Decontamination development

Researchers at Sandia National Laboratories claim to have created a material that is far more effective at decontaminating water than any other product on the market.

Sandia has applied for a patent on the material, which removes bacterial, viral and other organic and inorganic contaminants from river water destined for human consumption, and from wastewater treatment plants prior to returning water to the environment.

Sandia is working with a major producer of water-treatment chemicals to explore the commercial potential of the compound.

The water-treatment reagent, known as a coagulant, has been made by substituting an atom of gallium for an aluminium atom in the centre of an aluminium oxide cluster – itself a commonly used coagulant in water purification.

The substitution uses a simple chemical process of dissolving aluminium salts in water, gallium salts into a sodium hydroxide solution and then slowly adding the sodium hydroxide solution to the aluminium solution while heating.

May Nyman, principal investigator at Sandia, said: 'The substitution of a single gallium atom in that compound makes a big difference. It greatly improves the stability and effectiveness of the reagent. We've done side-by-side tests with a variety of commercially available products. For almost every case, ours performs best under a wide range of conditions.'

The Sandia coagulant attracts and binds contaminants so well because it maintains its electrostatic charge more reliably than conventional coagulants made without gallium, itself a harmless addition.

The project was conceived and all water-treatment studies were performed at Sandia, said Nyman, who worked with Sandia microbiologist Tom Stewart on the project.