著者

杉田 創 駒井 武 沖田 伸介 徳永 修三 松永 烈

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.121, no.9, pp.416-422, 2005 (Released:2007-02-24)

参考文献数

20

被引用文献数

3 3

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For the purpose of examining the adsorption behavior of fluorine on clay minerals, the adsorption equilibrium experiments on fluorine were carried out using several clay minerals. Then various analysis and considerations, as listed in the followings, were done on the basis of the experimental results.1) The adsorbed amount of fluorine per unit mass of clay mineral was ranged as Kaolinite >Saponite >Pyrophyllite, Dickite >Montmorillonite.2) When the mass ratio of clay mineral to liquid was constant, the ratio of adsorption equilibrium concentration of fluorine to initial one became small, as the initial concentration of fluorine was lower.3) It was clear that there was less correlation between the BET specific surface area of the clay minerals and the adsorbed amount of fluorine, because the BET specific surface area was ranged as Saponite > Montmorillonite(Mikawa) > Kaolinite > Montmorillonite(Tsukinuno)> Dickite > Pyrophyllite. 4) The cations such as the alkali metal (Na, K), alkaline earth metal (Ca, Mg), iron, silicon and aluminum, which are contained in the clay minerals, are major chemical components which may be bonded with fluorine. However the quantitative correlation between those each content in the clay minerals and the absorbed amount fluorine could not be recognized. 5) For each clay mineral, the fluorine adsorption data can be arranged clearly in every conditions for the mass ratio of clay mineral to liquid. It was clarified the adsorption isotherm of fluorine on the clay minerals were represented using Freundlich's adsorption equation. 6) The correlation equations which took the mass ratio of clay mineral to liquid into consideration were proposed on the adsorption coefficient and index in Freundlich's adsorption equation. Using both those equations and the values of adsorption parameters obtained in this study, it becomes possible to estimate the adsorbed amount of fluorine on the clay minerals and fluorine concentration in liquid phase.

著者

中村 謙吾 肴倉 宏史 川辺 能成 駒井 武

出版者

公益社団法人 土木学会

雑誌

土木学会論文集G(環境) (ISSN:21856648)

巻号頁・発行日

vol.71, no.1, pp.39-48, 2015 (Released:2015-02-20)

参考文献数

24

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製鋼スラグの利用用途で,腐植物質との混合による磯焼け回復技術が注目されているが,製鋼スラグから溶出する重金属等の環境影響を検討する必要がある.本研究では純水による検討に加えて,海域利用を想定し,実海水を用いて振とう試験および浸漬式のシリアルバッチ試験を実施した.さらに,海域利用において要求される環境安全品質の考え方に基づき,海域利用への適合性について考察を行った.試験結果より,Cd,Pb,Cr,Bは,試験条件を変えた場合に,溶出濃度が港湾用途溶出量基準を超過することは確認されず,製鋼スラグ及び腐植物質の相互作用により,重金属類の溶出濃度は減少傾向を示した.また,本研究で想定した海域利用の環境安全品質を設定し,本試験結果を適用した結果,重金属類による海域汚染の原因となる可能性は低いことが示唆された.

著者

杉田 創 駒井 武

出版者

公益社団法人 日本地下水学会

雑誌

地下水学会誌 (ISSN:09134182)

巻号頁・発行日

vol.62, no.4, pp.573-587, 2020

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<p>石油系炭化水素を対象とした発光バクテリアを用いた簡易土壌汚染評価手法の開発を目的として,既往の研究においてガソリン等の主要な構成成分であるn-アルカンの急性毒性影響が調べられた。しかしながら,ガソリン等多くの石油系炭化水素製品には分岐アルカンも多く含まれている。本研究では,試験対象物質としてアルカン構造異性体であるペンタンの構造異性体2種類及びヘキサンの構造異性体5種類に加えて環状アルカンであるシクロヘキサンを用い,分子構造による発光バクテリアに及ぼす急性毒性影響の差異の有無を調べた。メタノールに溶解したアルカン構造異性体を検液とした試験における急性毒性影響の強さは,反応時間60分での相対発光強度比が50%となるアルカン濃度の推測値を基準にすると,2-メチルブタン<n-ペンタン<2,2-ジメチルブタン<シクロヘキサン<3-メチルペンタン≦2,3-ジメチルブタン≦2-メチルペンタン<n-ヘキサンであった。構造異性体間の試験結果の比較から,分岐アルカンよりも直鎖アルカンの方が発光バクテリアに対して強い急性毒性影響を持つと評価された。加えて,直鎖部分の炭素数が多い物質ほど急性毒性影響が強いことが示唆された。</p>

著者

駒井 武

出版者

公益社団法人 日本地下水学会

雑誌

地下水学会誌 (ISSN:09134182)

巻号頁・発行日

vol.61, no.1, pp.47-54, 2019-02-28 (Released:2019-09-12)

参考文献数

13

被引用文献数

2 1

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東日本沿岸における津波堆積物の性状と地球化学的特性を中心に,津波堆積物に含有する重金属類や塩分の組成について表層土壌や海底堆積物と比較した結果について述べた。また,現場調査の結果として得られた各種分析データを用いてリスク評価を行い,地下水および土壌環境への影響について考察し,津波堆積物のリスク管理の在り方について検討した。津波堆積物では土壌と比べて砒素および鉛の含有量,溶出量が高く,地下水飲用の制限等が必要な場合もあった。一方,多くの場合では,所定のリスク管理を実施した後に津波堆積物を復興資材として活用可能であることが分かった。

著者

中村 謙吾 佐藤 海里 川辺 能成 桑谷 立 駒井 武

出版者

一般社団法人 資源・素材学会

雑誌

日本鑛業會誌 (ISSN:18816118)

巻号頁・発行日

vol.132, no.1, pp.22-30, 2016

被引用文献数

2

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It is important to understand the distribution mechanism of heavy metal elements in environmental systems, because the toxicities of various metals and metalloids significantly affect health risks. The heavy metals concentrations are controlled by a wide of variety environmental factors. This study aims to clarify main influence factors on the heavy metal distribution in sediment, soil, river in the Natori River, Sendai City. We firstly produced geochemical maps for heavy metal concentrations (As, Pb and Cr) of river sediment, neighboring soil (bulk component, soluble component in 1N HCl and in pure water) and river water. The heavy metals concentrations in river water increase from upper stream to down stream, whereas heavy metal concentrations in river sediments and soil vary little from upper stream to downstream. There are no anomalous distributions of heavy metals in the studied area, although many anthropogenic materials are found in sediment, soil and river water. The correspondence analysis was applied to investigate relationships of heavy-metal concentrations between sediment, soil and river water. The results indicate that the heavy metals (As, Pb Cr and Zn) in sediment, soil and river water are dominantly controlled by natural sedimentary processes, such as denudation and sedimentation. The proposed method could be further applied for other pollutants in various environment systems. From a viewpoint of risk assessment of heavy metals, it is suggested by the presence of closer relationship of heavy metals that contains the risk information of heavy metals.

著者

桑谷 立 岡本 敦 吉田 健太 中村 謙吾 土屋 範芳 駒井 武

出版者

日本地球惑星科学連合

雑誌

日本地球惑星科学連合2018年大会

巻号頁・発行日

2018-03-14

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The high-dimensional and large amounts of data sets in geosciences show very complex behavior and often have large uncertainty. It is important to extract a small number of essential parameters which can explain the phenomenon from high-dimensional data in order to understand the behavior of dynamic solid earth. Under the framework of a big scientific project entitled as “Initiative for high-dimensional data-driven science through deepening sparse modelling” supported by the MEXT in Japan ( http://sparse-modeling.jp/index_e.html ), we try to introduce data-driven approaches into geosciences. In this presentation, we will share some applications in solid-earth science and discuss future prospects.

著者

中村 謙吾 桑谷 立 駒井 武 山崎 慎一

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.134, no.2, pp.13-21, 2018-02-01 (Released:2018-02-15)

参考文献数

36

被引用文献数

4

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Understanding the geochemical characteristics of various soils is significant for revealing the mechanisms occurring under natural conditions, assessing the environmental risks and managing the land use. However these various soils have complex forming mechanisms. This study examined geochemical characteristics of surface soils using statistical analysis. Principal component analysis (PCA), a very commonly used multivariate technique that can extract hidden structures and patterns from high-dimensional data, was applied to 633 classified soil samples. Soil samples collected in the Miyagi and Ibaraki prefectures were analyzed for major elements (Si, Ti, Al, Fe, Mg, Mn, Ca, Na and K) and heavy metals (Cr, Cu, Zn, As and Pb). Major elements showed most distinctive relationships with an inverse correlation between Si and Ti, Fe and Al. Heavy metals did not exhibit clear correlations with each other. However, background concentrations could be estimated using the frequency distribution and log-normal distribution curves. The background concentration of Cr, Cu, Zn, As and Pb were 50 ~150 mg/kg, 75 ~150 mg/kg, 200 ~300 mg/kg, 25 ~50 mg/kg and 30 ~60 mg/kg, respectively. Results of PCA clarified four common factors controlling major elements and heavy metals in the soil samples. They are ‘Physicochemical formation', ‘Soil components',‘ Vegetation effect' and ‘Adsorption and desorption'. Soils are formed by leaching reactions from rain and groundwater and mixed organic matter from different vegetation types. Therefore, major elements and heavy metals in soil are affected by these processes, which are common to most soil types.