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 ΣPFAS 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) 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.