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Dehydration, Diffusion and Entrapment of Zinc in Bentonite

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Clays and Clay Minerals

Abstract

Interactions with bentonite are important in the chemical speciation and fate of heavy metals in soils and other ecosystems. The interactions of Zn with bentonite were studied using X-ray diffraction (XRD), dehydration, kinetic and sequential extraction procedures. The species and activity of Zn retained by bentonite were affected markedly by pH. The Zn(OH)+ was retained by bentonite prepared at pH ≥ 6.9. The extent of dehydration of Zn(OH)+-bentonite was higher than that for Zn-bentonite. At a relative humidity of 55.5%, the basal spacing of the Zn(OH)+-bentonite was from 1.21 to 1.26 nm with 1 water sheet and that of the Zn-bentonite was 1.51 nm with 2 water sheets. The greater affinity of Zn(OH)+ for bentonite than Zn was associated with a lower degree of hydration. When an aqueous suspension of Ca-bentonite was incubated with soluble Zn, the concentration of Zn retained by the Ca-bentonite was linearly related to the square root of time. The rate of the interaction was controlled probably by the interlayer diffusion and subsequently by the diffusion into the ditrigonal cavities in bentonite. The Zn retained by bentonite was dehydrated in situ so as to increase the bonding of Zn with surfaces of bentonite. With hydrothermal treatment the retained Zn could diffuse easily into the cavities and transform increasingly to the residual forms that are associated with the entrapped form.

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References

  • Bain DC, Smith BFL. 1994. Chemical analysis. In: Wilson MJ, ed. Clay mineralogy: Spectroscopic and chemical determinative methods. London. Chapman & Hall, p 300–332.

    Chapter  Google Scholar 

  • Ben Hadj-Amara A, Besson G, Tchoubar C. 1987. Caractéristiques structurales d’une smectite dioctaèdrique en fonction de Tordre-désordre dans la distribution des charges électriques: Études des reflexions 001: Clay Miner 22:305–318.

    Article  Google Scholar 

  • Calvet R, Prost R. 1971. Cation migration into empty octahedral sites and surface properties of clays. Clays Clay Miner 19:175–186.

    Article  Google Scholar 

  • Crank J. 1975. The Mathematics of diffusion. Oxford Univ Pr. 414 p.

    Google Scholar 

  • Denis JH, Keall MJ, Hall PL, Meeten GH. 1991. Influence of potassium concentration on the swelling and compaction of mixed (Na, K) ion-exchanged montmorillonite. Clay Miner 26:255–268.

    Article  Google Scholar 

  • Dixon JB, Weed SB. 1989. Minerals in soil environments (2nd ed). Madison, WI: Soil Sci Soc Am 1244 p.

    Google Scholar 

  • Farmer VC. 1978. Water on particle surfaces. In: Greenland DJ, Hayes MHB, eds. The Chemistry of soil constituents. New York: J. Wiley, p 405–448.

    Google Scholar 

  • Farrah H, Pickering WF. 1976. The sorption of zinc species by clay minerals. Aust J Chem 29:1649–1656.

    Article  Google Scholar 

  • Frenkel M. 1974. Surface acidity of montmorillonites. Clays Clay Miner 22:435–441.

    Article  Google Scholar 

  • Koryta J, Dvorák J. 1987. Principles of electrochemistry. Great Britain: J. Wiley. 447 p.

    Book  Google Scholar 

  • Luca V, Cardile CM. 1989. Cation migration in smectite minerals: Electron spin resonance of exchanged Fe3+ probes. Clays Clay Miner 37:325–332.

    Article  Google Scholar 

  • Newman ACD, Brown G. 1987. The chemical constitution of clays. In: Newman ACD, ed. Chemistry of clays and clay minerals. London Mineral Soc. London: Longman. p 1–128.

    Google Scholar 

  • Pass G. 1973. Ions in solution (3): Inorganic properties. Oxford: Clarendon Pr. 101 p.

    Google Scholar 

  • Quirk JP, Posner AM. 1975. Trace element adsorption on mineral surfaces. In: Nicholas DJD, Egan AR, eds. Trace elements in soil-plant-animal systems. New York: Academic Pr. p 95–107.

    Chapter  Google Scholar 

  • Reddy MR, Perkins HE 1974. Fixation of zinc by clay minerals. Soil Sci Soc Am Proc 38:229–231.

    Article  Google Scholar 

  • Tan KH. 1993. Principles of soil chemistry (2nd ed). New York: Marcel Dekker. 362 p.

    Google Scholar 

  • Tiller KG, Gerth J, Bruemmer G. 1984. The relative affinity of Cd, Ni and Zn for different soil clay fractions and goe-thite. Geoderma 34:17–35.

    Article  Google Scholar 

  • Tiller KG, Hodgson JE 1962. The specific sorption of cobalt and zinc by layer silicates. Clays Clay Miner 9:393–403.

    Article  Google Scholar 

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Ma, Y.B., Uren, N.C. Dehydration, Diffusion and Entrapment of Zinc in Bentonite. Clays Clay Miner. 46, 132–138 (1998). https://doi.org/10.1346/CCMN.1998.0460202

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  • DOI: https://doi.org/10.1346/CCMN.1998.0460202

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