Three isotherm models, Langmuir, Freundlich and Sips model (Equations 2-4), were used to help understand our adsorption system. The Langmuir model, which speaks to monolayer adsorption on a homogeneous surface, and the Freundlich model, which speaks to multilayer adsorption on a heterogeneous surface, are the simplest and most extensively applied isotherm models in adsorption systems. The Sips model on the other hand is a combination of both the Langmuir and Freundlich which can be used to describe either a homogeneous or heterogeneous system. The Sips model reduces to the Freundlich isotherm when concentration is low and to the Langmuir isotherm when n s approaches 1.