Regression analysis for the sorption isotherms of basic dyes on sugarcane dust

The sorption of three basic dyes, named basic violet 10, basic violet 1, and basic green 4, from aqueous solutions onto sugarcane dust was studied. The results revealed the potential of sugarcane dust, a waste material, to be a low-cost sorbent. Equilibrium isotherms were analyzed using the Langmuir, the Freundlich, and the three-parameter Redlich-Peterson isotherms. In order to determine the best-fit isotherm for each system, two error analysis methods were used to evaluate the data: the linear coefficient of determination and the Chi-square statistic test for determination of a non-linear model. Results indicated that the Chi-square test provided a better determination for the three sets of experimental data.