Occurrence and partitioning behavior of perfluoroalkyl acids in wastewater effluent discharging into the Long Island Sound.

ABSTRACT

Perfluoroalkyl acids (PFAAs) were measured in aqueous and suspended particulate matter (SPM) fractions in the final effluents from 12 wastewater treatment facilities located around the Connecticut shoreline. Aqueous phase concentrations ranged from 53 to 198 ng/L for ∑PFAAs with ≤7 perfluorinated carbons (CF2) and 2-73 ng/L for >7 CF2 PFAAs. Predominant PFAAs associated with effluent derived SPM were perfluorodecanoic acid and perflurorooctane sulfonic acid, detected in 48% and 52% of samples in concentrations ranging from Sound (LIS), average total annual PFAA mass loads from wastewater treatment facilities to the LIS is estimated in the range of 70-315 kg/year, with 4-100 kg/year consisting of >7 CF2 PFAAs. Partitioning coefficients (log KOC) derived for effluent water and SPM phases (4.2 ±â€¯0.3, 4.4 ±â€¯0.4, 5.1 ±â€¯0.2 and 5.3 ±â€¯0.2 for PFOA, PFNA PFDA and PFUnA; 4.5 ±â€¯0.2 and 5.2 ±â€¯0.2 for PFOS and PFHsX respectively) were found to be of similar magnitude to aeration tank particles, though 0.5 to 2 log units greater than sludge solids and to natural system particulates including riverine SPM, estuarine SPM and sediments. Results from this study suggest that effluent derived suspended particulate matter could be an effective vector in the transport of long-chained PFAAs through wastewater treatment into receiving waters, and a potential vector to the local food chain.