University of Tulsa chemistry professor Tom Harris may elevate the status of a popular collegiate beverage - beer.
The scholar says the alcoholic suds may be a low-tech, low-cost solution to clean the orange-colored, iron-contaminated waters of Oklahoma's Tar Creek, one of the country's most urgent Superfund sites. An Oklahoma governor's Tar Creek Superfund Task Force has recommended engineering man-made wetlands to capture some of the zinc, lead and calcium that has been traveling from nearby mine chat piles into the creek. Harris claims that expired beer improves efficiency of the man-made wetlands to clean the water.
Harris, working alongside University of Tulsa biology professor William Rosche and several students, says the group has performed laboratory experiments that show that a wetland treated with beer would be far more effective in getting rid of heavy metals from runoff water than an untreated wetland. Key players in this clean-up system are sulfate-reducing bacteria - or SRB - that convert sulfate ions to sulfide ions, a process that separates the iron out of the water, trapping it in the soil. Another key microorganism is the fermenting bacteria, which consume the beer. "The goal is to get the mine drainage to pass through the organic matter and trap the heavy metals," Harris says. This process would leave cleaner water to wash downstream, he explains.
"Initially we were going to use molasses," Harris recounts. "However, we then learned that a beer distributor in Tulsa disposes of hundreds of gallons of waste beer each month, so we switched to beer." For now, Harris is using store-bought beer, but since the wetland must be recharged with beer periodically, he hopes beer distributors could be persuaded to donate their stale beer if he is able to construct a small-scale version of an engineered wetland in the Tar Creek area.