Adsorption kinetics of chromium(III) removal from aqueous solutions using natural red earth

Nikagolla, Chandima; Chandrajith, Rohana; Weerasooriya, Rohan; Dissanayake, C.B.

doi:10.1007/s12665-012-1767-z

Cited by 17 publications

(3 citation statements)

References 14 publications

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“…The adsorption capacity of Cr(VI) increases from 4.2 to 5.1 mg g –1 when the pH is raised from 1 to 3 and then drops gradually to 4.8 mg g –1 with the pH raised to 7, whereas the adsorption capacity drops sharply to 0.3 mg g –1 after the pH changes from 7 to 10. The reason is that the distribution of Cr(VI) species and the functional groups on the adsorbent surface are greatly affected by the pH …”

Section: Resultsmentioning

confidence: 99%

“…The reason is that the distribution of Cr(VI) species and the functional groups on the adsorbent surface are greatly affected by the pH. 46 Generally, the hexavalent chromium exists in six forms in aqueous solutions, including HCr 2 O 7 − , Cr 3 O 10 2− , H 2 CrO 4 , HCrO 4 − , Cr 2 O 7 2− , CrO 4 2− , which depend on the pH of the aqueous solution and the concentration of hexavalent chromium. 47,48 HCr 2 O 7 − and Cr 3 O 10 2− can be detected at pH < 0 or the concentration of Cr(VI) higher than 1 M, 49 whereas H 2 CrO 4 is predominant at pH < 1.0.…”

Section: Resultsmentioning

confidence: 99%

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Adsorption of Hexavalent Chromium from Aqueous Solution by a Chitosan/Bentonite Composite: Isotherm, Kinetics, and Thermodynamics Studies

2020

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In this work, the chitosan/bentonite composite was favorably prepared and further used for Cr(VI) removal from aqueous solutions via a batch adsorption process. The characteristics of the chitosan/bentonite composite were determined by using scanning electron microscopy, Brunner–Emmet–Teller measurement, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction, and the results reveal the evidence of the interaction between functional groups of chitosan with bentonite, which is helpful for the adsorption of Cr(VI). The adsorption performance of the chitosan/bentonite composite is better than that of chitosan or bentonite, and the effects of adsorbent dosage, shaking speed, pH, and temperature were investigated. The results indicate that the percentage removal of Cr(VI) increases with an increase in adsorbent dosage, the external diffusion resistance is maintained constant when the shaking speed exceeds 210 rpm, and the optimum pH is 3. The isotherm and kinetic experimental data of Cr(VI) adsorption onto the chitosan/bentonite composite were best-fitted by Redlich–Peterson and Elovich models, respectively. The adsorption process is an exothermic and of the multilayer variety. The desorption rates of Cr(VI) can be achieved at 60.1% with 0.1 M NaOH. The analysis FT-IR of adsorbents before and after adsorption, adsorption thermodynamics and kinetics, and desorption experiment reveal that the adsorption of Cr(VI) on the chitosan/bentonite composite is predominantly a chemical interaction. The above results suggested that the chitosan/bentonite composite can be employed as a cost-effective and environmentally friendly adsorbent for Cr(VI) removal from wastewater.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Adsorption of Hexavalent Chromium from Aqueous Solution by a Chitosan/Bentonite Composite: Isotherm, Kinetics, and Thermodynamics Studies

2020

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“…Adsorption is a process by which chromium(III) can be removed from tanning wastewater. Even though such depollution has only been carried out at laboratory scale so far, acceptable results were obtained with various adsorbents [10][11][12][13][14][15][16][17][18]. The most effective solids for this purpose are characterized by the fact that they develop strong electrostatic interactions.…”

Section: Introductionmentioning

confidence: 99%

Chromium(III) recovery from tanning wastewater by adsorption on activated carbon and elution with sulfuric acid

Hintermeyer

Tavani

2016

Environmental Engineering Research

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Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and 40°C, establishing what temperature favored chromium(III) uptake. At 40°C, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at 70°C (13.23 g/L Cr 3+ ; 42.98 g/L sulfate; and 0.40 g/L NaCl).

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Hydrogeochemical factors controlling the occurrence of chronic kidney disease of unknown etiology (CKDu)

Shi

Gao

Guo

et al. 2022

Environ Geochem Health

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Adsorption kinetics of chromium(III) removal from aqueous solutions using natural red earth

Cited by 17 publications

References 14 publications

Adsorption of Hexavalent Chromium from Aqueous Solution by a Chitosan/Bentonite Composite: Isotherm, Kinetics, and Thermodynamics Studies

Adsorption of Hexavalent Chromium from Aqueous Solution by a Chitosan/Bentonite Composite: Isotherm, Kinetics, and Thermodynamics Studies

Chromium(III) recovery from tanning wastewater by adsorption on activated carbon and elution with sulfuric acid

Hydrogeochemical factors controlling the occurrence of chronic kidney disease of unknown etiology (CKDu)

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