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SORBENTS OF HEAVY METALS BASED ON COMBINATION OF LOW RANK COALS AND CHITOSAN
Abstract
The study has been aimed at development of cheap sorbents of toxic heavy metals and radionuclides based on low rank, low energetic coals in combination with chitosan for use in treatment of both waste and drinking water and construction of active geochemical barriers. Sorbents based on lignite and naturally oxidized lignite (oxihumolite, leonardite) were prepared, both raw and impregnated with chitosan from its solution in oxalic acid. The sorbents were characterized by chemical and structural analyses. Their sorption performance for Co, Cu, and Cd was tested in equilibrium sorption experiments with respect to pH and metal concentration. The sorption efficiencies were calculated from the amount of metal retained by the sorbent, which was determined by instrumental neutron activation analysis in the short time irradiation mode with epithermal neutrons (in a Cd shielding). For pH 5, sorption isotherms were determined and fitted using the Langmuir-Freundlich model. Although chitosan provides only surface coating of the coal sorbents, its presence has affected significantly their sorption performance. At identical pH values, the sorption efficiencies of the chitosan coated coals were higher than those of the raw coals for Co and Cd, and this difference was increasing with pH. For Cu, the effect was ambiguous and rather reverse. The chitosan coating may stabilize coal in basic solution and inhibits leaching of humic substances and their complexes with the metals from coal into solution. Besides fixing metal humates within the sorbents, chitosan may positively affect the sorption efficiency also by its buffering action against the hydroxide addition.
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References4
Mizera J., Mizerová G., Machovic V., Borecká L. Sorption of cesium, cobalt and europium on low-rank coal and chitosan. Water Res., 41, pp 620-626, 2007.
Randa Z., Soukal L., Mizera J. Possibilities of the short-term thermal and epithermal neutron activation for analysis of macromycetes (mushrooms). J. Radioanal. Nucí. Chem., 264, pp 67-76, 2005.
Rhazi M., Desbrieres J., Tolaimate ?., Rinaudo M., Vottero P., Alagui A., El Meray M. Influence of the nature of the metal ions on the complexation with chitosan. Application to the treatment of liquid waste. Eur. Polym. J., 38, pp 1523-1530, 2002.
Havelcová M, Mizera J, Sykorová I, Pekaf M. Sorption of metal ions on lignite and the derived humic substances. J. Hazard. Mater., 161, pp 559-564, 2009.
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