Application of Two-and Three-Parameter Isotherm Models: Biosorption of Acid Red 88 onto Azolla microphylla

Author: Padmesh T.   Vijayaraghavan K.   Sekaran G.   Velan M.  

Publisher: Taylor & Francis Ltd

ISSN: 1088-9868

Source: Bioremediation Journal, Vol.10, Iss.1-2, 2006-07, pp. : 37-44

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Abstract

Biosorption potential of Azolla microphylla for acid red 88 from aqueous solution was investigated under laboratory conditions as a function of initial pH and temperature. The algal biomass exhibited the highest dye sorption capacity at optimum conditions of pH 3 and temperature 30°C. The experimental isotherms were analyzed using five two-parameter models (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Flory-Huggins) and five three-parameter models (Redlich-Peterson, Sips, Khan, Radke-Prausnitz, and Toth). Three error analysis methods were used to evaluate the experimental data: correlation coefficient, residual root mean square error (RMSE), and chi-square test to find the best fitting isotherm. In particular, Langmuir (two-parameter) and Khan (three-parameter) models described the dye biosorption isotherm data well at all pH and temperature conditions examined.