Fluorescence-Based Approach for Monitoring Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) During Granular Activated Carbon (GAC) Adsorption

This study explores the GAC adsorption of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), that stands out as the most frequently produced and detected compounds belonging to the class of poly- and perfluoroalkyl substances (PFAS). Experiments were performed on three distinct wastewaters (WW-1, WW-2, WW-3) employing rapid small scale column tests (RSSCTs). RSSCTs were carried out at the same empty bed contact time (EBCT) using a commercially available GAC. Parallel factor analysis (PARAFAC) was used to deconvolute fluorescence EEMs. Four independent PARAFAC components were found. High linear correlations were found between the PFAS breakthrough and the breakthrough of the PARAFAC components during the GAC process for WW-1, WW-2 and WW-3. In particular, the PARAFAC component C3, representative of the protein tryptophan-like fluorescence region, lead to high accuracy prediction models of PFOA and PFOS breakthough.