Abstract

The global problem of contamination of drinking water sources and the aquatic environment with per- and polyfluoroalkyl substances (PFASs) originating from highly contaminated soils is addressed in this study. For the first time, a colloidal activated carbon (AC) product (PlumeStop (R)) was systematically assessed for PFASs stabilization in soil. Colloidal (particle size 0.1-1.1 mu m) AC has the advantage that field application is non-intrusive, comprising injection under high pressure in situ at PFAS-contaminated soil hotspots. In the assessment, 10 different soil mixtures with gradually increasing organic carbon and clay fractions were spiked with 18 different PFASs of varying perfluorocarbon chain length and four different functional groups and aged for one year. Equilibrium leaching tests showed that the ability of colloidal AC to increase sorption of PFASs to soil was highly dependent on PFAS perfluorocarbon chain length. The best treatment efficiency was observed for perfluorocarbon chain lengths 6-7 at which colloidal AC resulted in sorption of 81%, 85%, and 86% for perfluorooctanoate (PFOA), 6:2 fluorotelomer sulfonate (6:2 FTSA) and perfluorohexane sulfonate, (PFHxS), respectively. Sorption of individual PFASs decreased significantly (p < 0.05) with increasing organic carbon content in soil treated with colloidal AC indicating stearic hindrance of the ACs pore structure. On the other hand, the sorption of the majority of PFASs increased significantly (p < 0.05) with increasing clay content in colloidal AC-treated soil, which can be explained by increase in surface area that colloidal AC can sorb to. Overall, the results indicate that the colloidal AC product tested can be useful in remediation approaches for certain PFASs under specific field conditions and PFAS contamination.

Published in

Journal of Environmental Management
2019, Volume: 249, article number: 109345
Publisher: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD

SLU Authors

• Sörengård, Mattias

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Ahrens, Lutz

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all
Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1016/j.jenvman.2019.109345

Permanent link to this page (URI)

https://res.slu.se/id/publ/102604