Removal of PFAS from wastewater by bio-waste adsorbent: material characterization and adsorption kinetic study

Per- and polyfluoroalkyl substances (PFAS) are considered emerging contaminants and have been increased their attention due to their distribution in water body. These compounds are acid and characterized by a thermal stability to make them resistant to degradation processes. Activities such as tannery, paper and cardboard production, waterproof cloths, produce wastewater rich in PFAS and heavy metals. There are currently no Maximum Contaminant Levels established for PFAS chemicals and the Environmental Protection Agency is working on the definition of a technical guidance providing information on health effects and methods for the treatment of drinking water. The adsorption process is one of the technologies used for the treatment of wastewater and food residues are getting increased attention as bio-adsorbent because they can be found easily as wastes or by-products and at almost no cost. In this work the removal of PFAS was performed by using food waste such as Yerba Mate (YM) as bio-adsorbent. Adsorption tests were performed at different pH condition (from 3 to 10) and temperature (from 10 °C to 40 °C). The concentration of pollutants was determined by HPLC, UV-VIS and TOC analysis. SEM-EDS, XRD, FT-IR and BET were done to achieve a characterization of the adsorbent material.