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Affiliation |
Engineering educational research section Department of Civil and Environmental Engineerring Program |
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Title |
Associate Professor |
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External Link |
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SEKITO Tomoo
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Degree 【 display / non-display 】
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Doctor (Engineering) ( 2001.12 Hokkaido University )
Research Areas 【 display / non-display 】
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Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Environmental systems for civil engineering
Papers 【 display / non-display 】
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外部濃度がセメント固化の易溶解性物質溶出量に及ぼす影響
土手裕，関戸知雄
宮崎大學工學部紀要 51 2023.10
Language：Japanese Publishing type：Research paper (bulletin of university, research institution)
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セメント固化飛灰の比表面積が易溶解性物質の溶出量に及ぼす影響
土手裕，関戸知雄
宮崎大學工學部紀要 51 2023.10
Language：Japanese Publishing type：Research paper (bulletin of university, research institution)
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太陽光パネル部材のコンクリート用細骨材としての環境安全性
土手裕，原田秀樹, 関戸知雄
宮崎大學工學部紀要 51 2023.10
Language：Japanese Publishing type：Research paper (bulletin of university, research institution)
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非降雨期間および周辺粒子粒径の固化飛灰からの易溶解性物質溶出量への影響
土手裕，関戸知雄
宮崎大學工學部紀要 51 2023.10
Language：Japanese Publishing type：Research paper (bulletin of university, research institution)
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Santiago J.R., Sekito T., Dote Y.
Minerals 13 ( 6 ) 2023.6
Publishing type：Research paper (scientific journal) Publisher：Minerals
Waste incineration is a widely used treatment method, and sustainable approaches are required to properly recycle large volumes of incineration ash to reduce environmental impacts and landfill space consumption. Studies have focused on the potential of recycling incineration ash as a replacement for natural aggregates in civil engineering applications, such as road construction. However, industrial waste incineration ash, such as waste tire incineration ash, contains hazardous heavy metals, such as lead and zinc that pose potential environmental threats. Moreover, few studies have investigated the leachability of these hazardous metals after long-term natural aging. This study investigates the long-term evolution of leachate chemistry, mineralogical transformation, and heavy metal fixation performance of a recycled roadbed material using ash from industrial waste incineration of waste tires and biomass (SFA). Additionally, field samples from a five-year pilot test site utilizing SFA were also examined. Regulatory leaching tests showed that the concentrations of Cd, Pb, As, T-Cr, and Ni were all below permissible limits even after five years of utilization. Long-term column leaching experiment results indicated that, compared to the total content of the SFA material, the leaching ratios of Pb, T-Cr, Cu, and Zn were 27%, 12%, 5%, and 0.1%, respectively. The SFA pH-stat leaching test results demonstrated that the mass release of the total content of heavy metals was relatively minimal, even under acidic pH conditions (pH < 4). Finally, profiles of pH and major ions in leachate from the column leaching experiment were simulated using HYDRUS HP1, implementing a dual-porosity modeling approach. In conclusion, despite containing hazardous heavy metals, SFA exhibits significantly low leaching rates over a long-term period.
DOI： 10.3390/min13060823
Books 【 display / non-display 】
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インバース・マニュファクチャリング ハンドブック
インバース・マニュファクチャリングフォーラム監修 （ Role： Joint author）
丸善株式会社 2004.3
Language：Japanese Book type：Scholarly book
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循環型社会構築の戦略
田中信壽，田中勝 編著 （ Role： Joint author）
中央法規出版 2002.3
Language：Japanese Book type：Scholarly book
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廃棄物処理総論
田中勝 監訳代表（ Role： Joint author）
エヌ・ティーエス 1998.6
Language：Japanese Book type：Scholarly book
MISC 【 display / non-display 】
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Valorization of post-consumer plastic packaging into a composite material
関戸 知雄
Proceedings of International Exchange and Innovation Conference on Engineering & Sciences (IEICES) 9 441 - 446 2023.10
Language：English Publishing type：Rapid communication, short report, research note, etc. (scientific journal) Publisher：九州大学大学院総合理工学府
Because of its strength and simplicity, many producers prefer to package their products with various forms of plastic. The use of plastic for packaging has increased significantly due to the change in lifestyle, which has subsequently led to an increase in plastic packaging waste. However, approximately 50% of plastics are produced in disposable single-use applications. Meaning, most of them are used as once-of products and in a short space of time, they become solid waste. From the environmental preservation perspective, recycling plastic waste can save natural resources and decrease energy consumption. Among the various types of recycling management approaches, the reuse of recycled plastic material in the construction sector is considered one of the environmentally friendly recycling methods. This approach will help reduce the depletion of natural resources used as raw materials for cement production.
DOI： 10.5109/7158037
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湿原を含む家畜埋却地周辺の環境モニタリング(<特集>2010年口蹄疫-残された課題を中心に-)
鈴木祥広，竹下伸一，関戸知雄，稲垣仁根
日本草地学会誌 58 ( 4 ) 269 - 276 2013.1
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：日本草地学会
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ドイツにおける埋立地に関する基準と廃棄物処理の動向
関戸知雄、土手裕
廃棄物学会誌 19 ( 1 ) 31 - 40 2008.1
Language：Japanese Publishing type：Research paper, summary (national, other academic conference) Publisher：廃棄物学会
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Sekito T., Matsuto T., Tanaka N.
Waste Management 27 ( 10 ) 2007.7
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution) Publisher：Waste Management
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畜舎排水処理施設におけるエストロゲンの実態調査
鈴木祥広、中村孝洋、小山久男、関戸知雄、土手裕、増田純雄
水処理技術 47 ( 1 ) 17 - 22 2006.1
Language：Japanese Publishing type：Research paper, summary (national, other academic conference) Publisher：日本水処理技術研究会
Presentations 【 display / non-display 】
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Influenct factors of variation of boron elution from coal bottom ash
Fukuda Michito, Sekito Tomoo, Dote Yutaka
Proceedings of the Annual Conference of Japan Society of Material Cycles and Waste Management 2023 Japan Society of Material Cycles and Waste Management
Event date： 2023
Language：Japanese Presentation type：Oral presentation (general)
Coal bottom ash (CA) generated from the bottom of coal boilers contains soluble boron and the level of the concentration often exceeds the Soil Environmental Standard value for Boron. The relationship between boiler combustion conditions and soluble ions in CA were investigated to estimate the factors that cause fluctuations of boron contained in CA. The results showed that there was no significant relationship between the soluble boron and the combustion conditions of the boiler. It was found that the soluble boron in CA has a relationship with concentrations of calcium and sulfate measured by the leaching test. It was found that the saturation index values of gypsum in CA obtained by PHREEQC software with higher soluble boron was larger than that with lower soluble boron. This result indicates that the soluble boron in CA was embedded or adsorbed in gypsum and the variation of soluble boron would be influenced by the amount of gypsum in CA.
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Development of leaching model of chloride ion from cement-solidified fly ash
Dote Yutaka, Sekito Tomoo
Proceedings of the Annual Conference of Japan Society of Material Cycles and Waste Management 2023 Japan Society of Material Cycles and Waste Management
Event date： 2023
Language：Japanese Presentation type：Oral presentation (general)
To develop a one-dimensional leaching model of chloride ion from cement-solidified fly ash, a calculation area was divided into surface dissolution dominant area and diffusion dominant area, and surface dissolution model and a diffusion model were applied to each area. The model parameters were determined by tank leaching tests. By comparing the degree of agreement between experimental values of each fractional leaching amounts of chloride ion and calculated values by the developed model and conventional diffusion model, the applicability of the developed mode was evaluated. The developed model could express the leaching phenomena of chloride ion from cement-solidified fly ash. The thickness of surface dissolution area was estimated to be about 1 mm, and it was considered that the surface dissolution occurred at the shallow surface of the cement-solidified fly ash. The periods where the leaching amounts by surface dissolution was dominant to that by diffusion were by the first 2 hours of the beginning of tank leaching tests. The developed model could express the leaching phenomena better than diffusion model by two days after the beginning of leaching tests.
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INFLUENCE OF SPECIFIC SURFACE RATE OF CEMENT SOLIDFIED FLY ASH ON LEACED AMAUNT OF SOLUBLE SUBUSTANCES International conference
Yutaka Dote, Tomoo Sekito
Event date： 2022.11
Language：English Presentation type：Oral presentation (general)
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Characterization of naturally aged cement solidified tire-derived fuel boiler fly ash recycled as a road-base aggregate material International conference
Santiago Rodolfo, Sekito Tomoo, Dote Yutaka
Proceedings of the Annual Conference of Japan Society of Material Cycles and Waste Management 2022 Japan Society of Material Cycles and Waste Management
Event date： 2022
Language：English Presentation type：Oral presentation (general)
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散水によるクリンカアッシュ中ホウ素溶出量の低減効果に関する研究
松尾 勝馬, 関戸 知雄, 土手 裕
廃棄物資源循環学会研究発表会講演集 2022 一般社団法人 廃棄物資源循環学会
Event date： 2022
Language：Japanese Presentation type：Oral presentation (general)
火力発電所から発生するクリンカアッシュ(CA)の埋立処分量の削減のために，少しでも付加価値の高い石炭灰の再利用方法を開発が求められている．本研究ではCAの有効利用方法として大腸菌群増殖抑制効果を調べ，その有効性を明らかにした．下水処理水に対して所定のCAを入れ培養しBGLB法により大腸菌群数を測定し，減少率を調べた．その結果，200ｍLの100倍希釈した試料水に対しCAを10g添加することにより大腸菌群の減少率が100%となり， CAの大腸菌群増殖抑制効果が明らかになった．また，CA添加量，試料水の希釈倍率，CAの粒径，振とう洗浄したCA，振とう溶出液，溶液pHを変えた実験を行い，大腸菌群増殖抑制メカニズムの解明を試みた．これらの実験結果より，CAの固体表面で大腸菌群増殖抑制が働いていると示唆された．
Grant-in-Aid for Scientific Research 【 display / non-display 】
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インドネシアのごみ銀行と集団回収による家庭ごみ資源回収システムの評価
2016.04 - 2018.03
科学研究費補助金 挑戦的萌芽研究
Authorship：Principal investigator
本研究では，インドネシア・マラン市を事例とし，ごみ銀行および集団回収による資源回収システムという２つの家庭ごみからの資源回収の方式に対して，住民の満足度，協力度，資源回収率，コストバランス，物質フローを明らかにする。これらの資源回収システムは，ここ数年，インドネシアで提案・実践され，自治体も資金援助をしている。しかし，それぞれの方式に対しての研究はこれまでに実施されておらず，非効率な資源回収方法が展開されている非常に可能性が高い。本研究の結果により，今後東南アジアで実施するべき資源回収方式を明らかにすることができ，資源の循環に貢献すると期待される。
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口蹄疫等による家畜の大量埋却処分地から発生する環境負荷発生量予測に関する研究
2011.04 - 2014.03
科学研究費補助金 基盤研究(C)
Authorship：Principal investigator
平成22年度に宮崎県で発生した口蹄疫を背景に、大量の家畜を埋却処分した埋却地から発生する汚染物質による環境影響について、実験により明らかにする。実験では、カラム実験、バッチ分解実験により汚染物質（浸出水による有機汚濁物質、腐敗性ガス）の発生速度、発生量を明らかにする。数値モデルでは、特に地下水への影響について考慮し、2次元の不飽和浸透式と、有機物および窒素化合物の分解・吸着による減衰を考慮した物質移動式により、埋却地下部から浸透した汚染物質の挙動を予測する。以上の結果を適切な埋却方法提案につなげる。
Available Technology 【 display / non-display 】
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廃棄物焼却残渣の有効利用と環境安全性評価に関する研究
産業活動で発生する廃棄物の循環利用に関する研究
途上国の資源循環と廃棄物処理戦略に関する研究Related fields where technical consultation is available：・廃棄物の有効利用と環境安全性評価
Message：廃棄物の循環利用を促進するために、工学や社会科学的視点から研究を行っています。