Sorption and thermodynamic behavior of zinc(II)-thiocyanate complexes onto polyurethane foam from acidic solutions

  • S. M. Hasany
  • M. M. Saeed
  • M. Ahmed
Article

Abstract

The uptake of Zn(II)-SCN complex onto polyurethane foam (PUF) has been investigated in detail with respect to different composition and variable concentration of electrolyte, zinc, thiocyanate ions and PUF, and equilibration time. The sorption data followed both Langmuir and Dubinin-Radushkevich (D-R) sorption isotherms over the entire concentration range of zinc investigated whereas Freundlich sorption isotherm is obeyed upto 13.6.10-3M concentration. The Langmuir constants Q = 202±7 mmole.g-1 and of b = (1.78±0.31.104 dm3.mole-1 and of D-R paraneter Xm = 493±1 mmole.g-1, b = activity coefficient = -0.028±0.0002 and of sorption energy E = 13.2±0.5 kJ.mole-1 and Freundlich constants 1/n = 0.42±0.03 and cm = 6.47±1.7 mmole.g-1 were evaluated. The influence of temperature variation on sorption have yielded DH = -77.5±2.9 kJ.mole-1, DS = -5±0.09 J.mole-1.K-1 and DG = -6.67±0.05 kJ.mole-1. The effect of common anions and cations on the sorption has been examined. Sulphate, ascorbate and bromide ions enhances the sorption to some extent whereas nitrite, Pb(II), Fe(III), Al(III), Cu(II) and Co(II) decrease to sorption significantly. A possible mechanism has been envisaged for Zn(II)-SCN sorption onto PUF.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    M. GRAYSON, Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., Vol. 24, John Wiley & Sons, New York, 1984.Google Scholar
  2. 2.
    C. H. G. SEILER, H. SIGEL, A. SIGEL, Handbook on Toxicity of Inorganic Compounds, Marcel Dekker, Inc., New York, 1988.Google Scholar
  3. 3.
    V. PAKAREK, V. VESELY, Talanta, 19 (1972) 217; 1245.Google Scholar
  4. 4.
    A. CLEARFIELD (Ed.), Inorganic Ion-Exchange Materials, CRC Press Inc., Boca Raton, Florida, USA, 1982.Google Scholar
  5. 5.
    Z. B. ALFASSI, C. M. WAI (Eds), Preconcentration Techniques for Trace Elements, CRC Press, Boca Raton, Florida, USA, 1992.Google Scholar
  6. 6.
    S. M. HASANY, F. A. CHUGHTAI, A. GHAFFAR, Separ. Sci. Technol., 26 (1991) 1131.Google Scholar
  7. 7.
    T. BRAUN, J. D. NAVRATIL, A. B. FARAG, Polyurethane Foam Sorbent in Separation Science, CRC Press, Boca Raton, Florida, USA, 1985.Google Scholar
  8. 8.
    M. M. SAEED, S. M. HASANY, M. AHMED, Talanta, 50 (1999) 625.Google Scholar
  9. 9.
    S. M. HASANY, M. M. SAEED, M. AHMED, Separ. Sci. Technol., 35 (2000) 379.Google Scholar
  10. 10.
    S. M. HASANY, M. M. SAEED, M. AHMED, Separ. Sci. Technol., 36 (2001).Google Scholar
  11. 11.
    A. CHOW, S. G. GINSBERG, Talanta, 30 (1983) 620.Google Scholar
  12. 12.
    I. LANGMUIR, J. Am. Chem. Soc., 40 (1918) 136.Google Scholar
  13. 13.
    M. M. DUBININ, L. V. RADUSHKEVICH, Proc. Acad. Sci. USSR, Phys. Chem. Sect., 55 (1947) 331.Google Scholar
  14. 14.
    M. POLANYI, Trans. Faraday Soc., 28 (1932) 316.Google Scholar
  15. 15.
    B. P. BERING, M. M. DUBININ, V. V. SERPENSKII, J. Colloid Interface Sci., 38 (1972) 185.Google Scholar
  16. 16.
    H. FREUNDLICH, Colloid and Capillary Chemistry, Methuen, London, 1926.Google Scholar
  17. 17.
    R. SIPS, J. Chem. Phys., 16 (1948) 690.Google Scholar
  18. 18.
    A. E. MARTELL, L. G. SILLEN, Stability Constants of Metal ion Complexes, Spec. Publ. No. 25, The Chemical Society, London, 1971.Google Scholar
  19. 19.
    A. T. TROTMAN DICKENSON (Executive Ed.), Comprehensive Inorganic Chemistry, 1st ed., Longmans Press, Oxford, 1973, p. 216.Google Scholar
  20. 20.
    F. HELFFREICH, Ion Exchange, McGraw Hill, New York, 1962, p. 166.Google Scholar
  21. 21.
    R. F. HAMON, A. CHOW, Talanta, 31 (1984) 963.Google Scholar
  22. 22.
    A. AKSOYOGLU, J. Radioanal. Nucl. Chem., 140 (1990) 301.Google Scholar
  23. 23.
    T. SEKINE, Y. HASEGAWA, Solvent Extraction Chemistry, Marcel Dekker Inc., New York, 1977, p. 272 and references therein.Google Scholar
  24. 24.
    R. F. HAMON, A. S. KHAN, A. CHOW, Talanta, 29 (1982) 313.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • S. M. Hasany
    • 1
  • M. M. Saeed
    • 1
  • M. Ahmed
    • 1
  1. 1.Nuclear Chemistry DivisionPakistan Institute of Nuclear Science and TechnologyIslamabadPakistan

Personalised recommendations