Water, which is vital for life, is currently carrying a hidden danger. Tiny synthetic pollutants called per- and polyfluoroalkyl substances (PFAS) are found in rivers and oceans worldwide. There are over 10,000 types of these chemicals, and they have very strong carbon-fluorine bonds that nature cannot break down. They build up in the environment and in people, causing serious health problems like cancer, weaker immune systems, and developmental issues.
For a long time, it seemed impossible to get rid of these "forever chemicals." However, scientists in Germany have now found two extreme methods using physics to destroy them. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf have created two different techniques that use intense heat and electrified gas to clean contaminated water.
The first method uses a process called hydrodynamic cavitation. Contaminated water is forced through a narrow space, creating tiny bubbles. When these bubbles collapse, they produce extremely high temperatures, reaching thousands of degrees Celsius. This intense heat destroys the PFAS molecules. The process also creates reactive hydroxyl radicals that help break down the chemicals faster. Early tests showed about 37 percent of a specific chemical called PFOS was degraded.
The second method uses cold atmospheric plasma with injected gas. This works at normal temperatures. Gas is added to the polluted water, and the toxic molecules attach to the rising bubbles. Plasma at the water's surface then breaks down the PFAS as they reach it. This method almost completely destroyed both long and short types of the chemicals, turning about 35 percent of the trapped fluorine into harmless fluoride salts. However, this method uses a lot of electricity and creates new, unstudied byproducts.
The scientists are now working to make these methods larger and plan to combine them to achieve even better results. This research supports Germany's National Water Strategy and aims to fix pollution caused by humans.