In the plants Schott and Scardina have investigated, air bubble eruptions have carried solid particles into the filtration process, which leaves the treatment systems open to pathogen contamination. Schott is concerned about the potential for outbreaks of viruses, as well as Giardia and Cryptosporidium, both of which are microscopic parasites that can cause severe gastro-intestinal illness. These parasites are impervious to chlorine disinfection, so they must be removed through settling or filtration. A major water-borne outbreak of Cryptosporidium in Milwaukee in 1993 caused illness in an estimated 403,000 people.

These and other water-borne diseases are a threat whenever a treatment plant is compromised, which makes Scardinas research a potentially important human health tool.

In August, the AWWARF awarded a $150,000 grant to Scardina for continuation of his air bubble research. "Whats most impressive to me is that a conservative professional organization has been persuaded to fund a students original research," Edwards says. "Its unusual for a Ph.D. student to lead an effort that wins a competitive grant through AWWARFs unsolicited proposal process."

Scardina will use the grant to "get a handle on the magnitude of the problem," he says. Working with treatment plant engineers, he is investigating air bubbles in Boulder and Denver, Colorado; Bay City, Michigan; San Diego, California; Myrtle Beach, South Carolina; and Buffalo Pound in Canada. "Im studying parameterssuch as treatment plant design and operationsthat can affect formation of bubbles."

After he completes his Ph.D. in another year or so, Scardina wants to work in the water treatment industry and continue h
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Contact: Dr. Marc Edwards
edwardsm@vt.edu
540-231-7236
Virginia Tech
5-Oct-2001