Removal and release of microplastics and other environmental pollutants during the start-up of bioretention filters treating stormwater
Journal article, 2024

Untreated stormwater is a major source of microplastics, organic pollutants, metals, and nutrients in urban water courses. The aim of this study was to improve the knowledge about the start-up periods of bioretention filters. A rain garden pilot facility with 13 bioretention filters was constructed and stormwater from a highway and adjacent impervious surfaces was used for irrigation for ∼12 weeks. Selected plants (Armeria maritima, Hippophae rhamnoides, Juncus effusus, and Festuca rubra) was planted in ten filters. Stormwater percolated through the filters containing waste-to-energy bottom ash, biochar, or Sphagnum peat, mixed with sandy loam. Influent and effluent samples were taken to evaluate removal of the above-mentioned pollutants. All filters efficiently removed microplastics >10 µm, organic pollutants, and most metals. Copper leached from all filters initially but was significantly reduced in the biochar filters at the end of the period, while the other filters showed a declining trend. All filters leached nutrients initially, but concentrations decreased over time, and the biochar filters had efficiently reduced nitrogen after a few weeks. To conclude, all the filters effectively removed pollutants during the start-up period. Before being recommended for full-scale applications, the functionality of the filters after a longer period of operation should be evaluated.

Toxic trace metals

Road runoff

Tyre and road wear particles

Ash

Bioretention

Rain garden

Biochar

Microplastics

Sphagnum peat

Author

Glenn Johansson

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Karin Karlfeldt Fedje

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Renova

Oskar Modin

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Marie Haeger-Eugensson

COWI A/S

Wolfgang Uhl

COWI A/S

Yvonne Andersson-Sköld

The Swedish National Road and Transport Research Institute (VTI)

Chalmers, Architecture and Civil Engineering

Ann-Margret Hvitt Strömvall

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Journal of Hazardous Materials

0304-3894 (ISSN) 18733336 (eISSN)

Vol. 468 133532

Innovative Rain Gardens for Sustainable and Effective Treatment of Urban Runoff Polluted with Microplastics, Organic Pollutants and Metals

Åke och Greta Lissheds stiftelse (2023-00215), 2023-05-31 -- 2024-06-30.

COWI A/S, 2022-01-01 -- 2024-12-31.

Formas (2020-01123), 2021-01-01 -- 2023-12-31.

Subject Categories

Water Engineering

DOI

10.1016/j.jhazmat.2024.133532

PubMed

38387172

More information

Latest update

3/8/2024 9