Evaluation by Means of Electrochemical Impedance Spectroscopy of the Transport of Phosphate Ions through a Heterogeneous Anion-Exchange Membrane at Different pH and Electrolyte Concentration

Electrodialysis is an innovative technique to reclaim phosphates from municipal wastewater. However, chemical reactions accompany the transport of these ions through ion-exchange membranes. The present study investigates dependence phenomena on initial pH and concentration phosphate-containing solution using a heterogeneous anion-exchange membrane. Linear sweep voltammetry, electrochemical impedance spectroscopy, chronopotentiometry experiments were conducted for different systems. For most diluted solution, two limiting current densities (ilim) have been observed 5 7.2, while only one ilim 10, correlated with appearance Gerischer arcs in EIS spectra. sub-arcs separated by loop, indicating involvement membrane functional groups. Increasing phosphate changed system’s characteristics, reporting single ilim. In spectra, absence elements determined attenuation reactions, followed development diffusion boundary layer, as indicated finite-length Warburg arcs. Chronopotentiometry clarified mass mechanism responsible distorting layer thickness at lower concentrations. obtained results are expected contribute recovery electrodialysis varied conditions available environment.