Microplastics Influence Phosphate Adsorption in Volcanic Ash Soil
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Date
Authors
PESENTI PEREZ, HECTOR GONZALO
Suazo-Hernández, Jonathan
Cáceres-Jensen, Lizethly
Pesenti, Héctor
Corradini, Fabio
de la Luz Mora, María
Bolan, Nanthi Sirangie
Cornejo, Pablo E.
Sarkar, Binoy
Suazo-Hernández, Jonathan
Cáceres-Jensen, Lizethly
Pesenti, Héctor
Corradini, Fabio
de la Luz Mora, María
Bolan, Nanthi Sirangie
Cornejo, Pablo E.
Sarkar, Binoy
Authors
Date
Datos de publicación:
10.1007/s42729-025-02472-2
Keywords
Emerging Contaminants - Eutrophication - Plant Nutrients - Plastic Pollution - Soil Phosphorus
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Abstract
Purpose: There is a debate whether microplastic particles released into soils can modify phosphorus bioavailability by altering the soil surface properties. Here, we aim to explore the impact of polyethylene microplastics (PE MPs) on the adsorption–desorption of inorganic phosphate anions (P) on a volcanic ash soil (VAS).
Methods: Batch P adsorption–desorption experiments were conducted in a Chilean VAS with and without 1% (w/w) PE-MPs addition, taking P concentrations (KH₂PO₄ dissolved in 0.01 mol L⁻¹ NaCl background solution) ranging from 0.02 to 6.47 mmol L⁻¹, with a solid (g):liquid (mL) ratio of 1:40, and at a pH range of 4.5 to 10.5 at 20 ± 1 °C. The VAS and VAS/PE-MPs systems were characterized, and kinetic and isotherm adsorption data were modeled to predict mechanisms.
Results: The Elovich model described the kinetic P adsorption data on VAS with and without 1% PE-MPs (r² ≈ 0.985 and χ² ≈ 12). Adsorption isotherms fitted well to the Freundlich model (r² ≈ 0.994 and χ² ≈ 6.39), indicating a highly heterogeneous surface for both systems. The Freundlich model indicated an increase in P adsorption capacity from 49.55 (mmol kg⁻¹)(L mmol⁻¹)¹/ⁿ for VAS to 54.66 (mmol kg⁻¹)(L mmol⁻¹)¹/ⁿ for VAS + 1% PE-MPs. Desorption of P was higher in the VAS + 1% PE-MPs system compared to VAS alone. For both systems, solution pH showed no significant changes in P adsorption on VAS.
Scanning electron microscopy–energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy results showed that P was bound to PE-MPs through weak van der Waals forces and/or a pore-filling mechanism.
Conclusion: This study demonstrated that PE-MPs in VAS could modify surfaces available for P adsorption and act as a carrier to enhance P mobility.
© 2025 Elsevier B.V. All rights reserved.
Description
Keywords
Emerging Contaminants , Eutrophication , Plant Nutrients , Plastic Pollution , Soil Phosphorus
Citation
10.1007/s42729-025-02472-2