Knowledge Network Node
土壤圈(英文版). 2004, (01)

Preparative Parameter Effects on Synthesis of Birnessite by O2 OxidationEnglish Full Text

FENG Xiong-Han, ZU Yan-Qun, TAN Wen-Feng and LIU Fan 1 Key Laboratory of Subtropical Soil Resources and Environment, Chinese Agricultural Ministry, Huazhong Agricultural University, Wuhan 430070 (China). E-mail: fxh73@mail.hzau.edu.cn 2 College of Resources and Environment, Yunnan Agricultural University, Yunnan 650201 (China)

Abstract: Birnessite occurs in a wide variety of natural environments, and plays an important role in soil chemistry. A modified Stahli procedure was used to synthesize sodium birnessite in an alkali medium by O2 oxidation. The effects of preparative parameters on the synthesis of birnessite, such as pretreatment on solutions with N2, reaction temperature, O2, flow rate, fluxion velocity of the reaction suspension, and dehydration conditions were investigated. The fluxion velocity of the reactive suspension and O2 flow rate significantly influenced the synthesis of birnessite. Vigorous stirring raised the fluxion velocity of the reaction suspension and easily allowed synthesis of pure crystalline birnessite. However pretreatment of the reacting solutions with N2 and the reaction temperature had little effect on the synthesis. Diffusion of O2 was the controlling step during the course of oxidation. The optimum synthetic conditions for pure birnessite were: a NaOH to Mn molar ratio of 13.7, an O2 flow rate of 2 L min-1, and oxidation for 5 hours with vigorous stirring at normal temperatures. The chemical composition of the synthesized pure birnessite was Nao.25MnO2.07.0.66H2O.
Keywords：

birnessite; buserite; manganese oxide; preparative parameter; synthesis;

  • Series：

    (D) Agriculture

  • Subject：

    Fundamental Science of Agriculture; Agronomy

  • Classification Code：

    S153

  • Mobile Reading
    Read on your phone instantly
    Step 1

    Scan QR Codes

    "Mobile CNKI-CNKI Express" App

    Step 2

    Open“CNKI Express”

    and click the scan icon in the upper left corner of the homepage.

    Step 3

    Scan QR Codes

    Read this article on your phone.

  • HTML
  • CAJ Download
  • PDF Download

Download the mobile appuse the app to scan this coderead the article.

Tips: Please download CAJViewer to view CAJ format full text.

Download: 29 Page: 63-70 Pagecount: 8 Size: 479k

Related Literature
  • Similar Article
  • Reader Recommendation
  • Associated Author