Sorption isotherm for safranin onto rice husk: Comparison of linear and non-linear methods

Comparison analysis of linear least-square method and non-linear method for estimating the isotherm parameters was made. Comparison analysis was made using the experimental equilibrium data of safranin onto rice husk at a solution temperature of 305 K. Sorption data were fitted to Freundlich, Langmuir and Redlich–Peterson isotherm equations. All the three isotherm equations showed a better fit to the experimental data. The results show that non-linear method could be a better way to obtain the isotherm parameters. Redlich–Peterson isotherm is a special case of Langmuir isotherm when the Redlich–Peterson isotherm constant g was unity.