September 2, 2009

Algae used to find contaminants in water

U.S. government scientists say they've refined their method of detecting contaminants in municipal water supplies by using algae as sentinels.

Oak Ridge National Laboratory researchers Elias Greenbaun and Miguel Rodriguez Jr. said their work demonstrates the technology has broader applications than previously reported. For example, they said, the sensitivity of the algae to toxins has a natural daily cycle that tracks the sun.

When the sun is overhead and shining brightly, the algae are less sensitive to the toxins, Greenbaum said. The new work shows that keeping the water sample in darkness for about 30 minutes prior to testing for toxins restores full sensitivity to the test.

He said the new results also show the technology can be applied to many different water quality environments, such as when the algae are starved for nutrients.

We have shown that microalgae in source drinking water can be used as broad-spectrum, robust sentinel sensors to detect relatively low concentrations of toxins, Greenbaum said. We have also shown that the microalgae do not need to be in an optimized state for this technology to be effective.

The scientists said discussions for commercialization of the technology, to be marketed under the name AquaSentinel, are under way.

The research is to appear in the journal Water Environment Research.