Per- and polyfluoroalkyl substances (PFAS) are a general classification of over 3000 unique variations of various fluorinated alkyl compounds. PFAS are found in a wide variety of everyday industrial and household products. These substances are man-made and do not occur naturally in the environment. In North America, no specific guidelines have been put into place for the disposal of PFAS-based materials, and because of this, at the end of their lifecycle, they are typically discarded into landfills. As these materials gradually break down, they are released into landfill leachate, and as these materials travel through the rainwater into rivers and streams, they eventually enter and accumulate in various water sources, including those from which drinking water is obtained. As this PFAS-contaminated water is consumed, a bioaccumulation can occur which can lead to various types of serious illnesses and ailments. Among the over 3000 variations of PFAS molecules, perfluorooctane sulfonic acid (PFOS) is one of the most prevalent and difficult to remove. Due to the potential health risks that an accumulation of PFOS in drinking water can pose, along with the general environmental risks, a water treatment process designed to remove or decrease the concentration of PFOS in drinking water is a topic of severe importance and a crucial area of research.
In this research, an experimental procedure has been designed and evaluated in which Perfluorooctanesulfonic acid (PFOS) has been photolytically degraded. Nanofiber composite with Fe(III) and polyvinylidene fluoride (PVDF) was fabricated by electrospinning and characterized with TGA, XRD, SEM, and AFM. The nanofiber composite successfully degraded Perfluorooctanesulfonic acid (PFOS) in aqueous medium and in the presence of UVC light. It was observed that the presence of hydrogen peroxide increases the rate of the reaction. It is suggested that PFOS binds with Fe(III) and a free radical was generated associated with PFOS molecule. The free radical is further degraded to smaller molecular fragments in the presence of UVC light. The study investigated the rate of PFOS degradation as a function of time, concentration of PFOS and hydrogen peroxide, and number of composite mats. The results demonstrated Fe(III)/PVDF nanofiber composite can potentially be used for PFAS removal.
