These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The removal of the indigo carmine dye from aqueous solutions using cross-linked chitosan: evaluation of adsorption thermodynamics using a full factorial design.
    Author: Cestari AR, Vieira EF, Tavares AM, Bruns RE.
    Journal: J Hazard Mater; 2008 May 01; 153(1-2):566-74. PubMed ID: 17913348.
    Abstract:
    A 2(3) factorial design was employed to evaluate the quantitative removal of the indigo carmine (IC) dye from aqueous solutions on glutaraldehyde cross-linked chitosan. The variables were chitosan masses of 100 and 300 mg, IC concentrations of 2.0 and 5.0 x 10(-5) mol L(-1) and temperatures of 25 and 35 degrees C. The quantitative and energetic adsorption parameters were analyzed statistically using modeling with bilinear equations. The results indicated that increasing the chitosan mass from 100 to 300 mg decreases the IC adsorption/mass ratio (mol g(-1)) whereas a temperature increase of 25-35 degrees C increases it. The principal effect of the IC concentration did not show statistical significance. The factorial experiments demonstrate the existence of a significant antagonistic interaction effect between the chitosan mass and temperature. The adsorption thermodynamic parameters, namely Delta(ads)H, Delta(ads)G, and Delta(ads)S, were determined for all the factorial design results. Endothermic values were found in relation to the Delta(ads)H. The positive Delta(ads)S values indicate that entropy is a driving force for adsorption. The Delta(ads)G values are also significantly affected by important antagonistic and synergistic effects involving all principal and interactive factors. It is concluded that the thermodynamical spontaneity of the IC adsorption parameters are greatly influenced by the interactive factors and not by the temperature changes alone.
    [Abstract] [Full Text] [Related] [New Search]