3D-printed monoliths remove forever chemicals from water.

Harmful ‘forever chemicals’ can be removed from water with 3D printed ‘monolith’ structures made from ink infused with indium oxide.

The team at Bath University said its method, using monoliths (ceramic-infused lattices), removes at least 75 per cent of perfluorooctanoic acid (PFOA), one of the most common perfluoroalkyl and polyfluoroalkyl substances (PFAS), from water, and could become an important tool in future efforts to eliminate the chemicals from water supplies.

Their findings are detailed in The Chemical Engineering Journal.

Known as forever chemicals due to the long time they take to break down, PFAS are man-made and known to cause health issues including harm to reproductive, developmental, and cardiovascular systems, as well as increasing the likelihood of diabetes.

Sources of PFAS include domestic products, often with water-repellent properties, such as non-stick pans, raincoats, paints, fabrics and firefighting foams.

In a statement, Dr Liana Zoumpouli, a Research Associate in Bath’s Department of Chemical Engineering and a member of the Centre for Digital, Manufacturing and Design, said: “PFAS, or ‘forever chemicals’, are a major focus in water treatment and public health. We have created an efficient way to remove these chemicals from water without using lots of energy.

“Using 3D printing to create the monoliths is relatively simple, and it also means the process should be scalable. 3D printing allows us to create objects with a high surface area, which is key to the process. Once the monoliths are ready you simply drop them into the water and let them do their work. It’s very exciting and something we are keen to develop further and see in use.”

The US and EU have brought in some rules on acceptable levels of PFAS and similar chemicals in drinking water, but the researchers said further legislation is likely as the scale of health threats comes into clearer focus.

Co-author Professor Davide Mattia said: “Currently, these chemicals are not strongly regulated in the UK in drinking water, but there are guidelines, and we expect changes in policy quite soon. Water companies are likely to be looking at integrating systems to deal with them.”

Made of ink infused with the ceramic indium oxide, the 4cm monoliths are created by extruding the ink from a 3D printer and forming it into a lattice shape.

Because indium oxide bonds with PFAS, the chemicals attach to the monoliths and can be removed from the water in under three hours.

While testing has so far found that the monoliths remove 75 per cent of PFAS from water, the team is aiming to increase the efficiency of the process with further refinement.

The research was funded by the Engineering and Physical Sciences Research Council.

Source – The Engineer