研究者詳細 - 藤原　健史

論文 - 藤原　健史

分割表示 143 件中 1 - 20 件目／全件表示 >>

The Perception of Plastic Waste and Composition of Boathouse Waste in Floating Villages on Tonlé Sap Lake, Cambodia 招待査読

Habuer, Takeshi Fujiwara, Spoann Vin, Phat Chandara, Makoto Tsukiji

Clean Technologies and Environmental Policy 2024年12月

Optimizing cell phone recycling process: Unraveling rational and emotional drivers of consumer recycling participation using PLS-SEM and fs-QCA 査読

Yuxin Du, Habuer, Takeshi Fujiwara

Process Safety and Environmental Protection 191 218 - 233 2024年11月

生ごみ分別回収済の可燃ごみを炭化処理することによる温室効果ガスの排出削減効果

遠入野生, 藤原健史

EICA 29 ( 2/3 ) 2024年10月

Understanding driving forces of food waste separation intention to enhance regional and local solid waste planning: application of PLS-SEM and multi-group analysis 査読

Cuong Le Dinh, Takeshi Fujiwara, Song Toan Pham Phu, Habuer

Environmental Science and Pollution Research 31 ( 38 ) 50654 - 50669 2024年8月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Springer Science and Business Media LLC

Abstract

This study extended the theory of planned behaviour (TPB) and applied it to analyse influencing factors of food waste separation intention (FSI) among households in central Vietnam. Partial least squares structural equation modelling (PLS-SEM) was employed to analyse the data. The heterogeneity of factors contributing to FSI in cities of three levels was examined using multi-group analysis (MGA). The results indicate that attitudes, subjective norms (SN), perceived behavioural control (PBC), awareness of benefit (AB), information publicity (IP), facility availability (FA), and trust significantly affected FSI of households. MGA results indicated the heterogeneity of impacts of PBC and attitude on FSI of households among three municipal levels. The results will serve as basic data for waste officers, solid-waste management project leaders, non-governmental organisations (NGOs), and other related stakeholders to lay the foundation of food waste management planning in terms of regional scale and local scale. This study will also aid the creation of a circular economy by providing a scientific base for enhancing food waste separation at source in central Vietnam.

DOI： 10.1007/s11356-024-34485-2

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その他リンク： https://link.springer.com/article/10.1007/s11356-024-34485-2/fulltext.html

脱炭素化に向けた廃棄物由来バイオガスのごみ収集への有効利用に関する研究査読

山下温大, 宗村健太, 藤原健史, 哈布尓

環境システム計測制御学会(EICA) 2023年10月

Application of an Integrated Granular and Suspended Sludge Methane Reactor for a Two-Stage Anaerobic Digestion System to Deal with Biodegradable Municipal Solid Waste 査読

Pham Van Dinh, Takeshi Fujiwara

Fermentation 9 ( 8 ) 1 - 12 2023年8月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study aims to investigate the performance of a two-stage anaerobic digestion system using a hybrid methane reactor to deal with biodegradable municipal solid waste. The reactor allowed both suspended sludge and granular sludge to work together. The feedstock was fermented in one continuous stirred tank at different pH conditions for 5 d. Furthermore, the liquid hydrolysate was diluted and pumped into a methane reactor with different organic loading rates. In the fermentative reactor, raising the pH condition from 4.5 to 6.5 caused a sharp increase in volatile fatty acids concentration, mainly due to the increase in acetate and propionate. The efficiency of the methane reactor was proven by the results of hydrodynamic analysis and biogas production. The relationship between biogas production and operating parameters in this reactor was modeled using a quadratic multivariate regression model. Overall, by maintaining the fermentative reactor at a pH of 6.0–6.5, the methane reactor was able to achieve an organic loading rate of 7.6 g-TS.L−1·d−1 with outstanding biogas quality and yield. In terms of microbiology, the most dominant phyla in the reactor included Firmicutes, Bacteroidetes, Proteobacteria, Euryarchaeota, Synergistetes, and Chloroflexi. Among them, the species with the highest relative abundance in granular sludge was Firmicutes, while that in suspended sludge was Bacteroidetes.

DOI： 10.3390/fermentation9080720

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Biogas Production and Energy Balance in a Two-Stage Anaerobic Digestion of Fruit and Vegetable Waste: Thermophilic versus Mesophilic 査読

Pham Van Dinh, Takeshi Fujiwara

Fermentation 9 ( 7 ) 1 - 11 2023年7月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

This study aimed to investigate biogas production and energy balance in a two-stage anaerobic digestion system of fruit/vegetable waste under thermophilic and mesophilic conditions. Firstly, the feedstock was hydrolyzed and acidified in an acidic reactor at 37 °C with a retention time of 5 d. Then, the liquid hydrolysate was collected and pumped into an up-flow methane reactor under a mesophilic temperature with a retention time of 5 d and a thermophilic condition with a retention time of 3 d. The experimental results showed that in the thermophilic methane reactor, the COD removal, biogas yield, and methane concentration were 96.3%, 492 mL/g-VS, and 70.4%, respectively. These values were 3%, 10%, and 3% higher, respectively, than those obtained in the mesophilic methane reactor. In terms of energy, the mesophilic and thermophilic methane reactors consumed the same thermal energy demand for temperature control. They were much lower than the heat values produced by the power engine. The two-stage anaerobic digestion system using a thermophilic methane reactor obtained a gross energy of 11.20 kJ/g-VS and a net energy of 9.83 kJ/g-VS. These values were 13.2% and 14.8% higher, respectively, than those obtained by the system with a mesophilic condition. Moreover, the use of a thermophilic reactor helped reduce the reactor volume by 40%, leading to significant investment cost savings.

DOI： 10.3390/fermentation9070601

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Composting Activities in Vietnam – The Situation, Problems, and Challenges 査読

Duy Bao Nguyen, Takeshi Fujiwara, Cuong Le Dinh, Song Toan, Pham Phu

Chemical Engineering Transactions ( 106 ) 613 - 618 2023年

An Analysis of Biodegradable Solid Waste Flow in Vietnam 査読

Cuong Le Dinh, Takeshi Fujiwara, Song Toan, Pham Phu

Chemical Transactions ( 106 ) 619 - 624 2023年

Effects of effluent recirculation on two-stage anaerobic digestion in treatment of biodegradable municipal solid waste 査読

P. V. Dinh, T. Fujiwara, A. N. Peni, C. K. Tran

Global Journal of Environmental Science and Management 9 ( SI ) 35 - 46 2023年

記述言語：英語掲載種別：研究論文（学術雑誌）

BACKGROUND AND OBJECTIVES: Advantages such as high stability and high biogas production when recirculating the effluent stream in two-stage anaerobic digestion systems have been demonstrated on a variety of substrates, but there is limited information regarding the use of this practice on organic municipal waste. Therefore, this study aimed to investigate how effluent recirculation affects the two-stage anaerobic digestion of biodegradable municipal solid waste. METHODS: Firstly, biodegradable municipal solid waste substrate was fermented under conditions of 12 percent initial total solids and a temperature of 36 degrees Celsius for 5 days. After that, the substrate continued to be diluted using tap water or the effluent stream with a rate of 2:1. In the case of using the effluent stream, the experiment was further performed with dilution rates of 3:1, 1:1, and 1:2. Then, the liquid part was collected and pumped into the methane reactor at an organic loading rate of 7.64 grams of total solids per liter per day at 36 degrees Celsius. The methane reactor was an up-flow reactor that contained both granular sludge and suspended sludge. The effectiveness of the experimental stages was evaluated through biogas production and chemical oxygen demand removal. FINDINGS: In the fermentative reactor, using the effluent stream to dilute solid-state feedstock helped keep the reactor stable at pH 5.5 without alkali addition. In the case of using tap water for dilution, it required a dose of 115.8 grams and 75.3 grams of sodium hydroxide per kilogram of volatile solids to attain pH conditions at 6.5 and 5.5, respectively. Maintaining the reactor at pH 6.5 increased the concentration of fermentation products compared to pH 5.5, including 5.9 percent total chemical oxygen demand, 5.5 percent soluble chemical oxygen demand, and 10.6 percent total volatile fatty acids. In the case of recirculating the effluent stream in the methane reactor, increasing the dilution rate from 0.5 to 3.0 resulted in a methane yield of 227.5-278.9 milliliter per gram of volatile solids and 85-93 percent chemical oxygen demand removal. The methane reactor’s best digestion performance was attained at recirculation rate 2. Methane formation mainly occurred in granular sludge via the hydrogenotrophic pathway. Methane formation in suspended sludge occurred in a secondary manner, mainly via both the hydrogenotrophic and acetotrophic pathways. Among methanogen families, Methanobacteriaceae was found to have the highest relative abundance (7.5 percent in granular sludge and 0.8 percent in suspended sludge). CONCLUSION: Recirculating the effluent provided significant benefits, including the ability to stabilize the hydrolysis process and increase the methane yield. A recirculation rate of 2 to obtain a total chemical oxygen demand of 35.2 grams per liter was the best condition for methanogenesis. Acetotrophic methanogens were better adapted to difficult conditions than hydrogenotrophic methanogens. The formation of methane mainly occurred in granular sludge via a dominant hydrogenotrophic pathway. Methane formation in suspended sludge occurred in a secondary manner, mainly via both the hydrogenotrophic and acetotrophic pathways. Among methanogen families, Methanobacteriaceae was found to have the highest relative abundance.

DOI： 10.22034/GJESM.2023.09.SI.03

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A Perception Survey of Plastic Waste in Floating Villages on Tonle Sap Lake, Cambodia 査読

Habuer, Sakinah, binti Abdullah, Takeshi Fujiwara, Spoann Vin, Phat Chandara, Makoto Tsukiji

Chemical Engineering Transactions ( 106 ) 391 - 396 2023年

バイオガス利用によるごみ収集時の二酸化炭素排出量の抑制-軽油トラックおよび天然ガストラックとEVトラックの評価- 査読

山下温大, 宗村健太, 藤原健史, Habuer

EICA 28 ( 2/3 ) 19 - 27 2023年

ORIENTED-PLANNING SOLID WASTE MANAGEMENT SYSTEM IN VIETNAM TOWARD SUSTAINABILITY - MINIMALISM OR OPTIMIZATION 査読

Song Toan Pham Phu, Takeshi Fujiwara, Cuong Le Dinh

Environmental Engineering and Management Journal 21 ( 9 ) 1533 - 1543 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

In Vietnam, the rapid development of the tourism industry has led to significant challenges in the management of municipal solid waste. In Hoi An city (HAC), the solid waste management (SWM) system in the tourism area (TA) in downtown is facing many urgent problems such as the overload of waste, the inefficiency in the collection system, and the loss of revenues from tipping fee. Aiming to reduce these gaps, five scenarios of the SWM models are built based on the practical issues, the assumption on enhancing of SWM practice, improving the SWM collection, and approving the waste regulation from local government. The optimisation and feasibility of an SWM model were analysed and assessed based on the efficiency of the collection system, the enhancement of recycling practice, the consensus of stakeholders, the favourability for treatment, and the optimisation of economic benefits. The results revealed that the SWM scenario 1 (S1) and S2 get a more positive response from stakeholders (especially commercial sectors) by the high consensus and willingness to pay the higher tipping fee (1.2 times) due to the minimalism in the SWM practice at source. While S3 and S4 clearly show more optimization in sustainable waste management such as techincal efficiency, economic affordability and effective environment. The upgraded process of the SWM system is suggested to gradual apply from S0 to S3 and S4 under the monitoring of the government and the support from social organisations. It should be an oriented-plan of the SWM system in HAC toward sustainability.

DOI： 10.30638/eemj.2022.136

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Developing a dataset for the expected anthropogenic mercury release in China in response to the Minamata convention on mercury. 査読国際誌

Habuer, Takeshi Fujiwara, Masaki Takaoka

Data in brief 42 108280 - 108280 2022年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

This paper contains supplementary data in support of a research paper published [1] regarding the expected anthropogenic mercury release in China in response to the Minamata Convention on Mercury (MCM). The dataset provided within this article contains a set of excel spreadsheets. Each spreadsheet contains filtered (collected) and analysed data, i.e., parameters, collected data, calculated and summarized results for mercury distribution by the category of mineral production, intentional uses, secondary metal production, extraction and combustion, and waste treatment in a specific year. The collected (filtered) data in this article consist of the input factor (IF), activity rate data (ARD), output scenario (OS), initial distribution factor (iDF), and redistribution factor (rDF). IF was from the default IF in the United Nations Environment Programme (UNEP) Toolkit Level 2 and published scientific papers. ARD was obtained from the U.S. Geological Survey database, China Statistical Yearbooks, and published scientific papers. The OS content was from the default OS in the UNEP Toolkit Level 2 and published scientific papers. iDF was from the default distribution factor (DF) in the UNEP Toolkit Level 2 and published scientific papers. rDF was from published scientific paper. The mercury input was calculated using IF and ARD. The mercury release to different media in the initial distribution step was calculated using the mercury input and iDF. The release of mercury to the final sinks in the redistribution step was calculated using the amount of sector-specific treatment/disposal, product or by-product, and rDF. The dataset with combination of the collected (filtered) and analyzed data can contribute to an understanding of differences in anthropogenic mercury release before and after implementation of the MCM, especially considering technology transformation in China. Government policymakers involved in hazardous waste management, especially those working on MCM, and engineers and scientists interested in hazardous waste management may benefit from these data. The data can be used for identifying the environmental impact of anthropogenic mercury release before and after the MCM in China. The data can facilitate the creation of strategic management policies for mercury as the MCM is implemented in China.

DOI： 10.1016/j.dib.2022.108280

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Greenhouse gas mitigation by integrating waste treatment system toward low-carbon city in Vietnam 査読

Song Toan Pham Phu, Takeshi Fujiwara, Dinh Cuong Le, Duy Bao Nguyen

Blue-Green Infrastructure Across Asian Countries: Improving Urban Resilience and Sustainability 465 - 473 2022年3月

記述言語：英語掲載種別：論文集(書籍)内論文

Environmental pollutions and greenhouse gas (GHG) emissions are among the dark sides of development and have been one of the critical driving forces of climate change. GHG is emitted from various activities, of which the waste treatment system is a significant source. This chapter describes the results of mitigating GHG by enhancing the solid waste management (SWM) system toward a low-carbon society in Hoi An City (HAC), Vietnam. The results showed that landfilling has the highest GHG emission with 808 kg CO2-eq per tonne of waste, while incineration and composting emit on average 438 and 172 kg CO2-eq/tonne of waste, respectively. The average carbon footprint value of waste in optimal SWM system (S3 and S4) is 337 and 307 kg CO2-eq per tonne of solid waste treated. The GHG amount emitted from the minimalist SWM system (S1 and S2) is higher by 547 and 536 kg CO2-eq/tonne of waste treated, respectively. The higher the solid waste management practice, the lower the GHG emission. This study also builds the oriented planning on improving the SWM system in HAC (Vietnam in general) in the next decade. The optimal SWM scenarios (S0-S3-S4) will significantly contribute to mitigating GHG emissions.

DOI： 10.1007/978-981-16-7128-9_21

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Optimization of solid waste collection system in a tourism destination 査読

Cuong Le Dinh, Takeshi Fujiwara, Misuzu Asari, Song Toan, Pham Phu

Global Journal of Environmental Science and Management 8 ( 3 ) 1 - 18 2022年3月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

most famous tourist destinations in the world. This led to a rapid increase in solid waste generation,leading to problems and challenges in solid waste collection and management. This problem is alsobeing experienced by other developing countries of the world. Despite the existence of establishedwaste management strategies, targets set for the collection of recyclable waste have not been met.This study introduces solutions to the problems and challenges faced by the waste managementsector in Hoi An city and other developing countries. This study aimed to i) optimize the map of therecovery recycling stations in an urban community, ii) develop an effective solid waste collectionsystem, and iii) provide management tools to enhance recycling activities, contributing to improvingwaste management in Hoi An city.METHODS: The RRSs were integrated into a solid waste collection system in the urban communitiesof Hoi An City, were conducted through location-allocation analysis in a geographic informationsystem environment. Routing problems of carts were solved in the combination of the reschedulingof existing solid waste collection activities in the study site. The economic evaluation by scenarioswas also calculated for ten years to assess the feasibility of scenarios.FINDINGS: Thirty-four locations were identified and optimized to accommodate the RRSs and newcollection routes. The distances travelled and working time increased in proportion to the increasein waste separation effectiveness. Waste separation is vital to the effectiveness of the new solidwaste collection system. The optimal solid waste practice model (in scenarios 2 and 4) revealedthe positive results in improving the solid waste collection system, operating economy, and localadaptation.CONCLUSION: This study redesigned the solid waste collection system to solve the current problemsin the tourism destination of Hoi An city. This study contributed as a case study of integrating urbanrecovery recycling stations into optimizing a solid waste collection system in a tourism destination.Introducing strict waste separation was the pivotal first step in systematically upgrading the solidwaste collection system in Hoi An City. This study’s findings provide government officials and serviceproviders with methods that can be applied to solve the problems faced by Hoi An city’s existingsolid waste collection and management system.

DOI： 10.22034/GJESM.2022.03.09

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Promoting Chinese urban residents’ participation in source separation and recycling 査読

Binxian Gu, Yanbin Yao, Huimin Hang, Yulin Wang, Renfu Jia, Lingxuan Liu, Hui Ling, Xinyi Tang, Haijie Zhang, Zhiwei Wu, Yongxiang Wu, Takeshi Fujiwara, Yanchao Bai

Waste Management 139 290 - 299 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）

Source separation and recycling (SSR) for municipal solid waste is an important strategy for the transition to a circular economy and requires broader resident participation. How can residents’ participation in SSR be promoted? Here, we consider 13 cities in Jiangsu as microcosms of China. We quantify residents’ intentions to participate in SSR by distributing a validated questionnaire to 2,963 urban residents, analyze the results through structural equation modeling, and propose localized policy recommendations. We find that residents have positive attitudes toward SSR, although 92.6% of residents in southern Jiangsu were more willing to participate than those in northern Jiangsu (84.6%). Additionally, the influencing factors and their degree of influence on resident SSR participation intentions exhibit disparities across cities. “Accessibility of SSR facilities” simultaneously affects the 13 studied cities and is a key factor. “Environmental knowledge” and “environmental attitudes” are important impact factors, with occurrence frequencies of 84.6% and 69.2%, respectively. However, laws and regulations have no significant effect on residents’ SSR participation intentions. We recommend that the government create favorable external conditions related to facilities and services, promote extensive publicity and educational activities through various channels, and improve the effectiveness of SSR laws and regulations. Future SSR management strategies should be localized, flexible and comprehensive. This research could help decision makers in China and other countries design policy guides to promote SSR and help link current research areas to social development.

DOI： 10.1016/j.wasman.2021.12.032

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Effectiveness of oyster shell as alkali additive for two-stage anaerobic co-digestion: Carbon flow analysis 査読

Peni Astrini Notodarmojo, Takeshi Fujiwara, Habuer, Dinh Pham Van

Energy 239 ( Part C ) 2022年1月

Assessment of solid waste collection system-A case study in Hai Chau district, Danang city, Vietnam 査読

Cuong Le Dinh, Song Toan Pham Phu, Takeshi Fujiwara, Tra Qui Phan

2022 7th International Scientific Conference on Applying New Technology in Green Buildings, ATiGB 2022 37 - 42 2022年

担当区分：最終著者掲載種別：研究論文（国際会議プロシーディングス）

Over the last decade, urgent problems related to the waste management system of Da Nang city have been recognized. Therefore, research on the current status of solid waste management system and solid waste collection system is gradually becoming paramount. This study applied Geographic Information System (GIS) and Global Positioning System (GPS) to study the current status of the waste collection system in Hai Chau district, Danang city. The GPS devices were utilized and in-depth interviews were also performed to collect information and data about the waste collection system. Data were synthesized, processed, and analyzed by QGIS 3.4 and Excel 2016. Four teams were in charge of solid waste collection in the entire Hai Chau district. The average daily amounts of solid waste collected were 56t (Team 1), 42.4t (Team 2), 42.6t (Team 3), and 61.1t (Team 4). The coverage ratios and physical duplication ratios of the three teams were 36.5% and 51.1% (Team 1), 55.6% and 47.1% (Team 2), 51.4% and 34.4% (Team 3). The compaction truck of Team 4 only transferred solid waste from transfer station to Khanh Son landfill. The problems and challenges of the solid waste collection system were also highlighted with recommendations for the outcomes.

DOI： 10.1109/ATiGB56486.2022.9984120

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Reduction Potential of Anthropogenic Mercury Release in Malaysia 査読

Habuer, Takeshi Fujiwara

Chemical Engineering Transactions 97 205 - 210 2022年

担当区分：最終著者掲載種別：研究論文（学術雑誌）

Anthropogenic release of mercury, human exposure and environmental health are important and mercury management policies are required to effect significant change in Malaysia. To provide a useful information to facilitate the creation of strategic management policies for mercury as the Minamata Convention on Mercury is implemented in Malaysia, there is an urgent need to estimate the potential to reduce mercury release by applying different control measures, i.e. simple electrostatic precipitator and mercury-specific filter. Equally urgent is the need to clarify the alleviated environmental burdens from the reduced mercury releases by applying different control measures. Many researches have explored issues in terms of the mercury’ toxicity and the harm of mercury compounds worldwide. A lack of surveys to evaluate both on the reduction potentials and alleviated environmental burdens of mercury releases resulted in anthropogenic sources under different control measures has been observed. This study estimated the potential reduction and alleviation of the environmental burden of anthropogenic mercury released into the natural environment (air, water and land) in Malaysia under three emission control scenarios and identified the potential reductions. A life cycle impact assessment was applied to estimate an alleviated environmental impact under these scenarios. As a result, the environmental burden can be reduced by 77 % by applying the multipollutant emission control measures such as applying mercury-specific filter for coal combustion compared to no emission control measures. At this maximum, the harm to human health can be reduced by 3,730 disability-adjusted loss of life years and the harm to ecosystems can be reduced by 0.16 species/year. This study will assist decision makers to understand the magnitude of changes resulting from different emission control measures.

DOI： 10.3303/CET2297035

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