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Bioinorganic Chemistry and Applications
Volume 2010, Article ID 457964, 8 pages
Research Article

Biofunctional Characteristics of Lignite Fly Ash Modified by Humates: A New Soil Conditioner

1Inorganic Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis, 157 71 Athens, Greece
2School of Chemical Engineering, National Technical University of Athens, 9 Heroon Polytechniou, Zografou Campus, 157 73 Athens, Greece

Received 29 December 2009; Accepted 2 March 2010

Academic Editor: Spyros Perlepes

Copyright © 2010 Konstantinos Chassapis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Fly ash superficially modified with humic substances from the Megalopolis lignitic power plant was prepared and evaluated for agricultural uses. UV-vis spectrophotometry and IR spectroscopy revealed that fly ash shows high sorption efficiency towards humic substances. Adsorption proceeds stepwise via strong Coulombic and hydrophophic forces of attraction between guest and host materials. Langmuir, Freundlich, BET, Harkins-Jura, and Dubinin-Radushkevich isotherm models were employed to evaluate the ongoing adsorption and shed light to the physicochemical properties of the sorbent-adsorbate system. Humic substances desorption and microbial cultivation experiments were also carried out to examine the regeneration of the humates under washing and explore the possibility of this material acclimatizing in real soil conditions, both useful for biofunctional agricultural applications.