Adsorption studies on fruits of Gular (Ficus glomerata): removal of Cr(VI) from synthetic wastewater.
ABSTRACT The adsorption of Cr(VI) was studied in batch system using fruits of Ficus glomerata as adsorbent. The effect of temperature, pH, initial Cr(VI) concentration and time was investigated. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate surface morphology and active functional groups present on the adsorbent surface. Thermodynamic parameters like free energy change (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) indicate the spontaneous, endothermic and increased randomness nature of Cr(VI) adsorption. Equilibrium data were fitted well with Langmuir isotherm at 50 degrees C. The magnitude of mean free energy indicates chemical nature of adsorption. The breakthrough and exhaustive capacities were found to be 5 and 23.1 mg g(-1) respectively. The applicability of the adsorbent has been demonstrated by removing Cr(VI) from electroplating wastewater.
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ABSTRACT: In the present study, a heterogeneous adsorbent material (HA) was used as an adsorbent for the removal of Cr(VI) from aqueous solutions at laboratory scale. Cr(VI) containing was treated with heterogeneous adsorbent(HA).Chromium solutions of various initial concentrations were treated with adsorbent in batch mode experiments to investigate the adsorption characteristics of heterogeneous adsorbent(HA). Kinetics of adsorption of Cr(VI) ions on adsorbent was investigated by using pseudo first order and second order kinetic models. Removal processes was found to be governed by pseudo second order model. Intraparticle diffusion model was also analyzed for this system. Removal was found to be increased by increasing temperature from 298 to 318K which indicates the endothermic nature of process. Various two parameter isotherm models viz. Langmuir, Freundlich, Elovich, Tempkin, Dubnin-Raduskevich (D-R), Harkin-Jura and BET isotherm were applied on resultant data for equilibrium modeling. It was observed that heterogeneous adsorbent (HA) particles were highly efficient for the removal of Cr(VI).Arabian Journal of Chemistry 11/2013; · 2.68 Impact Factor
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ABSTRACT: In this investigation a waste biological material, soybean meal, was applied as a biosorbent for heavy metal ions (CrIII). The diffusive Webber-Morris model and the pseudo-II-order model suitably described the kinetics of CrIII ions binding on soybean meal. The Langmuir-Freundlich equation was valid for the description of the isotherm. Inductively coupled plasma optical emission spectroscopy (ICP-OES), FTIR and scanning electron microscopy with an energy dispersive X-ray analytical system (SEM-EDX) were used in order to identify the mechanism of the metal ions binding. The analysis of the composition of the enriched soybean meal confirmed the contribution of ion exchange in the biosorption process. Three-variable-three-level Box-Behnken design was used to determine the optimal conditions for biosorption of CrIII on soybean meal. The optimal conditions for predicted maximum Cr3+ uptake (61.07 mg g−1) by soybean meal were estimated by Matlab and established as temperature of 38.04°C, initial metal concentration 500 mg L−1 and biosorbent dosage 1 g L−1. Graphical abstractCentral European Journal of Chemistry 11(9). · 1.33 Impact Factor
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ABSTRACT: While numerous investigations have examined microstructural, substructural and damage evolution due to shock loading, few of these studies have directly linked substructural evolution as a function of crystallographic orientation with nucleation of damage during shock loading. In this work, quantitative characterization of damage and substructural evolution in bicrystal copper reveals that the density of dislocation cells based on activation of available slip systems due to Schmid factor analysis influences damage nucleation in copper.Scripta Materialia - SCRIPTA MATER. 01/2011; 65(12):1069-1072.