Various isotherm models for multicomponent adsorption: A review

Adsorption is considered as the efficient method for the removal of pollutant from wastewater. The wastewater contains single pollutant as well as multi-pollutants. In case of wastewater having various pollutants, interaction and competition among the adsorbate molecules plays an important role in the adsorption process. The adsorption mechanism will be complicated for these systems. Therefore for understanding the mechanism, different single component isotherm models are modified to multi-component systems. Various isotherm models such as non-modified Langmuir, extended Langmuir, modified Langmuir model, extended Freundlich, Redlich-Peterson model, Sheindorf–Rebuhn–Sheintuch equation and extended Sips isotherm model were studied in order to understand the interaction among the pollutant molecules. Therefore, the current study reviews the different isotherm models used for multicomponent adsorption