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Removal of Cr(VI) from aqueous environments using micelle-clay adsorption.

Qurie M, Khamis M, Manassra A, Ayyad I, Nir S, Scrano L, Bufo SA, Karaman R - ScientificWorldJournal (2013)

Bottom Line: Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions.Langmuir adsorption isotherm fitted the experimental data giving significant results.The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Chemical Technology, Faculty of Science and Technology, Al-Quds University, 20002 Jerusalem, Palestine ; Department of Science, University of Basilicata, Via dell'Ateneo Lucano 10, 85100 Potenza, Italy.

ABSTRACT
Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.

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Langmuir isotherm plot for the adsorption of Cr(VI) into the micelle-clay complex. Contact time = 3 h, temperature = 25.0 ± 0.2°C, and adsorbent dosage = 5.0 g L−1. Data represent averages of Cr(VI) triplicate measurements (UV-vis) ± SE.
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fig6: Langmuir isotherm plot for the adsorption of Cr(VI) into the micelle-clay complex. Contact time = 3 h, temperature = 25.0 ± 0.2°C, and adsorbent dosage = 5.0 g L−1. Data represent averages of Cr(VI) triplicate measurements (UV-vis) ± SE.

Mentions: In order to selectively investigate the adsorption isotherm for Cr(VI), we analyzed the equilibrium concentration (Ce) of Cr(VI) using the UV-vis method. Figure 6 displays the Langmuir isotherm plotted using new Ce data. In this case, the linearity of the isotherm was maintained within the full range of equilibrium concentrations measured. The Langmuir constants Qmax⁡ and k were calculated from the new slope and the intercept of (1) obtaining values of 2.84 mg g−1 and 0.176 L mg−1, respectively. The new value of Qmax⁡ was lower than that obtained determining Ce as total-Cr values. This result confirms that micelle-clay system was catalyzing the reduction of adsorbed Cr(VI) to Cr(III) and then the release of the last species to solution. In any case, micelle clay complex showed the highest maximum adsorption capacity compared to other low cost adsorbents.


Removal of Cr(VI) from aqueous environments using micelle-clay adsorption.

Qurie M, Khamis M, Manassra A, Ayyad I, Nir S, Scrano L, Bufo SA, Karaman R - ScientificWorldJournal (2013)

Langmuir isotherm plot for the adsorption of Cr(VI) into the micelle-clay complex. Contact time = 3 h, temperature = 25.0 ± 0.2°C, and adsorbent dosage = 5.0 g L−1. Data represent averages of Cr(VI) triplicate measurements (UV-vis) ± SE.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814082&req=5

fig6: Langmuir isotherm plot for the adsorption of Cr(VI) into the micelle-clay complex. Contact time = 3 h, temperature = 25.0 ± 0.2°C, and adsorbent dosage = 5.0 g L−1. Data represent averages of Cr(VI) triplicate measurements (UV-vis) ± SE.
Mentions: In order to selectively investigate the adsorption isotherm for Cr(VI), we analyzed the equilibrium concentration (Ce) of Cr(VI) using the UV-vis method. Figure 6 displays the Langmuir isotherm plotted using new Ce data. In this case, the linearity of the isotherm was maintained within the full range of equilibrium concentrations measured. The Langmuir constants Qmax⁡ and k were calculated from the new slope and the intercept of (1) obtaining values of 2.84 mg g−1 and 0.176 L mg−1, respectively. The new value of Qmax⁡ was lower than that obtained determining Ce as total-Cr values. This result confirms that micelle-clay system was catalyzing the reduction of adsorbed Cr(VI) to Cr(III) and then the release of the last species to solution. In any case, micelle clay complex showed the highest maximum adsorption capacity compared to other low cost adsorbents.

Bottom Line: Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions.Langmuir adsorption isotherm fitted the experimental data giving significant results.The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Chemical Technology, Faculty of Science and Technology, Al-Quds University, 20002 Jerusalem, Palestine ; Department of Science, University of Basilicata, Via dell'Ateneo Lucano 10, 85100 Potenza, Italy.

ABSTRACT
Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.

Show MeSH
Related in: MedlinePlus