Abstract

Colloids and nanoparticles leached from agricultural land are major carriers of potentially bioavailable nutrients with high mobility in the environment. Despite significant research efforts, accurate knowledge of macronutrients in colloids and nanoparticles is limited. We used multi-elemental synchrotron X-ray fluorescence (XRF) microscopy with multivariate spatial analysis and X-ray atomic absorption near-edge structure (XANES) spectroscopy at the P and S K-edges, to study the speciation of P and S in two fractions of leached particles, >0.45 and <0.45 mu m respectively, collected from four tile-drained agricultural sites in Sweden. P K-edge XANES showed that organic P, followed by P adsorbed to surfaces of aluminum-bearing particles were the most common forms of leached P. Iron-bound P (Fe-P) forms were generally less abundant (0-30 % of the total P). S K-edge XANES showed that S was predominantly organic, and a relatively high abundance of reduced S species suggests that redox conditions were adverse to the persistence of P bound to Fe-bearing colloids in the leachates. Acid ammonium-oxalate extractions suggested that P associated with Al and Fe (Al-P and Fe-P) in most cases could be explained by the adsorption capacity of non-crystalline (oxalate-extractable) oxides of Al and Fe. These results improve our understanding of particulate P and S speciation in the vadose zone and helps in developing effective technologies for mitigating colloidal driven eutrophication of water bodies near agricultural land. (C) 2020 The Author(s). Published by Elsevier Ltd.

Keywords

Leachates; Colloids; Nanoparticles; Phosphorus; Sulfur; Speciation

Published in

Water Research
2021, Volume: 189, article number: 116585
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Adediran, Gbotemi

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Lundberg, Daniel

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Almkvist, Gunnar

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Hillier, Stephen

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • The James Hutton Institute

• Gustafsson, Jon-Petter

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Simonsson, Magnus

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science
Soil Science


Publication identifier

DOI: https://doi.org/10.1016/j.watres.2020.116585

Permanent link to this page (URI)

https://res.slu.se/id/publ/110421