Adsorptive removal of Cr(VI) from aqueous solutions with an effective adsorbent: cross-linked chitosan/montmorillonite nanocomposites in the presence of hydroxy-aluminum oligomeric cations

Abstract

2015):Adsorptive removal of Cr(VI) from aqueous solutions with an effective adsorbent: cross-linked chitosan/montmorillonite nanocomposites in the presence of hydroxy-aluminum oligomeric cations, Desalination and Water Treatment, A B S T R A C TOn the basis of laboratory research, the adsorbent of cross-linked chitosan/Al 13 -pillared montmorillonite (CCPM) was examined on the removal of Cr(VI) from aqueous solutions. In order to determine the effects of process parameters namely cross-linked chitosan-to-clay ratio, temperature, initial solution pH, initial Cr(VI) concentration, adsorbent dose, and contact time on Cr(VI) uptake, batch studies were systematically conducted. Equilibrium data were applied to the Langmuir and Freundlich isotherm models and best described by the Langmuir isotherm model. It was shown that monolayer adsorption capacity was 15.67 mg/g of Cr(VI) obtained by the Langmuir isotherm model. The kinetics of adsorption correlated well with the pseudo-second-order equation. Moreover, the intra-particle diffusion model was applied to investigate the mechanism of adsorption. Furthermore, thermodynamic parameters including free energy change, enthalpy change, and entropy change revealed that the adsorption of Cr(VI) onto CCPM was endothermic and spontaneous. The results suggest that CCPM is an effective adsorbent for removing Cr(VI) ions from aqueous solutions.

Evaluation of TiO2/smectite nanoparticles as an alternative low-cost adsorbent for chromium removal from industrial wastewater

“…The chromium adsorption was described by Langmuir isotherm and intraparticle diffusion model. Wang et al [41] prepared chitosan-Al-pillared montmorillonite nanocomposite to remove Cr(VI). They reported that the maximum adsorption capacity of chromium was 15.68 mg/g for pH 6.38 and ambient temperature.…”

Clay-Polymer Nanocomposites: Preparations and Utilization for Pollutants Removal

“…Efforts have been conducted to remove the toxic heavy metals from water using clay as the support and chitosan as the polymer [ 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 ]. Divalent copper ions were removed from water using chitosan–silver NPs clay composite with a maximum adsorption capacity (181.6 mg/g) at pH 7 [ 94 ].…”

“…In the same context, Chitosan–Al-pillared montmorillonite nanocomposite was used to remove Cr (VI) with an adsorption capacity of 15.68 mg/g [ 97 ]. Lead and copper divalent ions were removed with a similar nanocomposite prepared with clay: chitosan ratio of 1:0.45 to remove Pb (II) and Cu (II) at pH 6.5 with an efficiency of 99.5% and 96%, respectively via chemisorption mechanism.…”