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Journal of Chemistry
Volume 2013, Article ID 427586, 10 pages
Research Article

Use of Forestry Wastes for Biosorption of Dyes and Cr (VI)

Department of Chemistry, Faculty of Science, Ege University, Bornova, 35100 Izmir, Turkey

Received 4 June 2012; Revised 3 September 2012; Accepted 25 September 2012

Academic Editor: Shayessteh Dadfarnia

Copyright © 2013 Nariye Berraksu 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.


The pine cone and oak cups pulp were used as low-cost adsorbents for the removal of basic (Basic Red 18) and acidic (Acid Red 111) dyes and Cr (VI) from aqueous solutions. The adsorbents were modified by HNO3 to improve their biosorption capacity. The adsorbents were characterized using scanning electron microscopy and FTIR spectroscopy. The zeta potential was determined as a function of the pH, in order to explain the effect of pH on electrostatic adsorption ability of biosorbent. Modification of adsorbents with nitric acid led to an increase in accessibility of some functional groups on the surface or a decrease in negativity of surface charge. The modification of pine cone increased its adsorption capacity for the basic dye, whereas the modification of oak cups pulp decreased the adsorption ability for basic dye to some extent. The adsorption isotherms fitted the Langmuir model. The adsorption capacities were found to be 142.85, 158.73, and 156.20 mg g-1 for modified and raw pine cone and oak cups pulp, respectively. The acidic dye and Cr (VI) adsorptions were much lower compared to basic dye on all tested adsorbents. The results indicated that the forest wastes (pine cone and oak cups pulp) were an attractive candidate for basic dyes from aqueous solution.