Effectiveness of pitcher and bottle filters to remove poly- and perfluoroalkyl substances (PFAS) from drinking water

The occurrence of poly- and perfluoroalkyl substances (PFAS) in drinking water poses significant health risks. In this study the effectiveness of 12 popular pitcher and 5 bottle filters in removing 25 fluorinated contaminants from drinking water was evaluated. Twenty individual PFAS, outlined in Drinking Water Directive 2020/2184 as "Sum of PFAS" and 5 emerging PFAS, were considered. The average efficiency of PFAS removal by the tested filters ranged from 31 % to 99 % for the sum of 20 legacy compounds, and from 19 % to 99 % for emerging ones. Over 80 % reduction was recorded for 9 tested filters. In most examined cases, the filter efficiency increased with alkyl chain length for both perfluorinated carboxylic and sulfonic acids. Four filters were found to reduce the concentration of Σ₂₀PFAS from 2000 ng/L to <100 ng/L, meeting the Directive's limit. Additionally, the best filtration bed decreased the sum of PFAS from 100 ng/L to <6 ng/L for model water and from 25 ng/L to 0.6 ng/L for real water, indicating ≥94 % removal efficiency in both cases. The Brunauer-Emmett-Teller (BET) surface area (S_BET) and micropore volume were key factors influencing PFAS removal efficiency in the pitcher filter. The obtained results highlight important information regarding drinking water quality and safety.