Efficiency of electrochemical membrane cleaning of process solutions from copper sulphate and trisodium phosphate

Abstract

The paper considers the potential practical application of an electrochemical membrane method in the process of copper sulfate and trisodium phosphate removal from industrial water. The research objects were process solutions containing copper sulfate and trisodium phosphate and semipermeable polymeric membranes with various selective permeability characteristics. The study covers the effect that the transmembrane parameters of electromembrane separation have on the main kinetic characteristics of MGA-95P and OPM-K membranes in the process of copper smelting production water treatment. Approximation expressions were obtained to calculate membrane rejection rate depending on the physicochemical basis of the semipermeable membrane polymer, transmembrane pressure as well as process solution concentration and temperature. Empirical coefficients were determined to calculate and predict rejection rate values that can be used in the design of laboratory, pilot and industrial units used in the separation, treatment and concentration of industrial and waste water. The mathematical model of mass transfer was developed for electrochemical membrane separation taking into account assumptions made based on the solutions of the Nernst—Planck and Poisson—Boltzmann equations. This model allows for process physical description and calculations of concentration fields in the intermembrane channel and concentration changes in permeate and retentate lines. The mathematical model was checked for adequacy by comparing experimental data on retention rate with theoretical values where discrepancies between the experimental and theoretical data were within the limits of the experimental error and the error of calculated values.