Are UV and AOP Technologies Ready to Tackle PFOS/PFAS Contamination?

In recent years, the environmental and health hazards posed by PFAS, including PFOS, have gained significant attention. Removing these from our water remains very much a challenge.
Posted: Friday, 19 January 2024

Per- and polyfluoroalkyl substances (PFAS), including perfluorooctanesulfonic acid (PFOS) are chemicals commonly found in various industrial and consumer products. Studies have shown that they notoriously remain persistent in the environment and the human body, earning them the nickname "forever chemicals". We took an initial look at the challenge in a 2022 blog, but the quest for effective and sustainable methods to break down PFAS compounds has led to an increasing interest in advanced technologies like Ultraviolet (UV) light and Advanced Oxidation Processes (AOP). Here we look at the technologies and their current challenges towards being able to contribute to a solution in a commercial environment.

The Mechanism of UV and AOP Technologies

Ultraviolet (UV) Light

Ultraviolet light, particularly in the C spectrum (UV-C), is known for its germicidal properties. This spectrum of light has the capability to break chemical bonds, making it a potential tool for degrading complex PFAS molecules. When UV light is absorbed by PFAS compounds, it can initiate photolysis, leading to the breakdown of the carbon-fluorine bond, which is one of the strongest in organic chemistry.

Advanced Oxidation Processes (AOP)

AOPs are characterized by the production of highly reactive species like hydroxyl radicals. These radicals are capable of attacking most organic compounds, including PFAS, leading to their degradation. AOP technologies combine various methods such as UV light, hydrogen peroxide, and sometimes catalysts to enhance the degradation process.   

Current Status of the Technology

Recent studies have shown promising results in using UV and AOP technologies to degrade PFAS compounds. Laboratory-scale experiments have demonstrated significant breakdown of these chemicals under controlled conditions. See the list of relevant sources of studies at the bottom of this blog if you would like to read into this in more depth. However, several challenges remain:

Efficacy at Scale: Scaling these technologies from lab experiments to full-scale environmental remediation remains a challenge. The effectiveness of UV and AOP in varied environmental matrices (like soil, groundwater, etc.) is still under research.

Energy Efficiency: UV and AOP methods can be energy-intensive. Making these processes energy-efficient is crucial for their practical application.

By-product Management: The degradation of PFAS can lead to the formation of smaller, potentially harmful by-products. Better understanding and managing of these by-products are essential for the safe application of the technologies.

Cost: Higher operational costs, primarily due to energy consumption and the need for specialised equipment, currently limit the widespread adoption of these technologies.

Path to Commercial Viability

Research and Development

Ongoing research focusing on optimising UV/AOP systems for different environmental conditions and PFAS types is crucial. This includes developing more efficient catalysts, identifying optimal operational parameters, and integrating these systems with existing water treatment infrastructures.

Regulatory Framework

A clear regulatory framework that outlines acceptable levels of PFAS in the environment and guidelines for remediation technologies can drive innovation and investment in this field is required. This will help provide a clearer direction of travel for companies to invest their time and resources.  

Public-Private Partnerships

Collaborations between governments, research institutions, and private companies can accelerate the development and deployment of these technologies. Funding and resources from these partnerships can be pivotal in overcoming current limitations.

Timeline for Commercialisation

Given the current pace of research and growing regulatory pressures to address PFAS contamination, we could see viable commercial applications of UV and AOP technologies in the next 5-10 years. This timeline could be expedited with increased investment and focused collaborative efforts in this field.


While the complete destruction of PFAS compounds remains a formidable challenge, the advancements in UV and AOP technologies offer a ray of hope. With continued research, innovation, and supportive policy frameworks, these technologies hold the potential to play a critical role in mitigating the PFAS crisis. The journey from laboratory findings to real-world applications is often long and complex, but the environmental and health benefits of successfully tackling PFAS pollution justify the effort and investment required to advance these promising technologies.  


Here are some references to research studies and articles that provide valuable insights into the use of UV and AOP technologies for the degradation of PFAS compounds:

Trojanowicz, M., Bojanowska-Czajka, A., Capodaglio, A. G., et al. (2018). "Advanced oxidation/reduction processes treatment of aqueous solutions contaminated with perfluorinated compounds (PFCs) – A review." Chemical Engineering Journal, 334, 1498-1511. This review article provides a comprehensive overview of various advanced oxidation and reduction processes, including UV-based methods, for the treatment of water contaminated with perfluorinated compounds.

Hori, H., Hayakawa, E., Einaga, H., et al. (2008). "Degradation of Perfluorooctane Sulfonate and Perfluorooctanoic Acid by Advanced Oxidation Processes." Environmental Science & Technology, 42(13), 4976-4981. This study investigates the degradation of PFOS and PFOA using various advanced oxidation processes, highlighting the effectiveness and challenges of these methods.

Park, S., Lee, L. S., Medina, V. F., et al. (2016). "Degradation of Perfluorooctanesulfonic Acid by Reactive Species Generated Through Catalyzed H2O2 Propagation Reactions." Environmental Science & Technology Letters, 3(2), 38-42. This research explores the degradation of PFOS using catalyzed hydrogen peroxide propagation reactions, a subset of AOP, and discusses the potential of these reactions in PFAS treatment.

Vecitis, C. D., Park, H., Cheng, J., et al. (2009). "Treatment Technologies for Aqueous Perfluorooctanesulfonate: A Critical Review Including Incentives and Practicalities of Using High-Energy Electrons and Pulsed Power." Environmental Science & Technology, 43(23), 7048-7056. This critical review discusses various treatment technologies, including high-energy electrons and pulsed power (aspects of AOP), for aqueous PFOS remediation.

Rayaroth, M. P., Aravind, U. K., Aravindakumar, C. T. (2017). "AOPs and RFPS for the Degradation of PFOA and PFOS in Water: A Review." Reviews in Environmental Science and Bio/Technology, 16, 429-454. This review focuses on the application of advanced oxidation and reduction processes for the degradation of PFOA and PFOS in water, emphasizing the progress and challenges in the field.

Appleman, T. D., Higgins, C. P., Quiñones, O., et al. (2014). "Treatment of Poly- and Perfluoroalkyl Substances in U.S. Full-Scale Water Treatment Systems." Water Research, 51, 246-255. This study examines the effectiveness of full-scale water treatment systems, including AOPs, in removing PFAS compounds from water, providing insights into the practical application of these technologies.

These references offer a mix of review articles and specific studies, providing a broad understanding of the current state of research and the challenges in using UV and AOP technologies for PFAS degradation. They serve as excellent starting points for a deeper exploration into the subject.


Other News stories you may like...