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

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

Belloni, C. (TU Delft RST/Fundamental Aspects of Materials and Energy; Wetsus, Centre for Sustainable Water Technology)
Korving, L. (Wetsus, Centre for Sustainable Water Technology)
Witkamp, G.J. (TU Delft BT/Environmental Biotechnology; King Abdullah University of Science and Technology)
Brück, E.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Dugulan, A.I. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RID/TS/Instrumenten groep)

2024

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 (α-FeOOH), a highly stable phase, have been synthesized with increasing Zn²⁺-doping, 0–20 %at. Zn/Fe, to manipulate the surface properties, following the results of a previous work. Mössbauer spectroscopy showed preserved goethite phase and increased point of zero charge (pzc) at low Zn-doping percentages, while at higher percentages (>5%at.) co-existing phases with increased specific surface area formed. Low concentrations (0.1–10 mg L⁻¹) batch adsorption tests showed increased P removal per unit mass with increasing doping. However, the highest pzc, affinity and P removal per unit area were observed for the 5%at. doped sample, suggesting this dopant concentration to provide the most effective surface. A regeneration test, performed at a lower pH than usual, showed preserved, even improved P desorption with increasing doping. Mössbauer spectroscopy showed that the nanoparticle phase and composition, up to 5%at., doping was preserved throughout the process. These results are promising to develop a stable effective Zn-doped goethite-based adsorbent for P recovery at ultra-low concentrations.

Adsorption
Goethite
Iron oxide
Phosphate recovery
Regeneration
Zinc doping

http://resolver.tudelft.nl/uuid:4a0305a6-4b2f-41d9-981e-7aedf6c30b5d

https://doi.org/10.1016/j.colsurfa.2024.133476

0927-7757

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 687

Institutional Repository

journal article

© 2024 C. Belloni, L. Korving, G.J. Witkamp, E.H. Brück, A.I. Dugulan