Modeling competitive adsorption of Zn and Cd ions by dried activated sludge using a Freundlich-type multi-component isotherm

In this work, the Sheindorf–Rebuhn–Sheintuch (SRS) equation, a Freundlich-type isotherm,in representing the competitive adsorption of Zn and Cd ions by dried activated sludge, wasexamined. The SRS equation is [1]: ??????????????? where qi is the adsorption capacity i component in mol / gr , Ci and Cj are the equilibriumconcentrations of i and j component in the solution in M , Ki and ni are the Freundlichconstants obtained for i in a single-component system, and aij is the competition adsorptioncoefficient of i component in the presence of j component.The bicomponent isotherm can be written as: ????????? According to SRS equation (1), for a bicomponent system, the adsorption capacity by eachcomponent is given by[1]: ???????? The aim of this study to determine the competition coefficients in bicomponent systems andto model the experimental results using the SRS equation.