Zn induced surface modification of stable goethite nanoparticles for improved regenerative phosphate adsorption

Iron oxide-based adsorbents showed potential to reach ultra-low phosphorus (P) concentrations to prevent eutrophication and recover P. High affinity, high capacity at low P concentrations (<1 mg L⁻¹), good stability, and reusability of the adsorbent are key factors for economic viability. In this study, nanoparticles of goethite...

Effect of goethite doping using elements with different preferential oxidation states for improved reversible phosphate adsorption

Phosphorus (P) removal from freshwater bodies to ultra-low concentrations is fundamental to prevent eutrophication, while its recovery is necessary to close the P usage cycle. Iron oxide-based adsorbents seem promising candidates, being abundant, cheap, and easy to synthesize compounds, with good affinity for P. Affinity is the key parameter...

FeOOH and (Fe,Zn)OOH hybrid anion exchange adsorbents for phosphate recovery: A determination of Fe-phases and adsorption–desorption mechanisms

Hybrid anion exchange adsorbents (HAIX) seem promising to prevent eutrophication and recover phosphate (P). HAIX consist of an anion exchange resin (AIX) backbone, promoting anion physisorption (outer-sphere complex), impregnated with iron (hydr)oxide nanoparticles (NPs), for selective P chemisorption (inner-sphere complex). In this work, for...

Efficient formation of vivianite without anaerobic digester: Study in excess activated sludge

It was recently discovered that vivianite (Fe₃(PO₄)₂.8H₂O) could be magnetically extracted from digested activated sludge which opened a new route for phosphorus recovery (Wijdeveld et al. 2022). While its formation in digested sludge is regularly reported, it is not yet studied for fresh,...

Improving iron oxide-based adsorbents for phosphate recovery from surface water using Mössbauer spectroscopy as main analytical tool

This thesis focuses on recycling resources while preserving water quality and availability. This concept is at the basis of a healthy and sustainable society yet works needs to be done. Water scarcity will be a growing challenge that humanity will have to face in the coming years, due to poor resource management and the climate change crisis....