ANALYSIS OF CALCULATED AND EXPERIMENTAL DATA ON THE SORPTION CAPACITY OF ION EXCHANGE MEMBRANES MA-41 AND MK-40 IN AQUEOUS SOLUTIONS OF FERRIC CHLORIDE (III) AND NICKEL (II) NITRATE

In the processes of ion exchange, a number of regenerating solutions are formed, which must be purified and concentrated for their subsequent use for industrial purposes. For their purification, the possibilities of an electrodialysis process are being considered, where ion exchange membranes with sorption capacity to ferric chloride and sodium nitrate contained in aqueous solutions are used. The aim of the work was to conduct experimental studies on the sorption capacity of MA-41 and MK-40 ion exchange membranes in aqueous solutions of ferric (III) chloride and nickel (II) nitrate, simulating real process solutions, theoretical calculation based on the Freundlich equation and prediction of the corresponding values using an artificial neural network. The paper describes the methodology and results of an experiment to evaluate the sorption capacity of heterogeneous ion-exchange membranes MA-41 and MK-40 in aqueous solutions of iron (III) chloride and nickel (II) nitrate of various concentrations. The experimental results obtained on the sorption capacity clearly demonstrated the different sorption capacity of the MA-41 and MK-40 ion exchange membranes, depending on the solution under study. In FeCl3 solution, the MK-40 membrane showed higher efficiency in ion sorption compared to MA-41. However, the reverse pattern was observed in the Ni(NO3)2×6H2O solution: the sorption capacity of the MA-41 membrane with respect to NO3- anions was higher than that of the MK-40 membrane with respect to Ni2+ cations. The calculated values of the distribution coefficient were obtained using an equation based on the Freundlich equation, and numerical values of empirical coefficients for each type of membrane and ion were determined. Deviations of theoretically calculated values in most cases do not exceed 10%, which indicates a high predictability of membrane behavior in the media under consideration and confirms the correctness of the chosen equation for describing sorption processes.