Purer Water: A Single Atom Makes A Big Difference
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By Grace V. Jean and Sandra I. Erwin
By substituting a single atom in a molecule widely used to purify water, researchers at Sandia National Laboratories have created a decontaminant that researchers believe has a greater shelf life than other products currently 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.
“Human consumption of ‘challenged’ water is increasing worldwide as preferred supplies become more scarce,” said Sandia principal investigator May Nyman.
The study was published in June 2009 in the journal Environmental Science & Technology, a publication of the American Chemical Society. Sandia is working with a producer of water treatment chemicals to explore the commercial potential of the compound.
The water-treatment reagent, known as a coagulant, is made by substituting an atom of gallium in the center of an aluminum oxide cluster — itself a commonly used coagulant in water purification, says Nyman.
The substitution uses a simple chemical process of dissolving aluminum salts in water, gallium salts into a sodium hydroxide solution and then slowly adding the sodium hydroxide solution to the aluminum solution while heating.
“The substitution of a single gallium atom in that compound makes a big difference,” said Nyman. “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.”