Longitudinal assessment of point‐of‐use carbon filters for removal of per‐ and polyfluoroalkyl substances from private well water

Abstract

Eighteen private well users in North Carolina were recruited to test the performance of under-sink, activated carbon block water filters to remove per-and polyfluoroalkyl substances (PFAS). Monthly sampling was conducted for 8 months. Filters were certified for removal of perfluorooctanoic acid and perfluorooctanesulfonic acid under NSF International certification P473, but not for additional short-chain perfluoroalkyl acids or perfluoroalkyl ether acids (PFEAs) evaluated in this study. Out of 47 targeted analytes, 17 PFAS were detected in filter influent samples (influent P PFAS 4.7-131 ng/L). Mixed-effects Tobit regression models showed that the filters effectively removed 97%-99% of all influent PFAS, including short-chain PFEAs, for the entire manufacturer-recommended lifetime of the device. The prevalence of PFAS above the minimum reporting limits was reduced by 99.5%, and the prevalence of any PFAS above the method detection limits was reduced by 92%. The results provide increased confidence in NSF P473-certified filters for the removal of PFAS from private well water.activated carbon, PFAS, point-of-use water treatment, private wells | INTRODUCTIONPer-and polyfluoroalkyl substances (PFAS)-including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs) (together referred to as perfluoroalkyl acids (PFAAs)), and replacement perfluoroalkyl ether acids (PFEAs)-have generated concern in recent decades for their widespread environmental

Performance of pitcher-type POU filters for the removal of 75 PFAS from drinking water: comparing different water sources

“…A total of 17 PFAS were found in filter influent samples out of 47 targeted analytes ( PFAS 4.7-131 ng/L). Overall, results showed that the filters effectively removed PFAS (97%-99%) in all influents, including short-chain PFEAs, for the total producerrecommended lifetime of the filters (Mulhern et al, 2021).…”

PFAS are forever? The state of the science and research needs for analyzing and treating PFAS‐laden water

“…Also at the home system scale, Mulhern et al (2021) show that in a study of 18 private wells in North Carolina, a commercially‐available point of use (POU) carbon‐block filter certified under NSF's P‐473 protocol for PFOA and PFOS was successful in removing 17 PFAS detected in the filter influent, including short‐chain perfluoroalkyl ether acids (PFEAs). The eight‐month study covered the manufacturer's recommended lifetime for the device.…”

A Participatory Science Approach to Evaluating Factors Associated with the Occurrence of Metals and PFAS in Guatemala City Tap Water

“…Samples were received at RTI on 1 April 2021 and analyzed for a panel of 20 metals (Table S1) and 25 PFAS (Table S2) according to methods approved by the U.S. Environmental Protection Agency (EPA). The fully specified conditions for both methods have been described in detail previously [36,37].…”