Kinetics of H⁺/Cu²⁺ Ion Exchange on KPS and KS-10 Wofatits

Abstract

Ion exchange allows the recovery of water and heavy metals from exhausted electroplating baths and wastewaters. The rate of ion exchange depends on experimental conditions and is determined by diffusion processes.

Investigations of the kinetics of H⁺/Cu²⁺ ion exchange were carried out on strongly acid cation exchangers: gel Wofatit KPS and macroporous Wofatit KS-10. Dependence of rate of H⁺/Cu²⁺ ion exchange on temperature in the range from 303 to 363 K was determined at initial concentration of Cu(II) from 0.0125 up to 0.05 mole/dm³ and at acidity of solution up to 0.5 mole H⁺/dm³. The data obtained illustrate the effect of increase in H⁺ on H⁺/Cu²⁺ exchange. This has no influence on the half-life time of ion exchange in Wofatit KS-10, and in the case of Wofatit KPS only at H⁺ concentrations lower than 0.25 mole/dm³. However, the concentration of H⁺ ions has a significant influence on the amount of Cu²⁺ ions exchanged.

A simplified kinetic equation, according to equation of a first order chemical reaction, is given. This equation was used to determine rate constants of H⁺/Cu²⁺ ion exchange; the average values proved the diffusion character of the process.