%0 Journal Article
%T Removal of Azo Dyes (Violet B and Violet 5R) from Aqueous Solution Using New Activated Carbon Developed from Orange Peel
%A Saeedeh Hashemian
%A Khaterah Salari
%A Hamila Salehifar
%A Zahra Atashi Yazdi
%J Journal of Chemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/283274
%X Activated carbon developed from agricultural waste orange peel (COP) was prepared. COP was characterized using Fourier infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and BET. COP has surface area and mean pore diameter of 225.6£¿m2£¿g£¿1 and 22.40£¿nm, respectively. The removal of violet B (VB) and violet 5R (V5R) from aqueous solutions by COP was investigated. The effect of operational parameters such as contact time, pH, initial dye concentration, and adsorbent dosage on the adsorption of dyes was investigated. Maximum dye was removed within 30 min of contact time at pH > 7. Two common models, the Langmuir and Freundlich isotherms, were used to investigate the interaction of dye and COPs. The isotherm evaluations revealed that the Langmuir model provides better fit to the experimental data than the Freundlich model. The adsorption of VB and V5R onto COP was followed by pseudo-second-order kinetic model with a good correlation ( ). Activation energies 5.47 and 29.7£¿KJ£¿mol£¿1 were determined for violet B and violet 5R, respectively. The rate of adsorption of violet 5R was faster than that of violet B ( ). The prepared COP could thus be used as promising adsorbent for removal of organic dyes, especially azo dye, from polluted water. The solid COP could be conveniently regenerated after adsorption. 1. Introduction Many industries employ dyes and pigments to color their products. Most dyes are inert and nontoxic at the concentration discharged into the receiving water. Dyes are usually stable to photodegradation, biodegradation, and oxidizing agents [1]. Color removal from effluents is a major environmental problem because of difficulty of treating such streams by conventional physicochemical and biological treatment methods [2]. Many physical and chemical methods such as coagulation, precipitation, and oxidation have been used for dye removal from water [3]. Adsorption has been described in order to eliminate or lower concentration of a wide range of dissolved pollutants (organic or inorganic) in the effluent [4]. Dye removal by different sorbents was evaluated [5, 6]. Activated carbon is the most widely used adsorbent for this purpose. It has high capacity for adsorption of organic maters, but its uses are limited, because of its high cost [7, 8]. This has led to search for cheaper sorbents such as mineral clays [9¨C12], sawdust [13¨C16], and so on. Recently, various kinds of activated carbon have been achieved from different agriculture wastes and used as low-cost sorbents for removal of heavy metals, organic
%U http://www.hindawi.com/journals/jchem/2013/283274/