The significance of fluorinated compound chain length, treatment technology, and influent composition on per- and polyfluoroalkyl substances removal in worldwide wastewater treatment plants

摘要

Wastewater treatment plants (WWTPs) are deemed major conveyors and point sources of per‐ and polyfluoroalkyl substances(PFAS) to the environment. This statistical meta‐analysis of existing literature from the past 15 years focused on thesignificance of treatment type for PFAS removal efficiencies and the influence of PFAS sources (domestic vs. industrial) ontheir removal. Different sampling events, WWTPs across the world, different treatment technologies, configurations, andprocesses, as well as different PFAS classes and compounds were considered. This study evaluated 13 PFAS analyzedpredominantly in 161 WWTPs across the world. The statistical test results revealed that these 13 frequently detected andreported PFAS can be divided into four groups based on their behavior during wastewater treatment, namely (1) C6–10perfluorocarboxylic acids (PFCAs), (2) C4,5,11,12 PFCAs, (3) C4,6,8 perfluoroalkane sulfonic acids (PFSAs), and (4) C10 PFSA.In this study, biological treatments such as (1) membrane bioreactors, (2) combination of two or more biological treatments,and (3) biofilm processes revealed the highest PFAS removals, although the addition of a tertiary treatment actually had anonbeneficial effect on PFAS removal. Moreover, a strong statistical correlation was observed between industrial wastewatersources and the presence of high influent PFAS concentrations in the receiving WWTPs. This indicates that industrial sourceswere the main contributors of the PFAS load in the analyzed WWTPs.