ez0c00004_si_001.pdf (605.57 kB)
Assessing the Effectiveness of Point-of-Use Residential Drinking Water Filters for Perfluoroalkyl Substances (PFASs)
journal contribution
posted on 2020-02-05, 13:34 authored by Nicholas
J. Herkert, John Merrill, Cara Peters, David Bollinger, Sharon Zhang, Kate Hoffman, P. Lee Ferguson, Detlef R. U. Knappe, Heather M. StapletonPer- and polyfluoroalkyl
substances (PFASs) have come under increased
scrutiny due to concerns about their potential toxicity and prevalence
in the environment, particularly drinking water. PFASs are difficult
to remove in full-scale water treatment systems because of their physicochemical
properties. Here we evaluated the effectiveness of point-of-use (POU)
and point-of-entry (POE) residential drinking water filters in removing
a suite of three perfluoroalkyl sulfonic acids, seven perfluoroalkyl
carboxylic acids, and six per- and polyfluoroalkyl ether acids in
homes in central (n = 61) and southeastern (n = 12) North Carolina. POU systems included countertop
and pitcher filters, faucet-mounted filters, activated carbon block
refrigerator filters, activated carbon block under-sink filters, under-sink
dual-stage filters, and under-sink reverse osmosis filters. All under-sink
dual-stage and reverse osmosis filters tested showed near complete
removal for all PFASs evaluated. In contrast, all other filters containing
activated carbon exhibited variable PFAS removal. In these filters,
PFAS removal efficiency was dependent on chain length, with long-chain
PFASs (∼60–70% removal) being more efficiently removed
than short-chain PFASs (∼40% removal). A few whole-house activated
carbon POE systems (n = 8) were also evaluated; however,
results were variable, and in some cases (four of eight systems),
increased PFAS levels were observed in the filtered water.