• ISSN 1008-505X
  • CN 11-3996/S
涂仕华, G.J.Racz, . 水钠锰矿(Birnessite)对Mn2+持留机理的研究[J]. 植物营养与肥料学报, 1994, 1(1): 90-97. DOI: 10.11674/zwyf.1994.0112
引用本文: 涂仕华, G.J.Racz, . 水钠锰矿(Birnessite)对Mn2+持留机理的研究[J]. 植物营养与肥料学报, 1994, 1(1): 90-97. DOI: 10.11674/zwyf.1994.0112
Shihua Tu G. J. RaczSichuan Academy of Agricultural Sciences, University of Manitoba, Canada. MECHANISM OF ADSORPTION OF Mn2+ ONTO A SYNTHETIC BIRNESSITE[J]. Journal of Plant Nutrition and Fertilizers, 1994, 1(1): 90-97. DOI: 10.11674/zwyf.1994.0112
Citation: Shihua Tu G. J. RaczSichuan Academy of Agricultural Sciences, University of Manitoba, Canada. MECHANISM OF ADSORPTION OF Mn2+ ONTO A SYNTHETIC BIRNESSITE[J]. Journal of Plant Nutrition and Fertilizers, 1994, 1(1): 90-97. DOI: 10.11674/zwyf.1994.0112

水钠锰矿(Birnessite)对Mn2+持留机理的研究

MECHANISM OF ADSORPTION OF Mn2+ ONTO A SYNTHETIC BIRNESSITE

  • 摘要: 本试验研究了一种合成水钠锰矿对Mn2+的持留机理和Mn2+被吸附后的去向,并进一步探讨了三种锰盐溶液(MnSO4,MN(NO3)2和MnCl2)对水钠锰矿晶体结构变化的影响。.试验结果表明,水钠锰矿对MN2+离子的吸附包括专性吸附和非专性吸附。随着吸附后的老化过程,吸附在矿物表面的锰逐渐扩散到晶格内,其置换性随之降低。.在MnSO4,Mn(NO3)2和MnCl2溶液中,水钠锰矿最终转化成六方锰矿(Nsutite),一种比水钠锰矿更稳定,结晶更好的晶体。MnSO4溶液在加入水钠锰矿后pH值比其它两种溶液高,除生成六方锰矿外还形成大量拉锰矿(Ramsdellite)。随着生成新矿物的老化,最初被吸附的Mn被固定在晶格内而失去其置换性和生物有效性。

     

    Abstract: Adsorption of Mn2+ onto birnessite is very rapid and amounts adsorbed are several times higher than its cation exchange capacity. The nature and fate of the adsorption, however, were not well understood. Thus experiments were conducted to investigate the mechanism of adsorption of Mn2+ onto a synthetic birnessite and effects of three Mn-salts (MnSO4, MnCl2 and Mn(NO3)2) on mineralogical alteration of birnessite.The results indicated that adsorption of Mn2+ onto birnessite included both specific and non specific adsorption. The adsorbed Mn2+ was incorporated into the structure of birnessite and its extrability by salts decreased with time of aging. After reaction of birnessite with MnCl2 or Mn (NO3)2 solution, incorporation of Mn2+ into he structure caused transformation of birnessite into nsutite (Mn oxide hydroxide, -Mn (O, OH)2). In the solution of MnSO4, birnessite was convened into nsutite and a larger quantity of ramsdellite (Mn oxide, MnO2) . Both newly formed minerals are more stable and better crystallized than birnessite. Thus the Mn2+ initially adsorbed onto birnessite became the component of the newly formed minerals and was fixed in the structure after structural conversion of birnessite and finally lost its extractability and availability.

     

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