Sorption of organic pollutants frequently detected in stormwater: evaluation of five potential sorbents

ABSTRACT

Adsorption filtration is one of the most promising techniques for removal of dissolved, colloidal and particulate pollutants from stormwater. The aim of this study was to compare the capacity of five filter materials – cellulose, chitosan, chitosan-covered bark, pine bark and polypropylene/polyethylene (PP/PE) fibres – to sorb organic pollutants frequently detected in stormwater, including polycyclic aromatic hydrocarbons (PAHs), alkylphenols and phthalates. In batch tests, synthetic stormwater spiked with a mixture of the organic compounds was contacted with the materials for up to 24 h. The compounds were then liquid–liquid extracted and analysed using GC-MS. Cellulose and chitosan showed very low sorption capacity for the organic contaminants, whereas >70% of the initial concentration of most tested compounds was removed using PP/PE fibres, and >80% with pine bark and chitosan-covered bark. The highest adsorption capacity was found for PAHs (up to 44 µg/g) using PP/PE fibres and bark. For all tested compounds, maximum sorption was approached within 30 min using these materials.

KEYWORDS:

• Adsorption filter
• priority pollutants
• stormwater treatment
• waste materials
• wood-based media

Acknowledgements

The authors sincerely thank Erik Bick at Rent Dagvatten for supplying the materials, and Paula Parkinson and Tim Ma for their laboratory assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Karin Björklund http://orcid.org/0000-0002-9585-5751

Additional information

Funding

This work was supported by the Sweden-America Foundation; the Carl Tryggers Stiftelse för Vetenskaplig Forskning [grant number CTS 12:60]; and the Swedish Research Council Formas [grant number 245–2012–1607].