in convenience stores, and have a high awareness of environmental issues have turn to agree to abolish plastic bags by providing information. Providing information could not change the attitude of consumers who disagree to abolish both plastic bags and plastic straws, but help to mitigate their awarenesses that the lack of a plastic bag is inconvenient and carrying a shopping bag is bothersome.

 However, consumers have selected and processed privided information according to their preferences to the abolition of provision of shopping bags and straws. For equalizing the level of comsumers' comprehension of information, it is necessary to provide information in which the causal relationship among factors related to the marine plastic problem was shown so that it is not decoupled.

 Biogas Plants (BGP) has various effects (environment, economy and society) to local community as well as production of new income as electric power. However, there is no study that clarify the overall picture of effects of BGP on local community. The purpose of this study is to clarify the effects of BGP on the dairy region from the viewpoint of dairy farmers and local administration. Two towns in Hokkaido, Okoppe town and Kamishihoro town, were selected as research field. These towns already have BGP to treat the dairy manure and these facilities was established by cooperation from local administration. The overall picture of the BGP introduction effect on the dairy region was shown qualitatively. Odor problem and low quality and quantity of grass from the perspective of dairy farmers were original problem in both town. BGP can solve these original problems. Additionally, it was found that the innovation of work was caused the leisure time created by outsourcing manure treatment. It was revealed that the range of BGP effect was wider than supposed effect (energy and environmental field) at design phase. BGP can contribute to increase employment, establishment of relation with other community and environmental education in dairy regional community.

 The results of forecasting domestic water demand in the long term are important for planning wa-ter supply facilities and operation and management systems. In Japan, recently, domestic water de-mand has been decreasing because of the progress of a water saving society such as spread of water-saving equipment. With the spread of various types of water use equipment and the diversification of lifestyles, it is required to forecast the future water demand at the household level when forecasting water demand. In this study, WEB questionnaire survey was conducted to grasp the latest water usage. And, long time changes of water demand structure was analyzed by questionnaire surveys which were conducted over three periods.

 As a result, the unit water consumption decreased over time. In addition, water use behaviors such as the frequency of laundry and water saving behavior directly affected the unit water consumption, but the magnitude of the effect changed over time.

 The balance between water use and disaster risk management is a global issue in sustainability of lowland areas.

 The aim of this research is to raise awareness of disaster prevention and raise awareness of SDGs Goal 11 from the disaster prevention aspect. Therefore, in this practice, we will develop an ESD program through exploratory learning that includes production and exchange activities based on the learning composition table that we developed, based on the experience of the heavy rain disaster in August 2019 by public junior high school students.

 The ESD program to be developed is an extension of the watershed learning that we have studied so far, in addition to fostering humanity, respecting relationships and connections, and introducing each perspective of ESD.

 From the questionnaire survey, the awareness of disaster prevention and the willingness to build a sustainable city from the viewpoint of disaster prevention were recognized.

 This study is an example of an ESD program based on an interdisciplinary and comprehensive learning composition table that introduces the concept of connecting a heavy rain disaster in a lowland to an educational site, with the aim of achieving 11 SDGs from the disaster prevention perspective.

 To know whether place attachment influences pro-environmental behaviors and people’s socio-economic situations affect place attachment, relations pro-environmental behaviors and place attachment were explored using 47 prefectures data, collected by the government, and private sectors and researchers. Seven latent factors were identified as consciousness to place and community, and their influences on pro-environmental behaviors were examined by multiple regression analysis. The collected pro-environmental behaviors were statisitically classified and nine representative activities were selected as a representative and grouped to three different behavioral tendencies. One classification of the behaviors was considered to be related not just to the aim on pro-environmental effects, but to some other sense of value in the people's daily life, and found to be eminently related to two place and community consciousness indices. They were found to be related to the awareness of “nature” and “local history” of their living place. Further, these awarenesses were found to decrease with the increase of residential mobility and superior academic background.

 The purpose of this study was to develop a heat balance model of a rotary kiln and stoker furnace, which is often used as an industrial waste incinerator, and to estimate the GHG reduction effect of the energy recovery technologies. A heat balance model was developed that takes into account the heat and exhaust gas characteristics of a rotary kiln-stoker furnace that can accept a variety of industrial wastes, and the presence or absence of a sludge dryer process, which is characteristic of industrial waste reactors, to quantify the GHG reduction effects of two types of energy recovery technologies, depending on the difficulty of installation. As a result, it was found that it is necessary to create a precise heat balance model when introducing binary power generation, and it is more effective to update the boiler that uses saturated steam than superheated steam when updating the waste heat boiler.

 In this study, we developed a model to estimate the disaster waste generation values in municipalities. The estimated values will be used to formulate or revise disaster waste disposal plans drawn by municipalities as countermeasures against the Nankai Trough Earthquake, especially for those areas that require special strengthening. We also used the model to carefully examine all the points that must be considered when estimating the amount of disaster waste generation. In addition, inland municipalities where the values are smaller than existing disaster waste generation values and those whose values are higher were extracted.

 The results showed that existing disaster waste generation values do not necessarily match the situation of municipalities. Thereafter, we proposed an effective way to formulate or revise future disaster waste disposal plans.

 As a method of remediation and recycling for the radioactive cesium contaminated soil caused by the explosion of Fukusima Daiichi Nuclear Power Plant, it is promising to apply soil size separation that can be treated in large quantities and at relatively low cost.. In this study, fine size classification to separate particles under 20 m is proposed in order to increase the concentration rate and the recycling rate. As a post-treatment technology, solid-liquid separation by microbubble flotation (MBF) was performed in order to solve the problems in sedimentation separation using a general coagulant precipitant.

 Since most of the target soil is derived from farmland, a combination of a foaming agent and a collector that has a wide range of effects is selected for inexperienced target mud water containing not only soil particles but also organic fine particles. It was confirmed that the target turbidity could be achieved by finely adjusting the flow rate and the amount of collector. By this combined system of fine soil size separation and MBF, it was confirmed that radioactive cesium could be concentrated in the fraction of 20 m or less, and the possibility as a new practical volume reduction method for radioactive Cs contaminated soil was shown.

 Centralized reduction melting of incineration residues has been put into practical use as one of the efficient methods for recovering metal resources contained in waste. On the other hand, the collection target of small home appliance recycling has not been reached, and the collection efficiency is particularly low in cities with a population of 1 million or more.

 In this study, we have proposed a system that achieves efficiently metal resource recovery equivalent to the collection goal of recycling small household appliances by introducing centralized reduction melting and recovering metal from incineration residue in parts of cities with a population of more than 1 million, where collection efficiency of small household appliances is low. As a result of the evaluation of GHG emissions and trial economic evaluation, although the introduction of centralized reduction melting increased GHG emissions compared to the recycling promotion of small household appliances, the overall cost could be reduced.

 For the establishment of Recycling-based Society, Stock-type Society becomes increasingly important. Material stock plays an important role in the society and serves someone well in one way, whereas it has inevitable impact on material flow. For the reason that material stock is inextricably linked with material flow, the excess material stock can induce unnecessary resource input and increase waste generation from obsolete stock. To bring down high-quality material stock for the future generation, proper management of materials stored or hibernating in the society is required. In order to grasp the status of stock, material stock should be estimated and evaluated with in-use rate. In this study, by the method of lifespan modeling approach, material stock in Japan’s residential buildings and the amount of that obsolete stock/in-use stock were estimated. As a result of the estimation, there were 5.2 billion tons of residential building in 2018. In the amount of material stock in empty houses out of residential buildings, the amount of obsolete stock was estimated at 0.3 billion ton. As the number of residential building keeps increasing, the amount of obsolete stock is expected to increase in future.

 In this study, 4 species of indoor decorative plants, which were considered to be widely observed in the city, were selected as research subjects, and the growth distribution was investigated in three areas in Nara city. Then, the distribution characteristics of each species were grasped by comparing them by region and land use type. Analyzing the growth distribution map and comparing the plant density, the area around Shin-Omiya Station was the highest at 8.62 plants/ha. The plant density was markedly lower at 1.56 plants/ha around Tomio Station and 0.25 plants/ha around Narayama Station. In the comparison by land use type, all plant species showed the highest density in residential areas around Shin-Omiya Station. When comparing the age of the buildings, it was found that plants were concentrated in the area where there were many houses more than 30 years old. Among the plant species, Crassula ovata was the most common, and the result was different from that of Chlorophytum comosum, which was the most common in Osaka and Hyogo Pref..