Modified Correlations for Adsorption Isotherms

In this research, new correlations for adsorption were developed. Classical adsorption isotherm models such as Freundlich, Langmuir, and Redlich–Peterson were modified to account for the effect of temperature by utilizing a superposition shift factor. The new correlations contain two independent variables; concentration (C e) and temperature (T). The modified correlations developed by this research were validated by the results of three independent studies reported by others in the past, and were found to perfectly predict the experimental adsorption data presented by these three studies. Furthermore, by using these modified correlations one may get the amount of adsorbate per adsorbent (Q e) at any concentration and temperature by only knowing the adsorption isotherm data, that is, Q e vs C e, at a single reference temperature. This is not possible with the use of the existing adsorption isotherm models since a change in temperature changes the parameters of the equation as well.