M. Massoud; M. Erhayem; F. Al-Tohami
Abstract
In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic ...
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In the present study, batch adsorption experiments of hazardous cadmium ions, Cd(II), onto low-cost Dodonaeae Viscose Legs (DVLs) surface were conducted with respect to contact time, solution pH, adsorbent dosage, initial Cd concentration and temperature. Sorption isotherm, kinetic and thermodynamic models were used to describe the equilibrium stage and their constants were determined. The DVLs were used without chemical or physical activation processes. The results showed that the optimum adsorption capacity of DVLs for Cd(II) ions was found to be 25.29 mg/g at solution pH 5.26, 50 min and 303K. DVL adsorption data was fitted well with Langmuir isotherm. The mean free energy was found to be 1.82E-02 using Dubinin-Radushkevich (DRK) isotherm, which indicates that the adsorption of Cd(II) ions onto DVL surface is physical adsorption. The activation energy (Ea) was 3.06 kJ/mol, which confirms that Cd(II)-DVL adsorption process is physical sorption. Pseudo-first-order, pseudo-second-order, Elovich, intra-particle and extra-particle diffusion models were used to describe the adsorption kinetics. The results show strong correspondence to a pseudo-second-order kinetics. Thermodynamic parameters suggested that the adsorption of Cd(II) ions onto DVL surface is an exothermic process.
I. A. Amar; A. Sharif; M. M. Alkhayali; M. A. Jabji; F. Altohami; M. A. Abdul Qadir; M. M. Ahwidi
Abstract
In this study, the adsorption properties of spinel ferrite-based adsorbent, CoFe1.9Mo0.1O4 (CFMo), for removal of methylene blue (MB) from aqueous solution have been investigated. Sol-gel process was successfully employed to prepare CoFe1.9Mo0.1O4 magnetic nanoparticles. The synthesized adsorbent was ...
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In this study, the adsorption properties of spinel ferrite-based adsorbent, CoFe1.9Mo0.1O4 (CFMo), for removal of methylene blue (MB) from aqueous solution have been investigated. Sol-gel process was successfully employed to prepare CoFe1.9Mo0.1O4 magnetic nanoparticles. The synthesized adsorbent was characterized by Fourier transform infrared (FTIR), scanning electron microscope (SEM) and X-ray diffraction (XRD). The adsorption experiments were carried out at various operational conditions (solution pH, initial dye concentration, contact time, adsorbent dosage and temperature) to evaluate the potential adsorption property of CFMo magnetic nanoparticles. The results showed that, under the optimum adsorption parameters, approximately 95 % of MB dye can be removed. The adsorption data were better described by Langmuir isotherm model and the maximum amount of MB adsorbed was about 20.45 mg/g. Several adsorption kinetic models and thermodynamic parameters (∆Gº, ∆Hº, ∆Sº) were used to fit the adsorption experimental data. The adsorption kinetics followed the pseudo-second-order model (PSO), while the thermodynamic parameters indicate that the proposed adsorption process was endothermic and spontaneous in nature. The obtained results suggest that CFMo is promising adsorbent material for removal of very toxic dyes from aqueous solutions.