Biochar sorption of perfluoroalkyl substances (PFASs) in aqueous film-forming foams-impacted groundwater: Effects of PFASs properties and groundwater chemistry

Hoang Nhat Phong Vo; Thi Minh Hong Nguyen; Huu Hao Ngo; Wenshan Guo; Pradeep Shukla

doi:10.1016/j.chemosphere.2021.131622

Biochar sorption of perfluoroalkyl substances (PFASs) in aqueous film-forming foams-impacted groundwater: Effects of PFASs properties and groundwater chemistry

Chemosphere. 2022 Jan;286(Pt 1):131622. doi: 10.1016/j.chemosphere.2021.131622. Epub 2021 Jul 21.

Authors

Hoang Nhat Phong Vo¹, Thi Minh Hong Nguyen², Huu Hao Ngo³, Wenshan Guo⁴, Pradeep Shukla²

Affiliations

¹ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia; Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, 20 Cornwall Street, Woolloongabba, Queensland, 4102, Australia.
² Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, 20 Cornwall Street, Woolloongabba, Queensland, 4102, Australia.
³ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia. Electronic address: ngohuuhao121@gmail.com.
⁴ Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia.

PMID: 34303903
DOI: 10.1016/j.chemosphere.2021.131622

Abstract

The widespread use of per- and polyfluoroalkyl substances (PFASs)-related products such as aqueous film-forming foams (AFFF) has led to increasing contamination of groundwater systems. The concentration of PFASs in AFFF-impacted groundwater can be several orders of magnitude higher than the drinking water standard. There is a need for a sustainable and effective sorbent to remove PFASs from groundwater. This work aims to investigate the sorption of PFASs in groundwater by biochar column. The specific objectives are to understand the influences of PFASs properties and groundwater chemistry to PFASs sorption by biochar. The PFASs-spiked Milli-Q water (including 19 PFASs) and four aqueous film-forming foams (AFFF)-impacted groundwater were used. The partitioning coefficients (log K_d) of long chain PFASs ranged from 0.77 to 4.63 while for short chain PFASs they remained below 0.68. For long chain PFASs (C ≥ 7), log K_d increased by 0.5 and 0.8 for each CF₂ moiety of PFCAs and PFSAs, respectively. Dissolved organic matter (DOM) was the most influential factor in PFASs sorption over pH, salinity, and specific ultraviolet absorbance (SUVA). DOM contained hydrophobic compounds and metal ions which can form DOM-PFASs complexes to provide more sorption sites for PFASs. The finding is useful for executing PFASs remediation by biochar filtration column, especially legacy long chain PFASs, for groundwater remediation.

Keywords: AFFF; Biochar; DOM; Groundwater; PFASs; Sorption.

MeSH terms

Charcoal
Fluorocarbons* / analysis
Groundwater*
Water
Water Pollutants, Chemical* / analysis

Substances

Fluorocarbons
Water Pollutants, Chemical
biochar
Water
Charcoal