Abstract
Biochar has recently been identified as a potential solution for the remediation of organic micropollutants from contaminated water. Herein, we have assessed the potential mitigation of per- and polyfluoroalkyl substances (PFAS) by means of biochar adsorption as a green alternative to coal-based sorbents for PFAS-polluted stormwater systems. For this purpose, 13 biochar materials (originating from diverse feedstocks as well as intended for both commercial and research purposes) were initially screened for PFAS remediation capabilities in static flow systems. These experiments pointed to biochar sorption as a promising strategy for PFAS remediation, with some materials showing removal efficiencies of around 99% after 7 days of exposure. Though not all of the biochar materials tested performed equally, differences could be observed. As a next step, five biochar materials were studied under constant-flow column experiments for a duration of 69 days using real stormwater spiked with PFAS. Results showed that vast differences could be observed for the retention rates of the tested PFAS contaminants, with estimated bed volumes for an 80% breakthrough ranging from, for example, 13–60 for perfluorobutanesulfonic acid and from 4 to 53 for perfluoropentanoic acid. In terms of the PFAS backbone, both the static and dynamic flow experiments highlighted that long-chain PFAS showed stronger sorption onto the biochar surface than short-chain PFAS; however, no relevant impact could be identified in terms of the PFAS functional group. Overall, biochar is emerging as a promising and environmentally friendly approach for removing PFAS from contaminated stormwater.
| Original language | English |
|---|---|
| Article number | e70041 |
| Journal | Remediation |
| Volume | 36 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Sept 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
The authors acknowledge the substantial assistance provided by Marija Lukaric (SLU) during the dynamic flow column test in sample collection, as well as Anna-Karin Dahlberg and Johan Eriksson for their efforts toward funding acquisition and for discussions during the duration of the project. Also, the authors thank the collaborators from the Norwegian Geological Institute, Skanska Sverige (Stockholm, Sweden), as well as the different participants of the Rest-to-Best project for their kind donations of biochar materials. This study was financially supported by the Swedish Research Council for Sustainable Development FORMAS (project number 2020-01107, SAFESTORM) and the project “Residues for best use – Biochar as solution and product in the circular and climate positive society (Rest-to-Best)” funded by the Swedish Innovation Agency (Vinnova) (project number 2021-01589). Aleksandra Skrobonja acknowledges the Ministry of Science, Technological Development and Innovation, Republic of Serbia (Contract number 451-03-66/2024-03/200017). The authors also wish to thank Bio4Energy, a strategic research environment appointed by the Swedish government and the Wallenberg Wood Science Center under the auspices of the Alice and Knut Wallenberg Foundation. This study is also related to the activities of the Johan Gadolin Process Chemistry Centre at Åbo Akademi University. The authors acknowledge the substantial assistance provided by Marija Lukaric (SLU) during the dynamic flow column test in sample collection, as well as Anna‐Karin Dahlberg and Johan Eriksson for their efforts toward funding acquisition and for discussions during the duration of the project. Also, the authors thank the collaborators from the Norwegian Geological Institute, Skanska Sverige (Stockholm, Sweden), as well as the different participants of the Rest‐to‐Best project for their kind donations of biochar materials. This study was financially supported by the Swedish Research Council for Sustainable Development FORMAS (project number 2020‐01107, SAFESTORM) and the project “Residues for best use – Biochar as solution and product in the circular and climate positive society (Rest‐to‐Best)” funded by the Swedish Innovation Agency (Vinnova) (project number 2021‐01589). Aleksandra Skrobonja acknowledges the Ministry of Science, Technological Development and Innovation, Republic of Serbia (Contract number 451‐03‐66/2024‐03/200017). The authors also wish to thank Bio4Energy, a strategic research environment appointed by the Swedish government and the Wallenberg Wood Science Center under the auspices of the Alice and Knut Wallenberg Foundation. This study is also related to the activities of the Johan Gadolin Process Chemistry Centre at Åbo Akademi University.
Keywords
- biochar
- per- and polyfluoroalkyl substances (PFAS)
- physico-chemical characterization
- remediation
- stormwater