Iron exchange on natural zeolites. Comparison of linear and non-linear regresion analysis methods

Natural zeolites cropped out from Pâglisa (Romania) (P), were evaluated in the process of iron removal from model solutions. Experimental data were evaluated using linear and non-linear regression analysis. A comparison analysis between the two regression methods for estimating the isotherm parameters was made. Experimental data were fitted to Langmuir, Freundlich, and Redlich-Peterson isotherm equations. All four isotherm equations showed a good fit to the experimental data. The results showed that non-linear method could be a better way to obtain the isotherm parameters. Also the Freundlich isotherm proved to describe better iron exchange on natural zeolite.