Adsorption of Crystal Violet Dye from Aqueous Media by Algerian Clay: Studies on Equilibrium Isotherm, Kinetic and Thermodynamic of Interaction (original) (raw)
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Removal of Cationic Dye Methylene Blue from Aqueous Solution by Adsorption on Algerian Clay
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The objective of this study was to demonstrate the potential of Tiout-Naama (TN) clay for removing a cationic Methylene blue (MB) dye from aqueous solutions which was used for the first time like an adsorbent. For this, the effect of several parameters such as contact time, adsorbent dose, pH and temperature have been reported. Nearly 30 min of contact time are found to be sufficient for the adsorption to reach equilibrium. The residual concentration of the dye is determined using UV/Vis Spectrophotometer at wavelength 664 nm. Langmuir and Freundlich isotherm models were used to describe adsorption data. The result revealed that the adsorptions of MB dye onto TN clay is the best-fit both Langmuir and Freundlich isotherms, further to understand the adsorption kinetics the adsorption data were analyzed by the second-order and the pseudo-second-order. The results show that the methylene blue adsorption follows pseudo-second-order kinetics.
Water Resources and Industry, 2015
Inexpensive and easily available Moroccan natural clays were investigated for the removal availability of textile dyes from aqueous solution. For this purpose, the adsorption of methylene blue (MB) as reference molecule, malachite green (MG) representative of cationic dyes and methyl orange (MO) representative of anionic dyes, was studied in batch mode under various parameters. The clays were characterized by means of XRD, cationic exchange capacity and BET surface area analysis. The experimental results show that, the adsorption was pH dependent with a high adsorption capacity of MB and MG in basic range and high adsorption of MO in acidic range. The pseudo-second-order kinetic model provided the best fit to the experimental data for the adsorption of MB and MG by the clays. However, the adsorption of MO was more suitable to be controlled by an intra-particle diffusion mechanism. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The adsorption process was found to be exothermic in nature in the case of MB and MO. However, the adsorption of MG was endothermic.
Removal of methyl violet from aqueous solution using a stevensite-rich clay from Morocco
Applied Clay Science, 2011
An inexpensive and easily available Moroccan natural clay, called locally Ghassoul, was employed for adsorption of methyl violet, a cationic dye, in aqueous solution. The experiments were carried out in a batch system to optimize various experimental parameters such as pH, initial dye concentration, contact time, temperature and ionic strength. The experimental data can be well represented by Langmuir and Freundlich models. The Langmuir monolayer adsorption capacity was estimated as 625 mg/g at 298. Kinetic analyses showed that the adsorption rates were more accurately represented by a pseudo second-order model. Intraparticle diffusion process was identified as the main mechanism controlling the rate of the dye sorption. In addition, various thermodynamic activation parameters, such as Gibbs free energy, enthalpy, entropy and the activation energy were calculated. The adsorption process was found to be a spontaneous and endothermic process. The obtained results confirmed the applicability of this clay as an efficient and economical adsorbent for cationic dyes from contaminated water.
In this study, color removal by absorption from synthetically prepared wastewater was investigated using montmorillonite clay by adsorption. As dyestuff Astrazon Red Violet 3RN (Basic Violet 16) was used. Experimental parameters selected were pH, temperature, agitation speed, initial dyestuff concentration, adsorbent dosage and ionic strength. It was established that adsorption rate increased with increasing pH, temperature, dye concentration and agitation speed, but decreased with increased ionic strength and adsorbent dosage. Adsorption equilibrium data obtained by a series of experiments carried out in a water bath were employed with common isotherm equations such as Langmuir, Freundlich, Temkin, Elovich and Dubinin–Radushkevich. It was found that the Langmuir equation appears to fit the equilibrium data better than the other models. Furthermore, the fit of the kinetic data to common kinetic models such as the pseudo-first-order, second-order, Elovich and intraparticle diffusion models was tested to elucidate the adsorption mechanism. Kinetic data conformed to the pseudo-second-order model, indicating chemisorptions. In addition, the thermodynamic parameters activation energy, Ea, enthalpy ΔH*, entropy, ΔS*, and free energy change, ΔG*, were calculated. The values of the calculated parameters indicated that physical adsorption of ARV on the clay was dominant and that the adsorption process was endothermic.
Adsorption of textile dyes on raw Tunisian clay: Equilibrium, kinetics and thermodynamics
Journal of Advances in Chemistry, 2015
Natural clay from Nabeul region (north of Tunisia) was investigated for the removal of two anionic textile dyes (RR120 and BB150) from aqueous solution. The raw clay was characterized by means of XRD, IR spectroscopic, chemical analysis, cation exchange capacity and BET surface area analysis. Adsorption studies were carried out under various parameters such as pH, contact time, initial dye concentration and temperature. The adsorption kinetic data was tested by pseudo-first order, pseudo second-order and intra-particle diffusion kinetic models. The equilibrium data were analyzed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The thermodynamic parameters (H°, S° and G°) of the adsorption were also evaluated. The adsorption process was found spontaneous and endothermic in nature. The kinetics of adsorption were best described by pseudo-second order kinetic model. The Langmuir adsorption model totally agrees with the experimental data.
Removal of Basic Dyes from Aqueous Solutions by Adsorption onto Moroccan Clay (Fez City)
Mediterranean Journal of Chemistry, 2019
The main objective of this study was to investigate the potential of natural clay obtained from Fez city, Morocco) as an adsorbent for the removal of basic dyes (Astrazon Blue BG and Astrazon Yellow 7GLL) from liquid effluents. Natural clay was characterised using different physical-chemical methods, including nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), pH of the point of zero charge (pH PZC) and Boehm titration method. The clay was tested to remove various textile dyes from the aqueous solution at room temperature. Parameters such as initial dye concentration, solution pH, adsorbent dosages and contact time were performed in a batch system for controlling the operating conditions. Experimental results indicated that the adsorption process is a fast and spontaneous reaction. A pseudo-second-order kinetic model provides the best fit to the experimental data of BG and YL adsorption onto the natural clay. The adsorption isotherm data of both the dyes onto the natural clay were fitted well to the Langmuir model. A maximum monolayer adsorption capacity of 101 mg.g-1 for BG and 127 mg.g-1 for YL are obtained at 298.15 K. The results suggest that the natural clay could be used as an inexpensive adsorbent for the removal of the textile dyes from aqueous solutions.
Brazilian Journal of Chemical Engineering
In this study, color removal by absorption from synthetically prepared wastewater was investigated using montmorillonite clay by adsorption. As dyestuff Astrazon Red Violet 3RN (Basic Violet 16) was used. Experimental parameters selected were pH, temperature, agitation speed, initial dyestuff concentration, adsorbent dosage and ionic strength. It was established that adsorption rate increased with increasing pH, temperature, dye concentration and agitation speed, but decreased with increased ionic strength and adsorbent dosage. Adsorption equilibrium data obtained by a series of experiments carried out in a water bath were employed with common isotherm equations such as Langmuir, Freundlich, Temkin, Elovich and Dubinin-Radushkevich. It was found that the Langmuir equation appears to fit the equilibrium data better than the other models. Furthermore, the fit of the kinetic data to common kinetic models such as the pseudofirst-order, second-order, Elovich and intraparticle diffusion models was tested to elucidate the adsorption mechanism. Kinetic data conformed to the pseudo-second-order model, indicating chemisorptions. In addition, the thermodynamic parameters activation energy, Ea, enthalpy ΔH*, entropy, ΔS*, and free energy change, ΔG*, were calculated. The values of the calculated parameters indicated that physical adsorption of ARV on the clay was dominant and that the adsorption process was endothermic.
Clay Minerals
This work studied the efficiency of Tamazert kaolinite clay for adsorbing the cationic dye crystal violet from an aqueous solution in a batch system. The kinetics of the process and the equilibrium of adsorption were studied using non-linear models. The characterization of Tamazert kaolinite clay showed that it has structural, textural and surface properties that are suitable for adsorption. The effects of various process parameters such as contact time, initial dye concentration, initial pH, adsorbent dose and temperature were tested. The kinetic study using non-linear regression showed that the pseudo-second order model best fitted the experimental data. The intra-particle model was also used to estimate the contribution of intra-particle diffusion to this process. The adsorption isotherms were fitted to Freundlich, Langmuir and Redlich–Peterson models, showing that the adsorption is limited to a monolayer with a monolayer adsorption capacity of 44.2 mg g–1. The thermodynamic stud...
Mediterranean Journal of Chemistry, 2016
The adsorption capacity of two anionic textile dyes (RR120 and BB150) on DMSO intercalated Tunisian raw clay was investigated with respect to contact time, initial dye concentration, pH and Temperature. The equilibrium data were fitted into Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. The kinetic parameters were calculated using pseudo-first order, pseudo second-order, intra-particle diffusion and Elovich kinetic models. The thermodynamic parameters (H°, S° and G°) of the adsorption process were also evaluated.