Sorption equilibria of chlorinated anilines in aqueous solution on resin-bound cobalt ion

Studies have been made of the sorption equilibria of chlorinated anilines in aqueous solution on ligand exchange resin. The chlorinated anilines used included 2-chloroaniline, 3-chloroaniline, 4-chloroaniline and 2,5-dichloroaniline. A mini-column apparatus was used to study sorption of chlorinated anilines onto ligand exchange resin. The experiments were conducted in a constant temperature at 25±0.1 °C. The sorption behaviour of these chlorinated anilines on Co(II)-loaded carboxylated diaminoethyl sporopollenin (CDAE-sporopollenin) can be expressed by the Langmuir and Freundlich isotherms. The characteristics of the sorption process were also investigated using Scatchard plot analysis (q/C vs. q). When the Scatchard plot showed a deviation from linearity, greater emphasis was placed on the analysis of the adsorption data in terms of the Freundlich model, in order to construct the adsorption isotherms of the ligand(s) at particular concentration(s) in solutions. Equilibrium binding data for ligands gave rise to a linear plot, indicating that the Langmuir model could be applied. Ligand adsorption constants, dissociation constant (Kd) and correlation coefficients for the ligands were calculated from Langmuir and Freundlich isotherms.