Researchers clean up forever fouling with printer

Researchers at the University of Bath have invented a way to remove one of the most commonly-found of a group of harmful, near-indestructible chemicals from water – which they claim to be low-energy and rapid enough to be compatible with existing water treatment systems.

The researchers said their method removes “at least 75%” of perfluorooctanoic acid (PFOA) from water. The chemical is a breakdown product of substances used in stain-resistant fabrics and is one of a number of perfluoroalkyl substances (PFAS) known as “forever chemicals” owing to their resistance to degradation.

Researcher at the university’s Department of Chemical Engineering, Dr Liana Zoumpouli, said: “We have created an efficient way to remove these chemicals from water without using lots of energy.”

Their method uses 3D printing with ink that includes a ceramic, indium oxide, to form 4cm-long solid lattices each with a high surface area. The lattices – dubbed “monoliths” by the researchers – are then dropped into circulating PFOA-contaminated water and the PFOA binds to the indium oxide.

The monoliths were cleared of bound PFOA and regenerated by heating them to 500ºC to destroy the PFOA. 

Co-author of the researchers’ report, 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.”