Hybrid anion exchange (HAIX) adsorbents showed promising results to remove phosphate to very low concentrations and prevent eutrophication. This work improved the understanding on the adsorption-desorption mechanisms. Firstly, we highlighted how the water conditions, such as the complexity of the matrix and initial phosphate concentration affect the results. Secondly, we revealed a complex mechanism happening during the adsorbent regeneration and phosphate recovery. Finally, thanks to Mössbauer spectroscopy, we managed to provide a fine characterization of the iron oxide nanoparticles and their transformation throughout use. This work provides further knowledge on the functioning and limitations of HAIX applied to phosphate recovery and eutrophication prevention.

Read more:
Belloni, C., L. Korving, G. J. Witkamp, E. Brück, P. de Jager, and A. I. Dugulan. 2023. “FeOOH and (Fe,Zn)OOH Hybrid Anion Exchange Adsorbents for Phosphate Recovery: A Determination of Fe-Phases and Adsorption–Desorption Mechanisms.” Chemical Engineering Journal (Lausanne, Switzerland: 1996) 473 (145287): 145287.