Reviewed by Danielle Ellis, B.Sc.Oct 7 2024
Researchers from Oxford Brookes University have created a brand-new device known as a hydrodynamic reactor to address one of the toxic substances in the world's water supplies. The reactor makes use of cavitation to form and collapse bubbles as a result of pressure fluctuations. The “forever chemicals,” or per and poly-fluoroalkyl compounds that are harmful to aquatic life, are eliminated by the reactor. The Chemical Engineering Journal published the study.
Convenience items like stain-resistant carpeting, pizza boxes, nonstick cookware, and waterproof clothes are made using PFAS chemicals, which were created in the 1930s. Scientists validated the toxicity of these substances, which were first reported in the 1970s and early 2000s.
It has been discovered that they pose a health risk and have contaminated water sources across the globe. Diseases like ulcerative colitis, thyroid issues, high cholesterol, liver damage, and cancer are linked to the substances.
The elimination of PFAS compounds from water sources is a worldwide undertaking. They are discharged into water sources through industrial wastewater, contaminated product landfills, domestic wastewater, sewage, and agricultural runoff.
Once contaminated water is released into rivers, lakes, and seas, it eventually infiltrates our public water supplies, including our domestic drinking water. Our challenge has been to find a way of effectively treating water to remove PFAS chemicals sustainably and at a scale.
Iakovos Tzanakis, Professor and Research Lead, Engineering Materials, Oxford Brookes University
The Royal Society of Chemists in the UK has started a campaign to reduce PFAS in water sources. The EU intends to impose new regulations on the use of PFAS chemicals in 2024. To safeguard public safety, legally binding PFAS limits have also been set in America.
Until now, methods of removing PFAS from water have been costly and time-consuming using chemicals and restricted to laboratory scale. But the research I have carried out with my colleague Dr. Morteza Ghorbani has identified a potential solution.
Iakovos Tzanakis, Professor and Research Lead, Engineering Materials, Oxford Brookes University
To develop and test the hydrodynamic cavitation reactor, Professor Tzanakis and Dr. Ghorbani, a Royal Society-Newton Fellow at Oxford Brookes, worked in conjunction with Sabanci University (Turkey), white goods manufacturer Beko (Turkey), KTH Royal Institute of Technology (Sweden), and IVL Swedish Environmental Research Institute.
The reactor produces and bursts a large number of tiny bubbles using quickly flowing liquid in confined places, which aids in cleaning the water.
Professor Tzanakis said, “This technology has the potential to revolutionize wastewater treatment, making it safer and more sustainable for communities around the globe. The advancements in green hydrodynamic cavitation provide a scalable alternative to current methods, overcoming its limitations.”
The hydrodynamic cavitation reactor, which is energy-efficient and environmentally benign, performed significantly better than anticipated during testing at the Hammarby Sjöstad wastewater treatment plant in Sweden.
In just 30 minutes, the reactor was able to degrade 11 prevalent PFAS variations at a rate of about 36%, without the need for additional chemicals.
The results were impressive. We did not expect that level of PFAS processing in such a short space of time. We are now exploring the fundamental mechanisms of PFAS removal in depth at Oxford Brookes University to better control and optimize the process.
Dr. Morteza Ghorbani, Royal Society-Newton Fellow, Oxford Brookes University
Dr. Ghorbani said, “Our next step is scaling up our reactor to treat larger volumes of wastewater containing PFAS. We are aiming to treat wastewater containing PFAS volumes up to 20 liters. The reactor for this has already been built. After that, our target is to treat volumes up to 200 liters in a wastewater treatment plant in Sweden.”
Dr. Ghorbani continued, “Our goal is to boost this promising approach by unveiling the intricate physics that drive the technology through the use of various reactors in different countries. We want to ensure this technology is ready for actual wastewater treatment in the near future and as set by the EU 2035 strategy when all PFAS-containing waste must be treated.”
Journal Reference:
Talabazar, R. F., et al. (2024) Removal of per- and polyfluoroalkyl substances (PFAS) from wastewater using the hydrodynamic cavitation on a chip concept. Chemical Engineering Journal. doi.org/10.1016/j.cej.2024.153573.