Thursday, February 03, 2000
UC professor's process cleans chemical from water
BY BEN L. KAUFMAN
The Cincinnati Enquirer
In the pricey world of research, Professor Makram T. Suidan's federally funded experiment is a project officer's dream.
For a modest amount, this University of Cincinnati environmental engineer has found an answer to MTBE, the latest, high-profile threat to the nation's drinking water.
A success in his lab, the process is ready to be field-tested and assessed for commercial feasibility.
MTBE (methyl teritary butyl ether) is added to gasoline by some refiners to reduce tailpipe emissions where smog is a major problem. That refor mulated gasoline was the Environmental Protection Agency's way of introducing cleaner-burning fuel in the mid-1990s. However, damaged storage tanks allow the fuel gasoline to leak into ground water where MTBE dissolves easily and flows into wells on which myriad communities and families rely.
“It tastes bad, it smells bad,” said Dr. Albert Venosa, who is Dr. Suidan's EPA proj ect officer.
MTBE also is a suspected human carcinogen, Dr. Suidan said. “You really want it out.”
His process applies existing chemistry and plumbing and uses bacteria to turn MTBE into carbon dioxide and water.
EPA's cost to date: about $250,000.
“I'm as excited about it as he is,” Dr. Venosa said. “When I saw the data, I couldn't believe it.”
Dr. Venosa, an environmental microbiologist at EPA's national research center near UC, has become a believer.
Dr. Suidan began his experiment in 1998 amid widespread doubt about the ability of bacteria to attack MTBE as effectively as other pollutants.
The conventional aeration tank added bacteria and oxygen to contaminated water. After bacteria did their work, clean water flowed out over the lip of the tank. At the same time, many of the bacteria settled to the bottom of the tank for reuse.
However, too many beneficial bacteria floated out with treated water. “That's not good,” Dr. Suidan said. “You're losing the workers.”
His breakthrough came when Dr. Suidan adopted a commercially available 12-liter “porous pot” that retained all of the bacteria while treated water flowed out.
That meant his pot — made of a polymeric membrane — could treat MTBE-contaminated water continuously.
“We were all skeptical,” Dr. Venosa recalled. “The molecule was very difficult for the bacteria to act upon.”
Before long, however, Dr. Suidan's porous pot was breaking MTBE “down to the limits of detection” or 1 part per billion (ppb), Dr. Venosa recalled. “Much to our disbelief, he was getting very good biodegradation.”
More money followed from the MTBE treatment program at EPA's national risk management research laboratory. “Dr. Suidan does very good work, is a very careful worker,” Dr. Venosa said.
His “membrane bio-reactor” worked again in a 60-liter vat with a porous ceramic membrane that cleaned up to 500 liters a day.
Dr. Suidan said he regularly reduces MTBE to below 5 ppb in water samples contaminated with 150,000 ppb.
MTBE affects taste and odor down to 4 ppb, according to the Kentucky Department of Environmental Protection, although the EPA's 1997 drinking water advisory said 20 to 40 ppb should be acceptable.
Either way, those concentrations were far below those blamed for cancer in mice and suspected in human cancers, but the national debate over the risks and benefits of continued MTBE use in gasoline is unresolved.
Before long, the agency will seek proposals to field test various processes for cleansing MTBE from ground water. That's beyond his means, so Dr. Suidan said he hopes to work with a successful applicant.
Commercial potential is suggested by the way Dr. Suidan's device treats MTBE at any concentration or flow-rate, Dr. Venosa said.
EPA still is studying whether there are human health effects from MTBE-contaminated water.
Dr. Suidan is working with another way to break down MTBE that shows “great promise” for contaminated ground water without pumping it to the surface.
This process injects hydrogen peroxide into ground water where — with natural iron as a catalyst — it also breaks down MTBE into carbon dioxide and water.
Whether either or neither of his processes will be adopted for commercial use is an open question, Dr. Suidan said. “The question ultimately will be which is cheaper and which is more effective.”
Schools get tough on bomb threats
Public defenders' pay near lowest
Bush win is no sure thing in Ohio
Taft: Bush's Ohio campaign energized by challenge
Gore asks students for help
Lawsuit just an invitation to go shopping
County to pitch in on pilings
Family sues in home invasion, dog shooting
Lebanon can ask retirement refund
Liquor sales likely for Ky. Speedway
Possible vote fraud examined
Street grid for new riverfront readied
Take a kid to work day
UC professor's process cleans chemical from water
Clerks must ask if you're marryin' kin
Ludlow blaze destroys houses
State aid sought for Riverfront West
Patton pushing tax plan up steep hill
BenGal takes pompoms to Pro Bowl
Sweeps offer a few sweets
GET TO IT
Getting married? Be in our 'Love Story'
Queen City's moments to shine reflected in book
Area's ready for tornado season
Booby-trap case heads for trial
Churches win right of refusal in House
City report finds no systematic bias
Coalition discusses historic preservation
House passes cap on makers' liability
Jury gets brothers' case
Man, girl arrested after police chase
Man safe from fire, but not fall
Monroe looking at school bond
Norwood intimidation case dismissed
Norwood, police reach tentative deal
Policeman fired, dog out of job
Road name carries memory
TRISTATE DIGEST
TV veteran channels energy into serving city
