Comparative and Competitive Study of LDH/Diatomite and Chitosan/Diatomite for Adsorptive Removal of Chloride Ion from Aqueous Solution | ||
| Journal of Mining and Environment | ||
| مقاله 17، دوره 11، شماره 1، فروردین 2020، صفحه 261-279 اصل مقاله (4.89 M) | ||
| نوع مقاله: Original Research Paper | ||
| شناسه دیجیتال (DOI): 10.22044/jme.2020.9023.1789 | ||
| نویسندگان | ||
| F. Sadough Abbasian1؛ B. Rezai* 2؛ A. R. Azadmehr2؛ H. Hamidian3 | ||
| 1Department of Mining Engineering ,Science And Research Branch,Islamic Azad University,Tehran,Iran | ||
| 2Department of Mining and Metallurgical Eng. Amirkabir University of Technology, Tehran, Iran | ||
| 3Department of Mining Engineering, Qaem Shahr Branch Islamic Azad University, Qaem Shahr, Iran | ||
| چکیده | ||
| In this work, two clay-based composites are prepared for the adsorptive removal of the chloride ions from aqueous solutions. These composites are characterized through Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray fluorescence spectroscopy, and X-ray diffraction analysis. The effects of different parameters such as the contact time, amount of adsorbent, chloride concentration, temperature, and pH are studied by batch experiments. Also the isotherm, kinetic, and thermodynamic of the adsorptive removal of the chloride ions from these two composites are investigated. According to the results obtained, the adsorptive removal of chloride ions is initially rapid, and the equilibrium time is reached after 30 min. The optimal pH value is 7.0 for a better adsorption, and the maximum capacity can be achieved, which is 60.2 mg/g with 1000 mg/L of the initial chloride concentration. The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption models are applied to describe the equilibrium isotherms at different chloride concentrations. According to the equilibrium isotherms and the correlation coefficients (R2CDC: 0.9424, R2LDC: 0.996), the process can be described by the Langmuir model, and exhibits the highest removal rate of 97.24% (24.31 mg/g) with 250 mg/L of the initial chloride concentration. The pseudo-first-order and pseudo-second-order, intra-particle diffusion, and mass transfer kinetics models are used to identify the mechanism of the adsorptive removal of the chloride ions. The pseudo-second order model due the correlation coefficients (R2CDC: 0.9217-0.9852, R2LDC: 0.9227-0.9926) can be fitted to the kinetic calculations, and it is applicable for the adsorptive removal of chloride ions by the adsorbents. The thermodynamic calculations show that in a low chloride concentration, the sorption is spontaneous, associative, and endothermic; and in a high concentration, it is unspontaneous, dissociative, and endothermic. The calculated value of free energy (E) for adsorption onto the adsorbents suggests that the reaction rate controls the adsorptive removal of the chloride process rather than diffusion. It can be concluded that these two composites can be used as effective and applicable adsorbents for the adsorptive removal of chloride ions. | ||
| کلیدواژهها | ||
| Adsorption؛ Wastewater؛ Chloride؛ Anion exchange؛ Diatomite | ||
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آمار تعداد مشاهده مقاله: 946 تعداد دریافت فایل اصل مقاله: 984 |
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