GRAND RAPIDS, Mich. (WOOD) — A team of researchers from California has found a new technique for breaking down PFAS — one that uses less energy and destroys the chemical compounds instead of simply stripping them from other material.
Haizhou Liu, an associate professor of chemical and environmental engineering at the University of California-Riverside, led the study that was published in November in the Journal of Hazardous Materials Letters. He explained to News 8 that the technique uses hydrogen and ultraviolet light to break down the chemicals.
“The concept is similar to what you would receive with sunlight. Sunlight excites water. We use water as the main reactive chemicals,” Liu said. “We think about light. It’s basically a form of energy. If you think about when we give energy to water. One example is you boil the water, you heat it up, and it turns into bubbles, right? That’s the form of energy in that water. Water gets excited. In this case, we shine light on water and when the water receives the light energy it gets excited. It turns itself into a catalyst that reacts very strongly with PFAS and breaks them apart.”
Liu says that early experiments were very promising, destroying nearly 100% of the PFAS chemicals in the test. He’s also excited because this technique uses far less energy and doesn’t result in any secondary pollutants.
“We are not just talking about separating PFAS into a second medium, because existing treatments mostly use carbon as an absolvent or a different media to absorb PFAS from water, from contaminated wastewater, into a secondary solid waste. You still have to dispose of the secondary waste. It’s not really destroyed,” Liu told News 8.
Liu is referring to techniques like mechanochemical treatments and pyrolysis, which can separate PFAS from solids. Another called super-critical water oxidation can break down PFAS compounds using intense pressure and temperature, but it requires much more energy that this new technique.
The chemical breakdown from the UV light destroys the PFAS and converts it into fluoride iron, the same additive commonly used to protect teeth and prevent dental cavities.
Liu said the next steps of his team’s research will focus on building a prototype and how to use it in various situations.
“In terms of the science, I think we understand it pretty well,” he said. “Our ongoing efforts are focused on building the prototype and make it applicable for different types of source water. We talk about there could be private wells on ground water, which has a very different chemistry in comparison to landfill leachate. We are fine-tuning those treatment parameters to make it very effective across different treatment scenarios.”
PFAS — or per- and polyfluoroalkyl substances — is a giant group of chemical compounds that were first developed in the 1940s and incorporated into all sorts of products for its waterproofing and heat resistant properties. However, decades later, research showed that PFAS compounds do not organically break down and can build up in the human body, causing serious health problems including cancer.
Because it was so widely used and is still manufactured today and because it doesn’t break down naturally, PFAS has become a major pollutant. Products containing PFAS can end up in landfills can leech into groundwater and spread into communities. PFAS can also be passed through tainted water that is used on crops or livestock and is passed on in food.
A national study conducted between 2011 and 2012 estimated that 97% of all Americans have some trace of PFAS in their blood.