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Hasan, Md. M.*; Janik, M.*; 迫田 晃弘; 飯本 武志*
Environmental Monitoring and Assessment, 193(12), p.770_1 - 770_10, 2021/12
被引用回数：2 パーセンタイル：12.7(Environmental Sciences)バングラデシュの全国調査に基づく推定で、自然バックグラウンド放射線からの被ばくによる潜在的に高いがんリスクが示された。自然バックグラウンドが高い地域では、土壌中のラジウムやトリウム含有量が世界平均よりも高かった。壊変生成物であるラドンの同位体は、これら地域に住む人々の肺への内部被ばくの環境リスク因子となりうる。肺がんは、バングラデシュで最も多く発生しているがんの一つだが、その現状や特徴はまだ明らかになっていない。本レビューでは、バングラデシュにおける肺がんの潜在的リスク因子の一つであるラドンの現状を明らかにするため、全国のラドン被ばくとその経路を地域別,住居別に把握することを目的とする。これによって、自然バックグラウンド放射線や土壌中の放射性核種濃度が高い地域における内部被ばくの状況を明らかにし、また、国内の肺がん有病率に対する環境ラドンの寄与を理解する。本レビューでは、バングラデシュの住居と職場における全国的な大気ラドンばく露について、査読付き論文をもとに整理した。バングラデシュにおけるラドンは、土壌からの散逸率が高いことから、有力な被ばく源の一つとして認識されている。バングラデシュの屋内および土壌中のラドン濃度をマップを用いて描くという新しい試みを行った。これは、今後の系統的なラドンや放射線学的調査や、同国の肺がんの有病率に関する研究の立案に役立つと考えられる。
Awual, M. R.; Hasan, M. M.*; Shahat, A.*; Naushad, M.*; 塩飽 秀啓; 矢板 毅
Chemical Engineering Journal, 265, p.210 - 218, 2015/04
被引用回数：261 パーセンタイル：99.36(Engineering, Environmental)In this study, the organic ligand of 4-dodecyl-6-((4-(hexyloxy)phenyl)diazenyl) benzene-1,3-diol (DPDB) and mesoporous silica have been used to prepare the nano-composite adsorbent. The nano-composite adsorbent was fabricated by indirect immobilization of DPDB onto the mesoporous silica. The experimental data clarified that the Ce(III) was detected and adsorbed by the adsorbent at pH 2.50. The limit of detection for Ce(III) ions by the adsorbent was 0.12 microgram/L and the sorption capacity was 150.37 mg/g at optimum conditions. The proposed adsorbent allowed the sensitive, selective, easy to use, cost-effective, high efficiency, fast kinetics and stable capturing of Ce(III) ions even in the presence of diverse competing ions.
Awual, M. R.; Hasan, M. M.*; Naushad, M.*; 塩飽 秀啓; 矢板 毅
Sensors and Actuators B; Chemical, 209, p.790 - 797, 2015/03
被引用回数：158 パーセンタイル：99.25(Chemistry, Analytical)In this study, we have developed S and N containing ligand of 5-tert-butyl-2-hydroxybenzaldehyde thiosemicarbazone. The organic ligand was anchored onto the mesoporous silica by an indirect method for the preparation of composite adsorbent. The adsorbent can detect Pd(II) ions at ultra-trace levels and recover the Pd(II) with high sorption capacity and efficiency. The adsorption isotherm data were well fitted with the Langmuir model, and the maximum sorption capacity of the composite adsorbent was 171.65 mg/g, which was close to the equilibrium sorption capacity.
Awual, M. R.; Hasan, M. M.*; Khaleque, M. A.*
Sensors and Actuators B; Chemical, 209, p.194 - 202, 2015/03
被引用回数：218 パーセンタイル：99.68(Chemistry, Analytical)Selenium occurs naturally in the environment and is toxic at elevated concentrations, which has been a challenging issue for environmental scientists. This work was devoted to the detection and removal the selenium (Se(IV)) from aqueous solutions using organic ligand an immobilized conjugate adsorbent. The organic ligand of (3-(3-(methoxycarbonyl) benzylidene)hydrazinyl) benzoic acid was synthesized and indirectly immobilized onto the mesoporous silica. The adsorbent was applied to detect and remove Se(IV) in aqueous solutions at optimum conditions. This adsorbent exhibited high surface area-to-volume ratios and pores were uniform nanostructures.
Awual, M. R.; Hasan, M. M.*; Znad, H.*
Chemical Engineering Journal, 259, p.611 - 619, 2015/01
被引用回数：259 パーセンタイル：99.35(Engineering, Environmental)The functional group containing organic ligand was developed and then successfully anchored onto mesoperous silica for the preparation of nano-conjugate adsorbent. After fabrication, the ligand kept open functionality for capturing Pd(II) under optimum conditions. The adsorbent exhibited the distinct color formation after adding the Pd(II) ions both in solid and liquid states. The base metal of Cu(II) and Zn(II) did not hamper the Pd(II) sorption ability of adsorbent in the acidic pH region. Therefore, it was expected that the Pd(II) could be separated from other hard metal ions by the adsorbent. Therefore the proposed adsorbent can be considered as a potential candidate for Pd(II) capturing from waste samples.
Awual, M. R.; Hasan, M. M.*
Journal of Industrial and Engineering Chemistry, 21, p.507 - 515, 2015/01
被引用回数：202 パーセンタイル：98.83(Chemistry, Multidisciplinary)A simple and sensitive method was applied for determination and extraction of trace level palladium(II) in wastewater by using functionalized mesoporous silica based fine tuning mesoporous adsorbent. The adsorbent was stable and easy to detect, adsorb and recover Pd(II) ions by charge transfer complexation mechanism. The optimum experimental conditions such as pH, contact time, initial concentration, selectivity and sensitivity, type and amount of eluent for elution and various ionic interferences on detection and sorption were systematically evaluated. The determined maximum sorption capacity was 191.35 mg/g. The proposed method was applied successfully for extraction of Pd(II) in environmental wastewater samples.
Awual, M. R.; Hasan, M. M.*
Sensors and Actuators B; Chemical, 206, p.692 - 700, 2015/01
被引用回数：223 パーセンタイル：99.69(Chemistry, Analytical)The nitrogen donor ligand was functionalized with polarable mesoporous silica as composite adsorbent, by a cost-effective and environmentally friendly procedure, for highly selective Cu(II) ions detection and removal from water. The composite adsorbent permitted fast and specific Cu(II) ions capturing via colorimetric naked eye detection based on stable complexation mechanism. The adsorbent was selective toward Cu(II) as shown by a light yellow to green color change. This was characterized by UVvis spectroscopy and the color change was observed for the visual detection of Cu(II) ions. The data also confirmed that the adsorbent is a cost-effective and environmentally friendly procedure for Cu(II) treatment.
Awual, M. R.; Hasan, M. M.*; Shahat, A.*
Sensors and Actuators B; Chemical, 203, p.854 - 863, 2014/11
被引用回数：176 パーセンタイル：99.19(Chemistry, Analytical)In this study, we designed ligand immobilized mesoporous adsorbent for ultra-trace Pb(II) monitoring and removal from wastewater. This adsorbent exhibited the large surface area-to-volume ratios and uniformly shaped pores in case cavities, and its active sites kept open functionality to taking up Pb(II). The data revealed that the adsorbent was able to detect the ultra-trace Pb(II) ions with high sensitivity and selectivity by charge transfer transduction mechanism. Then the adsorbent proved to have an efficient ability for continuous Pb(II) monitoring and removal even on-site and in situ chemical analyses.
Awual, M. R.; Hasan, M. M.*; 井原 敏博*; 矢板 毅
Microporous and Mesoporous Materials, 197, p.331 - 338, 2014/10
被引用回数：182 パーセンタイル：99.2(Chemistry, Applied)Selenium is a very toxic element that at low concentration can affect human beings and living organisms. In this study, the ligand immobilized conjugate adsorbent was developed and selenium (Se(IV)) detection and removal from water were investigated. The conjugate adsorbent was successfully prepared by direct immobilization of organic ligand onto mesoporous inorganic silica. This technique achieved residual Se(IV) concentration less than 10 ppb, which is acceptable by water quality regulations. Therefore, the solid design adsorbent is efficient and cost-effective for selective Se(IV) detection and removal from water.
Awual, M. R.; Hasan, M. M.*
Sensors and Actuators B; Chemical, 202, p.395 - 403, 2014/10
被引用回数：177 パーセンタイル：99.21(Chemistry, Analytical)The functionalized mesoporous silica based fine tuning meso adsorbent was developed for ultra trace lead (Pb(II)) detection and removal from wastewater. The design of the ligand into ordered pore based meso adsorbent transformed the Pb(II) detection and removal systems into smart and stable assemblies. The ability of the meso adsorbent to detect and remove Pb(II) from aqueous solutions has been studied and discussed with different optimized conditions of concentrations, the amount of meso adsorbent, concentration of coexisting electrolyte and pH. The design of such a tunable meso adsorbent offered a simple procedure in such toxic Pb(II) ions removal without using high tech, sophisticated instruments.
Awual, M. R.; Hasan, M. M.*
Microporous and Mesoporous Materials, 196, p.261 - 269, 2014/09
被引用回数：223 パーセンタイル：99.57(Chemistry, Applied)Lead (Pb(II)) is a very toxic heavy metal that even at low concentration can affect living organisms. Therefore, designing effective materials with high selectivity and cost efficiency is essential for the control capturing of toxic Pb(II) ions. This study developed a ligand based conjugate adsorbent for simultaneous Pb(II) detection and removal from water samples. The experiment conditions were optimized based on contact time, solution acidity, initial Pb(II) concentration and pH value and diverse metal salt concentrations. The presence of other cations and anions did not adversely affect the Pb(II) capturing by the adsorbent. The maximum sorption capacity was determined to be as high as 195.31 mg/g.
迫田 晃弘; Hasan, Md. M.*; 神崎 訓枝; 飯本 武志*
no journal, ,
ラドンは自然界に存在する放射性ガスであり、肺がんの原因となりうる。屋内ラドン濃度について、過去数十年の間に日本を含む多くの国や地域で調査が行われ、国際的な報告書にまとめられている。国民の線量評価に向けた年間ラドン濃度は、長期的な積算測定に基づいて決定される。一方、屋内ラドン濃度の空間的・時間的変動や上昇のメカニズムを解明したり、短期・中期の測定値からの年平均値の予測可能性を検討するために、ラドンや関連する環境因子を高時間分解能で連続測定する取り組みも行われている。本研究では、これら測定結果に係る知見を収集・更新し、今後の課題を検討した。
迫田 晃弘; Hasan, Md. M.*; 飯本 武志*
no journal, ,
屋内ラドン(
Rn)の主な発生源には土壌や建材が考えられ、それぞれのラドン散逸の特性について、これまでにin-situ測定や実験室でのサンプル測定によって調査されてきた。本研究で着目する建材については、その先行研究の多くは管理された環境条件下でのサンプル測定に基づくもので、in-situ測定による実証例は乏しかった。本発表では、1年間以上にわたり実施した、建物内壁からのラドン散逸率のin-situ測定の結果を報告する。
迫田 晃弘; 石森 有; Hasan, Md. M.*; Jin, Q.*; 神崎 訓枝; 飯本 武志*
no journal, ,
レンガやコンクリートなどの建材は、屋内ラドン(Rn-222)やトロン(Rn-220)の線源のひとつであることが知られている。ラドンやトロン散逸について、これまでの研究の多くは建材の破片やブロックを用いた実験室試験に基づいてきた。本研究では、実験室で得られた知見を実環境でどのように適用できるかを明らかにするため、集合住宅の一室において、異なる構造の壁(一枚壁、空洞壁)に対して、1年以上にわたってラドンおよびトロン散逸率のin-situ測定を実施した。本研究によって、屋内ラドンおよびトロン濃度の時空間変化をモデリングする際に必要な線源情報(入力パラメータ)に関する知見が深まった。
