WESTVILLE - Sometimes good intentions have bad results. Case in point: The gasoline additive methyl t-butyl ether (MTBE), is one of the oxygenates frequently added to gasoline in an attempt to improve air quality. That has happened, but now MTBE has become a dangerous threat to the groundwater supplies. In some parts of the country, notably on the West Coast, whole communities have had their water supplies rendered unusable by gasoline containing MTBE which has leaked from underground storage tanks. Now, a Purdue University North Central researcher thinks he is on track to a solution to that problem.

In a paper* presented this week (March 26-31) to the 219^th National Meeting of the American Chemical Society, Dr. Reynaldo Barreto, assistant professor of chemistry, said he is able to destroy MTBE as well as two other hazardous additives, ETBE (ethyl t-butyl ether) and TAME (t-amyl methyl ether) using a photocatalytic process utilizing ultraviolet light and titanium dioxide (TiO₂).

"In the lab, we can destroy 95 percent of the MTBE and ETBE in gasoline in as little as four hours," Barreto said. "Our current work shows that 75 percent of TAME is also destroyed. The total organic chemical content also goes down."

Destroying these compounds in the lab is one thing, but doing it once the pollutants have reached the groundwater is something else. That, Barreto says, is the next stage of his research. He has some ideas for a commercially viable method and will begin testing it within the next few months.

The recently announced intent by the Clinton administration to ban MTBE within the next three years will not make the problem go away, Barreto said. For one thing, MTBE is already in the groundwater in many places, particularly on the West Coast and massive cleanup efforts will be needed. Second, getting the Clean Air Act amended quickly by Congress could be problematic, particularly in this election year. "As long as the Clean Air Act is not amended, they'll have to add something else," he said. "And it could be even worse."

Barreto has been studying gasoline additives since 1991, when he was a postdoctoral research fellow at the University of Notre Dame. "The government mandated that the oil companies put in additives to oxygenate their gasoline," he said. "The problem is that no one knew what other effects it might have.

"My research has been two-fold: how compounds such as MTBE, ETBE and TAME get into the water and then how to get them out."

Barreto has been assisted in his research by Phillip Barr, a former student, and Chris Chavis, a senior biology major at Purdue North Central.

* ENVR 1 17 (374393) T Photocatalytic destruction of Ethyl t-butyl ether (ETBE) and t-amyl methyl ether (TAME)"

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