Safe Enough to Drink?
from USF Magazine, Fall/Winter 2004, vol 46 no 2
A USF researcher and her colleagues are looking for new ways to sustain the nation’s water supplies. And that may mean one day reclaiming water for drinking purposes.
“The luxury of using water once is no longer an option,” says Audrey Levine, a USF associate professor of civil and environmental engineering. Her comments, published in the June issue of Environmental Sciences and Technology, came on the heels of the U.S. Geological Survey’s recent announcement that the western states of the U.S. are experiencing the worst drought in 500 years.
According to Levine, new water treatment technologies and monitoring tools have made the prospect of recycling water, even for drinking purposes, much more feasible.
Reclaiming water for industrial and irrigation purposes is nothing new. But, reclaiming water for drinking purposes is. Among her current research projects, Levine is investigating a process by which reclaimed water used for cooling thermoelectric power plants can be re-purified by capitalizing on waste energy available to allow for distillation—in other words, recycling the waste water twice.
“The use of highly treated reclaimed water to augment drinking supplies is possible,” says Levine. She adds that treatment technologies—like bioreactors, microfiltration, ultrafiltration, nanofiltration and reverse osmosis—combined with molecular biology techniques, have improved significantly over the last ten years, making it possible to ensure minimal risk from the use of reclaimed water.
Considering that the World Bank has projected that over the next century available water must increase by up to 60 percent to meet global needs, Levine’s work, and that of her colleagues, holds great import. “For water supplies to be sustainable, the rate at which water is withdrawn from sources needs to be in balance with the rate of renewal or replenishment. At the same time, water quality must be recoverable.”
To that end, Levine acknowledges there are a number of challenges.
“Over the last 50 years, the nature of wastewater has changed because of increased chemical, medical and household residual by-products introduced into the waste stream,” explains Levine. “Consequently, the water reclamation community is constantly fighting new battles to address contaminants and pathogens.”
The current challenge, she says, is to develop and implement sound scientific, reliable, practical and efficient monitoring tools coupled with effective treatment systems to ensure minimal risk from inadvertent exposure to reclaimed water.
They are challenges Levine and her colleagues are eagerly taking on.
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