The thermodynamics of metal ions from stainless steel pickling wastewater on strong-acid cation exchange resin

The adsorption behavior of Cr³⁺ and Fe³⁺ on 001×7 strong-acid cation exchange resin was studied with the static method, respectively getting Adsorption Isotherms of Resin 001×7 for Cr³⁺ and Fe³⁺. The experimental results show that, in the studied concentration range, the equilibrium adsorption data of Cr³⁺ fit to Langmiur isotherms, while Fe³⁺ fitting to Frendlich isotherms. Kinetic analysis show that the adsorption rate of Cr³⁺ is mainly governed by liquid film diffusion and the rate of Fe³⁺ is governed by Particle diffusion. In addition, the thermodynamic parameters were obtained from analyzed dynamics data and thermodynamic function. The conclusion indicates that the adsorption gets more orderly and is an exothermic process running spontaneously, so that higher temperature is bad for the reaction.