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Arsenic In Geothermal Systems
http://hdl.handle.net/10458/6264
http://hdl.handle.net/10458/626460da17eb-3619-4ab3-b2e2-830ca19d3f04
| 名前 / ファイル | ライセンス | アクション |
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本文 (61.8 kB)
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| Item type | その他 / Others(1) | |||||
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| 公開日 | 2020-06-21 | |||||
| タイトル | ||||||
| タイトル | Arsenic In Geothermal Systems | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| キーワード | ||||||
| 言語 | en | |||||
| 主題Scheme | Other | |||||
| 主題 | Arsenic, geothermal environment | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_1843 | |||||
| 資源タイプ | other | |||||
| 著者 |
Chelo, S. Pascua
× Chelo, S. Pascua |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The geothermal environment is a geochemically dynamic environment where the variations in pH, redox and temperature greatly affect the stability of aqueous ligands present. Arsenic complexes dominance and stabilities are greatly in fluenced by these physicochemical variations, and thus their affinity with mineralogical hosts. In the study areas in Japan and the Philippines, amorphous silica and a smectite were found to uptake arsenic stably. Their resistance to rigorous leaching in either highly alkaline or highly acidic solution suggests that they must be structurally incorporated, especially in the smectite found in Japan. X -ray spectroscopy has further shown that the arsenic is dominantly in the form of AS^llI-O species and only minor contributions from both As^V-O and As^lll-S forms. The potential of the clay to uptake arsenic was further investigated in synthesis experiments designed to determine the mechanism involved. Both co-precipitation with smectites through initial Aslll-Si complexation, and sorption to precursory poorly crystalline phyllosilicates was able to uptake arsenic in large amounts and offers significant stability. Despite difficulties in characterizing the poorly crystalline synthesized phyllosilicates, the timing of arsenic uptake based on co-precipitation and sorption experiments provide insights on the possible crystallographic location of arsenic in the phyllosilicate structure. Arsenic uptake through initial complexation with dissolved silica would suggest incorporation into the tetrahedral structure, and would also support its affinity with amorphous silica in the natural environment. Initial adsoption with a poorly crystalline phyllosilicate and later incorporation would more favorably enable it to substitute into octahedral sites （i.e. Mg2+） rather than the tetrahedral sites. In both cases of uptake, it is implied that arsenic can go into the phyllosilicate structure with the in situ formed mineralogical hosts similar to the documented arsenic-bearing smectite. |
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| 言語 | en | |||||
| 書誌情報 |
en : 4th InternationalArsenic Symposium in MIYAZAKI 2015 p. 16-19, 発行日 2015-10 |
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| 出版者 | ||||||
| 出版者 | University of Miyazaki, IRISH | |||||
| 言語 | en | |||||
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| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
