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| 1.
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論文
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Maki, Teruya ; Hara, Kazutaka ; Kobayashi, Fumihisa ; Kurosaki, Yasunori ; Kakikawa, Makiko ; Matsuki, Atsushi ; Chen, Bin ; Shi, Guangyu ; Hasegawa, Hiroshi ; Iwasaka, Yasunobu
概要:
Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and
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can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere. © 2015 Elsevier Ltd. All rights reserved.<br />Embargo Period 24 months
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| 2.
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論文
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Sawai, Hikaru ; Rahman, Ismail M.M. ; Tsukagoshi, Yoshinori ; Wakabayashi, Tomoya ; Maki, Teruya ; Mizutanai, Satoshi ; Hasegawa, Hiroshi
概要:
Non-ferrous smelting dust, especially lead-smelting dust (LSD), contains percent levels of indium and thus constitutes a
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novel indium resource. The main difficulty in recovering indium from LSD is the coexisting presence of lead and zinc. In this study, a unique indium separation process was designed, combining techniques that involve washing with a chelant, leaching with acid and precipitation as hydroxide. The majority of the Pb in the LSD was selectively separated during chelant-assisted washing with ethylenediaminedisuccinate (EDDS), while the residual Pb was diminished through an acid leaching treatment with a mixed solution of sulfuric acid and hydrochloric acid. The chelant washing step also ensures a decrease in the raw LSD weight at a ratio of approximately 82% due to the removal of lead and counterions such as sulfate, and the washing step also minimizes the consumption of corrosive acids in the subsequent step. Selective indium separation from LSD is further complicated by the similarity of the behavior of zinc during the acid leaching step. Therefore, hydroxide precipitation at pH 5 has been introduced as the final step, ensuring the maintenance of zinc as a soluble species in the supernatant and the selective separation of indium (~88%) as a hydroxide precipitate. © 2015 Elsevier B.V.<br />Embargo Period 48mouths
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| 3.
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論文
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Maki, Teruya ; Hara, Kazutaka ; Kobayashi, Fumihisa ; Kurosaki, Yasunori ; Kakikawa, Makiko ; Matsuki, Atsushi ; Bin, Chen ; Shi, Guangyu ; Hasegawa, Hiroshi ; Iwasaka, Yasunobu
概要:
Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and
…
can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere. © 2015 Elsevier Ltd. All rights reserved.<br />Embargo Period 24 months
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| 4.
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論文
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Begum, Zinnat A. ; Rahman, Ismail M. M. ; Sawai, Hikaru ; Hasegawa, Hiroshi
概要:
The immobilization or removal of toxic components using aqueous extractants, with or without additives, is one of the co
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mmonly practiced techniques for the treatment of metal-contaminated soils. However, rather than the use of water alone, the solution with chemical-additives is preferred due to the less time requirement and better separation effectiveness. There is a long-favored list of additives that have been used for the chemical-induced washing remediation of soils, which include acids, bases, chelants, surfactants, and so forth. The objective of this chapter is to provide a brief overview of the chemical-assisted soil washing approaches. © Springer Japan 2016. All rights are reserved.<br />[Book Chapter]
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| 5.
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Rahman, M. Azizur ; Reichman, Suzie M. ; Filippis, Luigi De ; Sany, Seyedeh Belin Tavakoly ; Hasegawa, Hiroshi
概要:
Over centuries, industrial, mining and military activities, agriculture, farming, and waste practices have contaminated
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soils and wetlands in many countries with high concentrations of toxic metals. In addition to their negative effects on ecosystems and other natural resources, toxic metals pose a great danger to human health. Unlike organic compounds, metals cannot be degraded, and clean-up usually requires their removal. Most of the conventional remedial methods have lost economic favor and public acceptance because they are expensive and cause degradation of soil fertility that subsequently results in adverse impacts on the ecosystem. Conventional methods of environmental remediation do not solve the problem; rather they merely transfer it to future generation. Obviously, there is an urgent need for alternative, cheap, and efficient methods to clean-up sites contaminated with toxic metals. Phytoremediation, a plant-based green technology, is cost effective, environmental friendly, aesthetically pleasing approach for the remediation of toxic metals. Due to its elegance and the extent of contaminated areas, phytoremediation approaches have already received significant scientific and commercial attention. Two approaches have been proposed for the phytoremediation of toxic metals from soils and wetlands: natural and induced phytoremediation. Natural phytoremediation refers to the use of hyper-accumulating plants and associated soil microbes, while the induced phytoremediation refers to the use chemicals, especially synthetic chelating ligands, for the increase of metal bioavailability and uptake in plants. Recently, genetically modified plants (GMPs) have been proposed to use in phytoremediation technology; however, this approach is being hindered by ideology-driven restrictive legislation over the use of GMPs. We will discuss the concepts and practical applications of phytoremediation technologies for the restoration of contaminated soils and wetlands. © Springer Japan 2016. All rights are reserved.<br />[Book Chapter]
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