Efficacy of unmodified and chemically modified Swietenia mahagoni shells for the removal of hexavalent chromium from simulated wastewater

Rangabhashiyam, S.; Selvaraju, N.

doi:10.1016/j.molliq.2015.06.033

Cited by 89 publications

(22 citation statements)

References 58 publications

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“…The positive values in the change of enthalpy (△H°) indicating that the adsorption process is endothermic, as the diffusion is an endothermic process, the temperature of the solution could have increased the adsorption of ions from of the aqueous solution [37]; this is evidenced in the adsorption results presented in Tables 6 and 8. In addition, the value of the enthalpy change (△H°) is 195362 J/mol, which is in the range between 20000 and 400000 J/mol, thus, it is suggested that the process is dominated by a chemical adsorption mechanism, where the functional groups on the surface of the adsorbent behave as active sites that can interact through chemical bonds [38,39]. On the other hand, the positive value in the change of entropy (△S°) warns the possible reversibility of the process, indicating an increase in the randomness in the liquid-solid interface during the adsorption process, which suggested that the ions of Cr (VI) could replace some water molecules previously adsorbed on the surface of the adsorbent [40,41].…”

Section: Thermodynamic Parametersmentioning

confidence: 99%

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Tovar

Ortega-Toro

2020

redin

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The present work aimed to evaluate the effect of temperature, particle size and bed height of the chromium (VI) adsorption process using plantain peels in a continuous system. The experiment was carried out on a packed bed column, adjusting the feed temperature of the solution with a REX-C100 controller coupled to a type K thermocouple. The initial concentration of Cr (VI) was set at 100 ppm, the pH at 2 and the feed rate of 0.75 mL/s. The analyses were performed by UV-Vis spectroscopy using the colourimetric method of 1.5-diphenylcarbazide. The material was characterized by infrared spectrometry by Fourier Transforms (FTIR), from this analysis, it was determined that the OH and NH2 functional groups are the main responsible for the formation of complexes with the cations in solution. Also, it was established that only the particle size is statistically significant. According to the response surface analysis, the optimum conditions of the process were 353.15 K, a particle size of 0.819 mm and a bed height of 67.768 mm. From the thermodynamic study of the process, it is established that it is endothermic and the chemical adsorption prevails in it. The results obtained in the process modelling suggest that Dose-Response can be used reliably to scale the process.

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Section: Thermodynamic Parametersmentioning

confidence: 99%

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Tovar

Ortega-Toro

2020

redin

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“…[54][55][56][57] Research into adsorption isotherms is crucially important in the modeling, design, and commercial application of adsorbents. [58][59][60] The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherms were expressed as the following eqn (10)- (15).…”

Section: Adsorption Isothermsmentioning

confidence: 99%

Facile synthesis of tea waste/Fe₃O₄nanoparticle composite for hexavalent chromium removal from aqueous solution

et al. 2017

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“…The adsorption peak at 3417 cm -1 indicates the hydroxyl groups and the contribution from C-H stretching, respectively (Nakkeeran et al, 2016a). The band at 2354 cm −1 is assigned to stretching vibrations of N-H or C=O groups probably due to amines and ketones, 1642 cm −1 is an indication of COO, C=O, and can also indicate the bending vibration of adsorbed water (Rangabhashiyam., 2015a), 1030 cm −1 is stretching vibration of C-O-C and O-H of polysaccharides in sawdust (Gode et al, 2008). The absorption peak at 1416 cm −1 could be assigned to CO2 stretching vibration (carbon dioxide from the atmosphere, perhaps due to the mesoporous nature of Ag2O nanomaterials).…”

Section: Fourier Transform Infrared Spectroscopy (Ft-ir) Spectroscopymentioning

confidence: 99%

Preparation and application of silver oxide/sawdust nanocomposite for Chromium(VI) ion removal from aqueous solutions using column system

2017

Global NEST Journal

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This study describes the removal of Cr (VI) ions from aqueous solutions using silver oxide/sawdust nanocomposite (Ag2O/SD NC) that was prepared using the chemical precipitation method. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques were used for characterization of Ag2O/SD NC. The effect of various parameters such as feed solution pH (2, 6, and 10), influent concentration of Chromium (VI) (25-100 mg/L), flow rate (1-5 mL/min) and bed depth (4-12 cm) on breakthrough curves (BTC) were investigated. Three wellknown column adsorption kinetics models including Thomas, Adams-Bohart and Bed Depth Service Time (BDST) models were applied to fitting the column experimental data. Based on Thomas model, the equilibrium adsorption reached 13.41 mg/g when a Cr (VI) polluted solution with influent concentration of 25 mg/L Cr (VI) passed through the column with a flow rate of 2 mL/min. Desorption studies reveal that recovery of uploaded Cr (VI) from the Ag2O/SD NC adsorbent or exhausted column regeneration can readily be achieved using a dilute solution of NaOH (0.01 M) as eluent. This study indicated that the Ag2O/SD NC can be used as an effective, efficient and environmentally friendly adsorbent for the removal of Cr (VI) ions from water resources.

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Efficacy of unmodified and chemically modified Swietenia mahagoni shells for the removal of hexavalent chromium from simulated wastewater

Cited by 89 publications

References 58 publications

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Facile synthesis of tea waste/Fe₃O₄nanoparticle composite for hexavalent chromium removal from aqueous solution

Preparation and application of silver oxide/sawdust nanocomposite for Chromium(VI) ion removal from aqueous solutions using column system

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Efficacy of unmodified and chemically modified Swietenia mahagoni shells for the removal of hexavalent chromium from simulated wastewater

Cited by 89 publications

References 58 publications

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Cr(VI) biosorption: Effect of temperature, particle size and bed height

Facile synthesis of tea waste/Fe3O4nanoparticle composite for hexavalent chromium removal from aqueous solution

Preparation and application of silver oxide/sawdust nanocomposite for Chromium(VI) ion removal from aqueous solutions using column system

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Facile synthesis of tea waste/Fe₃O₄nanoparticle composite for hexavalent chromium removal from aqueous solution