Water war against hormones

Ulster University researchers are using a harmless, cheap white pigment found in toothpaste in a revolutionary technique for removing the female sex hormone oestrogen from the water supply.

Oestrogen pollution, which comes from female contraceptive and HRT products, is a growing problem. Anglers increasingly report finding hermaphrodite fish. It is also known to cause sexual malfunctions in birds and mammals, including humans.

"Conventional sewage and water treatments do not remove oestrogen from the water supply," said Brian Eggins of UU's photocatalysis research team. "But we've discovered that if you shine an ultraviolet light on titanium dioxide, the titanium becomes activated, and capable of converting the oestrogen to CO2."

Titanium dioxide is a non-toxic pigment used in paints and creams. Because it is a catalyst it is not destroyed or used up by the ultraviolet treatment and is effective indefinitely. The treatment also removes the need to add chemicals to the water supply to purify it.

Researcher Heather Coleman is optimistic that the treatment will be effective against a number of other pollutants in the water supply that mimic the effects of oestrogen, such as agricultural pesticides and some detergents used in industrial cleaning processes.

These compounds and their residues are increasingly finding their way into the water supply, and are not completely removed by conventional water treatment methods. The UU team is assessing the effectiveness of the titanium treatment in destroying them. It is constructing a pilot treatment plant in collaboration with Lisburn-based engineering firm Texam, which is expected to start operating by the end of March.

The research is funded by the Northern Ireland Office's industrial research and technology unit and the environment and climate programme of the European Commission.