論文 - 伊藤 健一
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Ito K., Matsunaga M., Itakiyo T., Oishi H., Nukazawa K., Irie M., Suzuki Y.
International Journal of Sediment Research 38 ( 3 ) 469 - 480 2023年6月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Journal of Sediment Research
Sediment causes a serious problem in relation to dam function. A cooperative sediment sluicing operation has been under way since 2017 to prevent sediment from accumulating in dams in the Mimi River, Miyazaki, Japan. To achieve a smooth and stable operation, it is very important to determine the sediment source and a sediment transport system to maintain the dam's function. In the current study, the source and transport of sediment from the Mimi River basin have been analyzed with X-ray diffraction (XRD) to reveal the peaks of mineral species. The sediment samples were collected in the Mimi River basin from the Tsukabaru Dam to the sea in an area including 4 dams and 5 tributaries. In addition, the minerals in samples collected in 2014, before the start of the sediment sluicing operation, and from 2018 to 2020, after the start of the operation, were analyzed. An evaluation of the similarity of the sediment at each sampling point based on the X-ray diffraction peaks of mineral species showed that sediment distributed upstream was transported downstream in the year when the sediment sluicing was done. This result indicates that the sediment sluicing operation at dams ensured the continuity of the sediment distribution in the Mimi River basin. In addition, an investigation done in 2020 showed that sediment particles very similar to those of the upstream tributaries were deposited downstream because of extensive flooding caused by a large typhoon. The management of sediment transport has the greatest importance in a river basin where a dam is to be constructed. It is possible to trace the history of the sediment distribution and movement resulting from the operation of sediment sluicing by using sediment mineral analysis.
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Determination of geochemical parameters that control the spatial distribution of potentially toxic elements released from excavated shale at a temporary storage pit. 査読あり
Shoji Suzuki, Toshihiko Miura, Kenichi Ito, and Masahiko Katoh
Environmental geochemistry and health 47 ( 7 ) 259 2025年6月
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加速変質試験と液固比バッチ試験による長期カラム通水試験の酸化と溶出挙動の予測 査読あり
伊藤 健一, 小谷 護留, 伊藤 華奈子, 細堀 建司, 岡本 直人, 野田 典広
地盤工学ジャーナル 20 ( 1 ) 15 - 23 2025年3月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 地盤工学会
黄鉄鉱含有土壌からの長期溶出挙動を評価する曝露試験やカラム通水試験は長期間を要する。そこで，酸化を促進する加湿加温処理と液固比バッチ 試験を組み合わせたバッチ酸化溶出試験を考案し，火成岩を対象に上向流カラム通水試験と比較検討した。通水試験結果についてpH ORP相関図にネルンスト式を重ねることで通水中の酸化進行を確認した。また通水試験の累積溶出量から，物質が系外へ流出する溶脱が生じない場合の濃度を示す「累積平均濃度」を計算し，これをバッチ酸化溶出試験と対比した。検討の結果，カラム通水試験における硫酸イオンの長期溶出挙動についてバッチ酸化溶出試験で予測可能であることが示唆された。
DOI： 10.3208/jgs.20.15
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B13 盛土内の環境保全に向けたベントナイト複層覆土の検討
伊藤 健一, 小谷 護留
粘土科学討論会講演要旨集 67 ( 0 ) 81 - 82 2024年8月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等） 出版者・発行元：一般社団法人日本粘土学会
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長期カラム通水試験における酸化進行に関する加速変質試験との対比による考察 査読あり
伊藤 健一
第15回環境地盤工学シンポジウム発表論文集 15 83 - 87 2024年
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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加速変質試験を用いた自然由来重金属等含有岩石の溶出傾向における酸化の影響評価 査読あり
山田優子, 伊藤健一, 堀中敏弘, 鳥居和樹, 新谷広紀, 嵐正治
環境地盤工学シンポジウム発表論文集 15th ( 77-82 ) 2023年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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長期カラム通水試験における酸化進行に関する加速変質試験との対比による考察 査読あり
伊藤健一, 小谷護留, 伊藤華奈子, 細堀建司, 岡本直人, 野田典広
環境地盤工学シンポジウム発表論文集 15th ( 83-89 ) 2023年11月
担当区分：筆頭著者, 責任著者 掲載種別：研究論文（研究会，シンポジウム資料等）
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還元条件下での重金属等溶出試験法の確立を目指したアスコルビン酸濃度検討および異なる地盤材料への適用 査読あり
加藤雄大, 阿部夏季, 伊藤健一, 乾徹, 大山将, 加藤雅彦, 肴倉宏史, 土屋秀二
環境地盤工学シンポジウム発表論文集 15th ( 104-111 ) 2023年11月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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日本市場を目指す高度ICT 外国人材の渡日前教育と短期留学を活用した地域就業支援の取り組み 査読あり
伊藤 健一, 田阪 真之介, 森下 祐樹, 鵜澤 威夫
留学生交流・指導研究 24 ( 0 ) 65 - 79 2022年3月
担当区分：筆頭著者, 責任著者 記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：国立大学留学生指導研究協議会
地方における留学生就職では、留学生と地域の求める業種・職種の不一致という課題があった。そこで、宮崎大学、宮崎市、国際協力機構、地域企業等が連携してICT 分野を対象に渡日前教育と留学により高度外国人材の就業を支援する「宮崎－バングラデシュ・モデル」を実施した。渡日前教育B-JET では独自の日本語教材を製作・使用し、また日本的習慣を身に付けさせるために少人数クラスによる日本の小中学校のような時間割、教室運営とした。短期留学JIP では、日本語教育に加えてキャリア教育として就職予定企業へのインターンシップを行った。同時に、外国人に不慣れな受入企業側の異文化理解促進と受け入れ態勢の充実を図るため、企業担当者をチューターに据えた留学生の生活支援を行い、留学生・企業の双方が相互に学びながら高度人材の導入・受入れを進めるプログラムとした。 その結果、渡日前教育修了生の73％が日本企業へ、うち3 分の1 が宮崎県内企業へと就職した。
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Kei Nukazawa, Tomoya Itakiyo, Kenichi Ito, Shinji Sato, Hiroyuki Oishi, Yoshihiro Suzuki
Catena 203 105323 2021年8月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Catena
Knowledge of the provenance and transport processes of coastal sediments is central to safeguarding against coastal erosion. However, to date coastal sediments have been poorly investigated without considering complex artificial and natural attributes such as coastal structures and watershed geology of potential source rivers. In this study, mineralogical fingerprinting technique was used to track the sources of sediments along a coastline in southwest Japan with reference to sediments of outflowing rivers. The sediment samples were collected from 65 beach sites along the Miyazaki Coast and its surrounding coastal area, and five river sites nearby. To determine the size distribution and geochemical and mineralogical compositions of the sediments, grain size, X-ray fluorescence, and X-ray diffraction (XRD) analyses were performed. Subsequently, cluster analysis was used to classify mineralogically similar groups in terms of XRD peak intensity ratio. The coastal sediment clusters corresponded well to nearby riverine clusters, suggesting that the coastal sediments were primarily transported from these river watersheds, although uncertainty as contributions of oceanic flows might be involved. The concordance ascribes to the major geological classifications in the watersheds of major rivers, as well as smaller rivers flowing in the northern area (e.g., the Shimanto Supergroup and Osuzuyama Acid Rocks). In addition to the major tendency, we also observed potential effects of manmade structures on the coastal sediment prevalence; the mineralogical similarities decreased across jetties in the Hitotsuse River mouth. The vertical mineralogical distribution of the core sediment samples observed on the left and right banks of the Hitotsuse River mouth supported the general trend of uniform cluster patterns in each core sample with horizontally different clusters across the river mouth. Mineralogical analysis targeting both coastal and riverine sediments is effective for understanding the characteristics of sediment distribution, which in turn is useful for efforts devoted to protection against coastal erosion.
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Hirofumi Sakanakura, Kenichi Ito, Jiajie Tang, Mikako Nakagawa, and Hiroyuki Ishimori
Materials 14 ( 10 ) 2534 - 2549 2021年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Materials
Adsorption parameters such as the distribution coefficient are required to predict the release behavior of contaminants using advection-dispersion models. However, for potentially contaminant-releasing materials (PCMs) such as dredged sludge and coal ash, these parameters cannot be obtained by conventional adsorption tests. This study developed a method to determine adsorption parameters for PCMs from a set of batch tests conducted in parallel as a function of the liquid-solid ratio (LS-parallel test). This LS-parallel test was performed on sandy soil derived from marine sediment using liquid-solid ratios from 1 to 300 L/kg. The water-contact time was also changed from 10 min to 28 d to elucidate the kinetics or equilibrium of contaminants released from the sample. Adsorption parameters were successfully obtained if the substance was under adsorption control. A column percolation test was performed to confirm the effectiveness of the obtained parameters. Good agreements were observed for SO42− and B, but discrepancies remained for other substances such as F− and as suggesting that improvements are necessary in both the LS-parallel test procedure and the advection-dispersion model.
DOI： 10.3390/ma14102534
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不溶化層と縦樋による盛土内導水機能の有効性の検証 査読あり
小谷護留, 森下智貴, 三浦俊彦, 伊藤健一
第14回地盤改良シンポジウム論文集 419 - 426 2020年12月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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牛舎から発生するアンモニアガスへの消臭剤効果と消臭に影響 する因子の検討 査読あり
土手 裕, 林田 啓佑, 伊藤 健一, 関戸 知雄
宮崎大学工学部紀要 49 7 - 15 2020年9月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：宮崎大学工学部
The purpose of this research was to investigate the effect of Deodorant-A on ammonia gas, which is the main odor gas in a caw barn. Several investigations were conducted in both barns using Deodorant-A and barns not using Deodorant-A in order to identify factors affecting the concentration of ammonia gas above litter. Deodorant-A affected nitrification activity at a deodorant concentration of 1% or more. There were barns with high concentration of ammonia gas above litter using Deodorant-A and barns with low ammonia gas concentration not using Deodorant-A. As a result of multiple regression analysis, urea degradation activity was a biological variable showing a significant negative partial regression coefficient for ammonia gas concentration above litter. Calcium showed a significant, positive partial regression coefficient for urea degradation activity. It was suggested that the concentration of ammonia gas above litter might be decreased by increasing calcium and zinc, which showed a strong, positive correlation with calcium and was reported to inhibit the activity of urease.
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酸化マグネシウム系不溶化材による火山噴出物由来河川堆積物の不溶化処理に関する研究 査読あり
土手 裕, 伊藤 健一, 関戸 知雄, 尾花 誠一, 藤井 真吾
土木学会論文集Ｇ（環境） 76 ( 7 ) III_393 - III_401 2020年
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：公益社団法人 土木学会
本研究ではMgO系不溶化材による火山噴出物由来河川堆積物の不溶化処理効果について評価することを目的として，堆積物の不溶化処理，pH依存性試験，逐次抽出試験を行った．堆積物からBやAsなどの有害重金属等が土壌環境基準を大きく超える濃度で溶出した．堆積物をMgO系不溶化材で処理した結果，添加率の増加と共にpHは増加し，添加率10%でpHは8.0〜10.0に達した．添加率6%で全ての試料について全ての元素の溶出濃度を土壌環境基準値以下にすることができた．CdとFについては，pH2の強酸性でも不溶化効果が認められたが，B，As，T-Cr，PbについてはpH7以下では不溶化効果が低いことが分かった．火山噴出物由来河川堆積物をMgO不溶化材で処理した場合のAs, Bの不溶化メカニズムは，MgO, Mg(OH)<sub>2</sub>，Fe(OH)<sub>3</sub>への吸着である可能性が示唆された．
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液固比バッチ試験の適用についての検討 査読あり
岡本 直人, 細堀 建司, 野田 典広, 伊藤 健一
第13 回環境地盤工学シンポジウム発表論文集 2019年9月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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建設発生土からの砒素溶出特性の比較検討 査読あり
山田 優子, 伊藤 健一, 平山 利晶, 中島 誠
第13 回環境地盤工学シンポジウム発表論文集 2019年9月
記述言語：日本語 掲載種別：研究論文（研究会，シンポジウム資料等）
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The Solar-Radiant Heat-Reducing Effect of Silica/Clay Ceramic Covered with Moss 査読あり
Kentaro YASUI, Ayako TANAKA, Kenichi ITO, Minoru FUJISAKI, Hiroyuki KINOSHITA
Advanced Experimental Mechanics 4 179 - 185 2019年8月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Using mineral compositions to indicate the origin of sediments in a tidal flat of an estuarine marsh
Suzuki Y., Arao Y., Ito K., Yoshitake H., Hamaguchi K.
Coastal Engineering Journal 61 ( 3 ) 354 - 362 2019年7月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Coastal Engineering Journal
© 2019 Japan Society of Civil Engineers. Given the importance of tidal flats as habitats for a wide range of organisms, a considerable amount of related research has accumulated. However, in Japan, as elsewhere in the world, tidal flats are disappearing because of increasing seaside population, urbanization, and development of coastal industries. We investigated the sediment characteristics of Tsuyabaru Marsh in Japan, using X-ray fluorescence and X-ray diffraction (XRD) analyses to trace their sources. The estuarine Tsuyabaru Marsh comprises a tidal flat, the peripheral basin, the Ooyodo River, and the Yae River. The mineral components of the tidal flat sediment were quartz, mica minerals, kaolinite, plagioclase, and dolomite. To trace the sediment source and characterize the sediment in the Tsuyabaru Marsh, cluster analysis was applied to the peak XRD intensity ratios. A strong similarity was demonstrated between the sediments collected from the tidal flat and the Ooyodo River. A comparably strong similarity was found between sediments from the bottom of Tsuyabaru Marsh and the upstream Yae River section. Our analysis helps understand the sources and distribution of sediments in estuarine marshes.
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Yasui K., Tanaka A., Ito K., Fujisaki M., Kinoshita H.
Materials 11 ( 9 ) 2018年8月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Materials
© 2018 by the authors. To recycle silica byproducts and to moderate the heat-island phenomenon, a porous ceramic was prepared by mixing waste silica powder with clay, and then firing the resultant mixture. By exploiting the high water-absorption capacity of the resulting ceramic, a greening material in which the porous ceramic was covered with moss was produced. The suppression effect of the temperature increase caused by solar-radiant heat on the moss-covered ceramic, was investigated quantitatively using the following procedure. First, the surface temperature change of the water-absorbing moss-covered sample during solar-radiant heat reception, and the amount of water that evaporated from the sample were measured simultaneously. Then, the heat of evaporation was estimated from measurements of the rate of water evaporation. Next, to investigate how much the sample temperature was reduced by heat of water evaporation, the temperature change of the sample when the heat of water evaporation was absorbed from the sample, was simulated by performing Finite Element Method (FEM) analysis. The summary of the results was as follows. (1) The primary factor of the temperature-reduction-effects on the moss-covered sample was action of heat of water evaporation. Therefore, the moss-covered sample did not exhibit much of the suppression ability of the temperature increase caused by solar-radiant heat, when the sample did not contain sufficient water. (2) This analytical method enabled us to simulate with a relatively high accuracy, the temperature change of a water-absorbing sample during solar-radiant-heat reception. Especially, the method enabled us to investigate visibly the influence of water evaporation-heat on the sample temperature, in addition to the influences of the emissivity of the sample, and the apparent specific heat and thermal conductivity changes due to water content in the sample.
DOI： 10.3390/ma11091548
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廃シリカゲルを再利用したセラミック基盤を持つコケ緑化基盤材の開発 査読あり
田中 絢子, 安井 賢太郎, 伊藤 健一, 藤崎 稔, 木之下 広幸
宮崎大学工学部紀要 47 61 - 65 2018年7月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：宮崎大学工学部
To recycle silica byproducts and to moderate the heat-island phenomenon, a porous ceramic was prepared by mixing waste silica powder with clay and then firing the resultant mixture. The high water-absorption capacity of the ceramic was used to produce a greening material: a moss-covered porous ceramic. To examine the restraining ability of the temperature increase caused by solar-radiant heat on the moss-covered ceramic, the surface-temperature change of a moss-covered sample during solar-radiant-heat reception and the amount of water evaporated from the sample were measured simultaneously. To quantitatively investigate the influence of the water-evaporation heat on the temperature change of the moss-covered sample, the sample temperature change was simulated by performing a thermal-conductivity analysis and by considering the heat of evaporation using finite-element-methods analysis. The experimental results confirmed that the moss-covered sample that could absorb sufficient water could constrain the temperature increase caused by solar-radiant heat for a longer duration than the ceramic sample. The finite-elementsimulation results indicated that the restraining effect on the temperature increase by the moss-covered sample resulted from heat of water evaporation.