Destruction of PFAS using High Frequency Power Ultrasound

R. Marsh
New Jersey Institute of Technology, United States

Keywords: PFAS, ultrasound, sonochemistry, emerging contaminants

The widespread use of material containing per- and polyfluoroalkyl substances (PFAS) in consumer and industrial products has led to the detection of significant concentrations of these compounds in the human body. The unique properties of PFAS are environmental persistence, adverse health effects, and resistance to various removal methods. In this research, ultrasound is used to degrade PFAS in water. The high frequency power ultrasound creates free radicals that are potent oxidizing agents. The destruction of PFAS using free radicals is an emerging advanced oxidation technology that has been shown to treat a wide variety of organic compounds in aqueous solutions. For this study, the sonochemical degradation of two common PFAS, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), was performed using two different configurations to produce an ultrasonic field, a horn-type transducer operating at 20 kHz and a plate type transducer operating between 200 – 800 kHz. The 20 kHz transducer provides agitation, breaks up clusters of molecules, and increases the number of bubbles in solution. The high frequency ultrasound produces hydroxyl radicals which oxidize and degrade organic compounds in suspension. Initial results showed high destruction rates of both PFOS and PFOA.