Investigation on Per- and Poly-Fluoroalkyl Substances Sources and Removal in a Municipal Wastewater Treatment Plant

PFAS (per- and poly-fluoroalkyl substances) is a complex family of manmade highly fluorinated aliphatic organic chemicals including thousands of chemical structures identified. A research was carried out at a municipal wastewater treatment plant (MWWTP) in Northern Italy to define the inflowing load of PFAS, the main load sources and the removal efficiency of the treatment processes. Then, the 100 industrial settlements served by the MWWTP were examined, and 8 of them were selected as potential PFAS sources. The calculated loads summed up to 98.5 % of the total load entering the plant. The removal in the WWTP was null and, in some cases, negative. As also reported in the literature some precursors can be transformed in PFAS during the biological process and some sludge accumulated compounds can be released.