報告書番号

V04013

タイトル（和文）

排水中微量元素の吸着処理プロセスの開発（その２） --多孔質ジルコニウム吸着剤の吸脱着特性評価--

タイトル（英文）

Development of adsorption process for trace elements in wastewaters (Part 2)Adsorption-desorption properties for trace elecments over the porous zirconium material

概要 （図表や脚注は「報告書全文」に掲載しております）

水中の微量陰イオンに対して高い吸着能を示す多孔質ジルコニウム化合物（Zr-S）について，最適再生条件と吸脱着特性を明らかにした。(1)Zr-Sへの陰イオンの吸着は，Zr-S表面の硫酸イオンとの陰イオン交換によって進行することがわかったため，Zr-Sの再生溶液として硫酸イオンを含む水溶液を選定した。濃度の異なる４種の硫酸溶液および1M硫酸ナトリウム溶液を用いた結果，0.1 M硫酸溶液が最も効率的にZr-Sを再生することがわかった。(2)吸着実験後のZr-Sの重量は試験前の60%程度に低下した。Zr-Sは調製時に細孔構造を形成する鋳型として使用した界面活性剤を50 wt.%含有した。吸着・再生実験でのZr-Sの重量減少分の70～80%は，Zr-Sからの界面活性剤の溶出に起因した。

概要 （英文）

The porous zirconium material which is referred to as Zr-S is effective for removing aqueous trace anions in wastewaters, e.g., boron, fluorine, arsenic and selenium. In this study, effective solutions for regenerating spent Zr-S were investigated. Adsorption-desorption properties over Zr-S were also investigated. The results are summarized as follows:(1) Fixation of the anions into Zr-S is considered to Adsorption of the anions on Zr-S is considered to proceed through the ion exchange with surface sulfuric acid ions on Zr-S. Thus, sulfuric acid solutions with different concentrations and a 1M solution of sodium sulfate were employed to regenerate the spent Zr-S. A solution of 0.1 M sulfuric acid was found to be the most favorable for the regeneration of Zr-S since it yielded the maximum recovery of boron with no zirconium elution from Zr-S. In the adsorption-regeneration cycles of boron, boric anion and surfuric anion were reversely exchanged with each other in Zr-S, which was confirmed by FTIR observation. (2) Zr-S is reduced to roughly 60% in weight after the adsorption test. Based on the elemental analysis, Zr-S was found to have the sufactant at 50 wt.%, which was used as a template to build pore structure during its hydrothermal synthesis. The weihgt loss of 70-80% observed between before and after the adsorption tests, were attributed to elution of the surfactant from Zr-S and the ion exchange on Zr-S.

報告者

キーワード