Equilibrium and kinetic studies for removal of malachite green from aqueous solution by a low cost activated carbon

2013 ◽  
Vol 19 (4) ◽  
pp. 1099-1105 ◽  
Author(s):  
Uma ◽  
Sushmita Banerjee ◽  
Yogesh C. Sharma
2021 ◽  
Vol 12 (1) ◽  
pp. 1247-1262

This research work involved using factorial experimental design techniques to investigate the adsorption of hexavalent chromium from an aqueous solution on medlar activated carbon. A 24 full factorial experimental design was employed to determine the optimum values and degree of importance of parameters: pH, initial Cr (VI) concentration, adsorbent dose, and contact time at two levels. The optimized conditions for hexavalent chromium Cr (VI) removal were at initial pH 1.5, 5 mg.L−1Cr (VI), adsorbent dose 6 mg, and 60 min adsorption time. The results predicted a good agreement between the predicted values (R2= 0.9909), as obtained by the model, and the experimental value (R2= 0.9977). The main effects and interaction effects were analyzed using analysis of variance (ANOVA), F-test and P-values to define the most important process variables affecting Cr (VI) adsorption. The most significant variables were therefore the pH of the solution and the adsorbent dose. Therefore, the present results demonstrate that medlar activated carbon should be regarded as a low-cost alternative for removing Cr (VI) from an aqueous solution. The adsorption data were evaluated by Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The results showed that the Langmuir isotherm model best describes the equilibrium adsorption with a high correlation coefficient.


2014 ◽  
Vol 9 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Rajeshwar M. Shrestha ◽  
Margit Varga ◽  
Imre Varga ◽  
Amar P. Yadav ◽  
Bhadra P. Pokharel ◽  
...  

Activated carbons were prepared from Lapsi seed stone by the treatment with H2SO4 and HNO3 for the removal of Ni (II) ions from aqueous solution. Two activated carbon have been prepared from Lapsi seed stones by treating with conc.H2SO4 and a mixture of H2SO4 and HNO3 in the ratio of 1:1 by weight for removal of Ni(II) ions. Chemical characterization of the resultant activated carbons was studied by Fourier Transform Infrared Spectroscopy and Boehm titration which revealed the presence of oxygen containing surface functional groups like carboxyl, lactones and phenols in the carbons. The optimum pH for nickel adsorption is found to be 5. The adsorption data were better fitted with the Langmuir equations than Freundlich adsorption equation to describe the equilibrium isotherms. The maximum adsorption capacity of Ni (II) on the resultant activated carbons was 28.25.8 mg g-1 with H2SO4 and 69.49 mg g-1 with a mixture of H2SO4 and HNO3. The waste material used in the preparation of the activated carbons is inexpensive and readily available. Hence the carbons prepared from Lapsi seed stones can act as potential low cost adsorbents for the removal of Ni (II) from water. DOI: http://dx.doi.org/10.3126/jie.v9i1.10680Journal of the Institute of Engineering, Vol. 9, No. 1, pp. 166–174


2021 ◽  
Vol 12 (2) ◽  
pp. 2022-2040

Almond shell (AS) is a low-cost adsorbent used in this study for the removal of methylene blue (MB), crystal violet (CV), and Congo red (CR) from an aqueous solution in single and mixture binary systems. The low-cost adsorbent was characterized by FTIR and SEM analysis. The effects of AS dose, contact time, initial dye concentration, pH, and temperature on MB, CV, and CR adsorption were studied in a single system. In a binary system, the MB, CV, and CR were removed from the mixture of MB+CR, CV+MB, and CV+CR with a percentage in volume ranging from 0 to 100 % in MB and CV, and CR. Kinetic studies showed rapid sorption following a second-order kinetic model with of contact time of 10 min. The modulation of adsorption isotherms showed that retention follows the Langmuir model. The thermodynamic parameters proved that the MB, CV, and CR adsorption process was feasible, spontaneous, and exothermic. The synergy adsorption between dyes in a binary mixture of MB+CR and CV+CR, while the competition adsorption between dyes in a binary mixture of MB+ CV.


2020 ◽  
Vol 9 (1) ◽  
pp. 318-327

Adsorption is a widely used technique for wastewater remediation. The process is effective and economical for the removal of various pollutants from wastewater, including dyes. Moreover, Besides commercial activated carbon, different low-cost materials such as agricultural and industrial wastes are now used as adsorbents. The present review focused on the removal of a teratogenic and carcinogenic dye, orange G (OG) via adsorption using several adsorbents, together with the experimental conditions and their adsorption capacities. Based on the information compiled, various adsorbents have shown promising potential for OG removal.


2014 ◽  
Vol 875-877 ◽  
pp. 196-201 ◽  
Author(s):  
Mohd Faisal Taha ◽  
Ahmad S. Rosman ◽  
Maizatul S. Shaharun

The potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Pb (II) ion from aqueous solution was investigated. Rice husk-based activated carbon was preparedviachemical activation process using NaOH followed by the carbonization process at 500°C. Morphological analysis was conducted using field-emission scanning electron microscope /energy dispersive X-ray (FESEM/EDX) on three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon. These three samples were also analyzed for their C, H, N, O and Si contents using CHN elemental analyzer and FESEM/EDX. The textural properties of rice husk-based activated carbon, i.e. surface area (253 m2/g) and pore volume (0.17 cm2/g), were determined by N2adsorption. The adsorption studies using rice husk-based activated carbon as an adsorbent to remove Pb (II) ion from aqueous solution were carried out at a fixed initial concentration of Pb (II) ion (150 ppm) with varying adsorbent dose as a function of contact time at room temperature. The concentration of Pb (II) ion was determined by atomic absorption spectrophotometer (AAS). The removal of Pb (II) ion from aqueous solution increased from 35 % to 82 % when the amount of rice husk-based activated carbon was increased from 0.05 g to 0.30 g. The equilibrium data obtained from adsorption studies was found to fit both Langmuir and Freundlich adsorption isotherms.


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