Isotherms and thermodynamics by linear and non-linear regression analysis for the sorption of methylene blue onto activated carbon: Comparison of various error functions

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Vasanth V Kumar (Author) Other; Porkodi, K (Author) Other; Rocha, F (Author) FEUP

Journal

Title: Journal of Hazardous Materials

Vol. 151 No. 2

Pages: 794-804

ISSN: 0304-3894

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 140 Citations

ISI Web of Science

Scopus - 156 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Civil engineering

CORDIS: Technological sciences > Engineering > Chemical engineering

Other information

Authenticus ID: P-004-17V

DOI: 10.1016/j.jhazmat.2007.06.056

Abstract (EN): A comparison of linear and non-linear regression method in selecting the optimum isotherm was made to the experimental equilibrium data of methylene blue sorption by activated carbon. The r(2) was used to select the best fill linear theoretical isotherm. In the case of non-linear regression method, six error functions, namely coefficient of determination (r(2)), hybrid fractional error function (HYBRID), Marquardt's percent standard deviation (MPSD), average relative error (ARE), sum of the errors squared (ERRSQ) and sum of the absolute errors (EABS) were used to predict the parameters involved in the two and three parameter isotherms and also to predict the optimum isotherm. For two parameter isotherm, MPSD was found to be the best error function in minimizing the error distribution between the experimental equilibrium data and predicted isotherms. In the case of three parameter isotherm, r2 was found to be the best error function to minimize the error distribution structure between experimental equilibrium data and theoretical isotherms. The present study showed that the size of the error function alone is not a deciding factor to choose the optimum isotherm. In addition to the size of error function, the theory behind the predicted isotherm should be verified with the help of experimental data while selecting the optimum isotherm. A coefficient of non-determination, K-2 was explained and was found to be very useful in identifying the best error function while selecting the optimum isotherm.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11