Given the ubiquitous detection of per- and polyfluoroalkyl substances (PFAS) within numerous soil and water environmental compartments, there is a need for global understanding of current methodologies for extracting water, solids, polar organic chemical integrative samplers (POCIS), and plant tissue for these substances. This study provides details of several current extraction methods, demonstrates the use of POCIS in monitoring these compounds in a wastewater environment, and provides evidence of detectable levels of certain PFAS compounds within Midwestern municipalities and agroecosystems. Validated extraction procedures help characterize occurrence and release of 18 PFAS in a midwestern wastewater treatment plant (WWTP), surface water, runoff after land application of biosolids to agricultural test plots, infiltration into topsoil, and uptake by grain sorghum. Of the compounds measured, 14 PFAS were detected at least at one sampling site or type. The average total (Σ PFAS) dissolved phase time-weighted average (TWA) concentration in wastewater influent, effluent and in the upstream and downstream effluent mixing zone (EMZ) sites in the receiving stream, respectively, were 27.9, 132, 37.7, and 71.4 ng L−1. Long-chain PFAS dominated most of the aqueous compartments, and perfluoroalkyl acids (PFAAs) occurred in the WWTP and receiving surface waters. Total Σ14 PFAS measured in municipal biosolids applied to soils were 22.9 ng g−1 dw with long-chain PFAS comprising 77.5% of the cumulative PFAS mass. Perfluorooctanesulfonic acid (PFOS) was the most abundant compound detected in biosolids at the highest concentration (9.40 ng g−1 dw). Accumulation in WWTP biosolids was estimated to occur at a rate of 72.8 g day−1 dw based on the difference between influent and effluent time weighted average concentrations. PFAS were detected in both surface soil and runoff after land application of biosolids, but also in control plots consistent with background PFAS contamination. PFAS concentrations in surface runoff decreased over time from plots treated with biosolids. These results provide evidence of the introduction of PFAS to agroecosystems from wastewater effluent and land application of biosolids in the Midwest.
Bibliographical noteFunding Information:
The work done in this research study was supported in majority by the United States Geological Survey (USGS) by the USGS 104(b) Grant (No. 2020NE186B) for the 2020-2021 school year obtained by DS, TM, and SB-H.
The authors would like to thank the WWTP for access to the wastewater sources, discharge data, and biosolid production data. A special thanks to the Water Sciences Laboratory for access to laboratory equipment utilized to extract and analyze PFAS from complex matrices.
Copyright © 2022 Caniglia, Snow, Messer and Bartelt-Hunt.
- agricultural ecosystems
- surface waters
- wastewater treatment plant
ASJC Scopus subject areas
- Water Science and Technology