Elucidation of Zn surface complexation and precipitation mechanism in coprecipitation with birnessite

DOI

Bibliographic Information

Other Title
  • バーネス鉱(δ-MnO2)共沈系におけるZn表面錯体形成と表面沈殿機構の解明

Description

<p>Birnessite (δ-MnO2) is recognized as an adsorbent for heavy metal ions in soil and aqueous environments. In particular, coexisting metal ions can be incorporated into the crystalline structure of δ-MnO2 when δ-MnO2 is formed under a high Mn oxidation rate. Thus; in this research we studied the mechanism of Zn coprecipitation and the surface complexation associated with the formation of δ-MnO2 under neutral pH conditions (pH 6.0, and pH7.5), considering the results of surface complex modeling and X-ray absorption fine structure (XAFS) analysis. As a result, the coprecipitation mechanism was estimated as the three-dimensional uptake of Zn accompanying the formation of Zn-Mn minerals on the surface of δ-MnO2, in addition to the surface complexation with Zn between the layers of δ-MnO2. In addition, the produced Zn-Mn minerals differed depending on the pH and Zn/Mn molar ratio, and a large difference was confirmed in the amount adsorbed. From the XAFS analysis, it is considered that this could be caused by the transformation of the mineral composition and crystal structure by a slight difference in pH change.</p>

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Keywords

Details 詳細情報について

  • CRID
    1390008918664284672
  • NII Article ID
    130008129814
  • DOI
    10.14862/geochemproc.68.0_19
  • Text Lang
    ja
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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