Adsorption of Zinc and Cyanide from Cyanide Effluents on Anionic Ion-exchange Resin

The adsorption of zinc and cyanide from cyanide effluents onto strong and weak basic anion exchange resins was studied in a batch adsorption system. Factors influencing the adsorption rates such as resin selection, resin amounts, contact time and temperature were studied and scanning electron microscopy-energy disperse spectroscopy(SEM-EDS) was used in the analysis. The present study shows that the adsorption capacity of resin 201x7 is better than that of resin 301. The adsorption process was relatively fast and came to equilibrium after 60 min. The kinetic data were analyzed with three models and the pseudo-second-order kinetic model was found to agree with the experimental data well. The equilibrium data could also be described well by Langmuir isotherm model. Thermodynamic parameters such as enthalpy change(Delta H-0) free energy change(Delta G(0)) and entropy change(Delta S-0) were calculated and the adsorption process was spontaneous and endothermic.