Assessment of the contribution of Advanced Oxidation Processes (AOPs) to the degradation of per- and polyfluoroalkyl substances (PFAS) in aqueous media

Many studies have shown that UV radiation promotes advanced oxidation processes(AOPs) that degrade perfluoroalkyl substances(PFAS) and that UV radiation is required for accelerating and enhancing the degradation process of our contaminant. The primary objective of this Thesis was to assess the contribution of each of these processes individually for fluorinated compound removal from water, focusing on perfluorooctanoic acid (PFOA). This review systematically evaluates various potential pathways developed to degrade PFAS through Persulfate activation, Heterogeneous Photocatalysis, and Photo-Fenton reactions as well as employing Metal-Organic frameworks (MOFs) for degrading pollutant species. The membranes used in the experimental tests are made of polyimide, a polymer well known for its excellent chemical and physical properties, it provides good performance even at high temperatures and high resistance to irradiation with UV without negative impact providing as support for the catalyst which is Tetrabutyl Titanate (TBT). During the Electrospinning, there are various parameters need to be controlled to prepare a proper membrane, one of the most important one could be the support solution viscosity, it has to stay within its production-efficient range for making fibers. The membranes have been characterized by several analyses: Fourier-transformed infrared spectroscopy(FT-IR), to confirm that the imidation process occurs, thermo-gravimetric analysis (TGA), to determine the amount of TiO2 in the membranes, and environmental scanning electron microscope (ESEM), to analyze the nanostructure of the membrane in order to determine the diameter of the fibers if they are in the proper size for capturing PFOA molecules. According to the experiments, it is necessary to prepare two types of membranes, one with catalyst, one without, to establish role of catalyst in the degradation. HPLC analyses also were performed to determine the specific contribution involved in the removal of PFOA. By using these HPLC data, we can then derive the deflourination corresponding to each advanced oxidation process.