Chitosan selectivity for removing cadmium (II), copper (II), and lead (II) from aqueous phase: pH and organic matter effect

Adsorption of reactive black 5 (RB5) from aqueous solution onto chitosan was investigated in a batch system. The effects of solution pH, initial dye concentration, and temperature were studied. Adsorption data obtained from different batch experiments were modeled using both pseudo first-and second-order kinetic equations. The equilibrium adsorption data were fitted to the Freundlich, Tempkin, and Langmuir isotherms over a dye concentration range of 45-100 mmol/L. The best results were achieved with the pseudo second-order kinetic and Langmuir isotherm equilibrium models, respectively. The equilibrium adsorption capacity (q e ) was increased with increasing the initial dye concentration and solution temperature, and decreasing solution pH. The chitosan flakes for the adsorption of the dye was regenerated efficiently through the alkaline solution and was then reused for dye removal. The activation energy (E a ) of sorption kinetics was estimated to be 13.88 kJ/mol. Thermodynamic parameters such as changes in free energy (DG), enthalpy (DH), and entropy (DS) were evaluated by applying the van't Hoff equation. The thermodynamics of reactive dye adsorption by chitosan indicates its spontaneous and endothermic nature.

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Section: Introductionmentioning

confidence: 99%

Adsorption Characteristics of Reactive Black 5 from Aqueous Solution onto Chitosan

Saha

Bhoumik

Karmaker

et al. 2011

CLEAN Soil Air Water

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“…This is the most abundant biopolymer in nature after cellulose. The high proportions of amino functions in chitosan have been found to provide novel adsorption properties for many metal ions (Chu 2002;Rangel-Mendez et al 2009) and organic dyes (Modak et al 2009;Lazaridis et al 2007;Chiou and Li 2002). The deacetylated amino groups in chitosan can be protonated and the polycationic properties of the polymer are expected to contribute to the charged interactions with a model dye, remazol red RR (RRR), which is an anionic azo dye (Fig.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of remazol red RR onto chitosan from aqueous solution

Kabir

Islam

Masum

et al. 2015

Bangladesh J. Sci. Ind. Res.

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Chitosan has been used as an adsorbent to remove remazol red RR from aqueous solution by adsorption. The experiments have been conducted to study the effects of initial concentration of adsorbate, temperature, pH and particle size on dye adsorption. The kinetic data obtained have been examined using pseudo first-and pseudo second-order equations. The equilibrium adsorption data have been studied by using Freundlich and Langmuir models. The best results have been achieved with the pseudo second-order kinetic model and with the Langmuir equilibrium isotherm model. The equilibrium adsorption capacity (q e ) of chitosan increases with increasing the initial concentration of dye, temperature and with decreasing particle size. However, the highest adsorption capacity has been found at a pH about 5.4. The maximum monolayer adsorption capacity, q e = 155.72 mg/g has been found at the optimum conditions. The activation energy (E a ) of sorption kinetics is about 9.25 kJ/mol. Thermodynamic parameters such as change in free energy (∆G), enthalpy (∆H) and entropy (∆S) have also been evaluated.

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“…However, these methods have some limitations due to their high operational costs and/or their possible inefficiency in the removal of some toxic metal ions, mainly at trace level concentrations (Reddad et al 2002;Rangel-Mendez et al 2009). Among these methods, adsorption is considered to be an effective and economical process for removing pollutants from wastewater (Wan Ngah et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Copper(II) and Mercury(II) Ions onto Chemically-Modified Chitosan Membranes: Equilibrium and Kinetic Properties

Rabelo

Vieira

Luna

et al. 2012

Adsorption Science & Technology

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Cross-linked chitosan was synthesized with glutaraldehyde (chitosan-GLA) and epichlorohydrin (chitosan-ECH). The structures of these matrices were characterized by elemental analysis, Fourier-transform infrared spectrometry (FT-IR), the degree of de-acetylation and the surface topography as determined via scanning electron microscopy (SEM). After promoting interaction with the metal ion, the adsorbent was also studied using FT-IR and energy dispersive X-ray spectroscopy (EDXS). Adsorption studies for Cu(II) and Hg(II) ions were carried out in a batch process. The adsorption kinetics were tested using three models, viz. pseudo-first-order, pseudo-second-order and intra-particle diffusion. The experimental kinetic data were best fitted by the pseudo-second-order model for Cu(II) ions (R 2 ≥ 0.98) and for Hg(II) ions (R 2 = 0.99). Higher rate constants (k 2 ) were obtained for the adsorption of Cu(II) ions onto chitosan-GLA [1.40 g/(mmol h)] and for Hg(II) ions onto raw chitosan [5.65 g/(mmol h)]. The adsorption rate depended on the concentration of Cu(II) and Hg(II) ions on the adsorbent surface and on the quantity of ions adsorbed at equilibrium. At 293 K, the Langmuir-Freundlich model provided a better fit to the adsorption isotherms on both raw and cross-linked chitosan membranes. The maximum adsorption capacity for Cu(II) ions was obtained with the chitosan-GLA matrix (2.7 mmol/g). A maximum adsorption capacity of 3.1 mmol/g was attained for Hg(II) ions onto the chitosan-ECH matrix.

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Chitosan selectivity for removing cadmium (II), copper (II), and lead (II) from aqueous phase: pH and organic matter effect

Cited by 161 publications

References 10 publications

Adsorption Characteristics of Reactive Black 5 from Aqueous Solution onto Chitosan

Adsorption Characteristics of Reactive Black 5 from Aqueous Solution onto Chitosan

Adsorption of remazol red RR onto chitosan from aqueous solution

Adsorption of Copper(II) and Mercury(II) Ions onto Chemically-Modified Chitosan Membranes: Equilibrium and Kinetic Properties

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