Synergistic effects of biochar and vegetation on microplastic and nanoplastic removal from stormwater runoff in bioretention systems
11 affiliations
- 1School of Environmental Sciences
- 2University of Guelph
- 3Department of Chemical Engineering
- 4McGill University
- 5Département de génie civil et de génie des eaux
- 6Université Laval
- 7Institute of Forestry and Conservation
- 8University of Toronto
- 9Department of Construction Engineering
- 10École de technologie supérieure
- 11United Nations University Institute for Water, Environment and Health
Abstract
Microplastics and nanoplastics (MNPs) are emerging contaminants in stormwater runoff, posing potential ecological and human health risks. Bioretention systems offer promising nature-based stormwater treatment, yet their performance remains highly variable. Biochar, particularly post-processed biochar, has demonstrated strong potential for contaminant removal; however, its effects on MNP removal, leachate quality, and plant performance in green infrastructure remain poorly understood. Here, we investigated the combined effects of untreated and thermal air-oxidated (hereinafter: treated) biochars and native vegetation ( Rudbeckia hirta ) on the removal of polystyrene MNPs (0.02, 0.2, and 1 μm) from synthetic stormwater runoff, leachate quality and plant performance in bioretention systems. Both biochars effectively removed nanoplastics during the early MNP-spiked storm events. Vegetation substantially reduced MNP leaching during subsequent simulated rainfall events, supported by the detection of microplastics within root tissues, indicating plant uptake. Vegetation also reduced nutrient leaching, with larger plants exhibiting more pronounced effects, highlighting the importance of enhancing plant growth for contaminant removal. Although treated biochar reduced total organic carbon leaching during initial spiking events, both biochars increased P, K, and S leaching. Overall, our findings demonstrate synergistic effects of biochar and vegetation in enhancing contaminant retention in bioretention systems, advancing green infrastructure design and sustainable stormwater management.
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BibTeX
@misc{liao2026synergistic,
title = {{Synergistic effects of biochar and vegetation on microplastic and nanoplastic removal from stormwater runoff in bioretention systems}},
author = {Wenxi Liao and Georgina C. Kalogerakis and Ana C. Quevedo and Thalia Azadian and Sean C. Thomas and Mathieu Lapointe and Nathalie Tufenkji},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010823/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010823/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Synergistic effects of biochar and vegetation on microplastic and nanoplastic removal from stormwater runoff in bioretention systems
AU - Wenxi Liao
AU - Georgina C. Kalogerakis
AU - Ana C. Quevedo
AU - Thalia Azadian
AU - Sean C. Thomas
AU - Mathieu Lapointe
AU - Nathalie Tufenkji
PY - 2026
DA - 2026/10/22
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010823/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010823/v1
AB - Microplastics and nanoplastics (MNPs) are emerging contaminants in stormwater runoff, posing potential ecological and human health risks. Bioretention systems offer promising nature-based stormwater treatment, yet their performance remains highly variable. Biochar, particularly post-processed biochar, has demonstrated strong potential for contaminant removal; however, its effects on MNP removal, leachate quality, and plant performance in green infrastructure remain poorly understood. Here, we investigated the combined effects of untreated and thermal air-oxidated (hereinafter: treated) biochars and native vegetation ( Rudbeckia hirta ) on the removal of polystyrene MNPs (0.02, 0.2, and 1 μm) from synthetic stormwater runoff, leachate quality and plant performance in bioretention systems. Both biochars effectively removed nanoplastics during the early MNP-spiked storm events. Vegetation substantially reduced MNP leaching during subsequent simulated rainfall events, supported by the detection of microplastics within root tissues, indicating plant uptake. Vegetation also reduced nutrient leaching, with larger plants exhibiting more pronounced effects, highlighting the importance of enhancing plant growth for contaminant removal. Although treated biochar reduced total organic carbon leaching during initial spiking events, both biochars increased P, K, and S leaching. Overall, our findings demonstrate synergistic effects of biochar and vegetation in enhancing contaminant retention in bioretention systems, advancing green infrastructure design and sustainable stormwater management.
ER -