Evaluation of Equilibrium Sorption Isotherm Equations

The sorption isotherm is important information for evaluating the ability of an adsorption system to treat the industrial waste water. In this study, eleven datasets from literatures were selected and three two-parameter and threeparameter equations were used to evaluate adsorption systems. Quantitative criteria included six error functions, and the quantitative criterion was residual plots. Isotherm constants differed by linearization and nonlinear regression analysis, especially for the three-parameter equations. The results indicated the inconsistent results of the error functions for selecting the adequate equations. Residual plots were useful to observe the fitting ability of isotherm equations. Temperature has a significant effect on isotherm constants.