Poplar Trees Hold Promise For Removing Contaminants

In an award-winning paper on the subject of "phytoremediation," Dr. Joel G. Burken, an assistant professor of civil engineering at UMR, says poplar trees can remove contaminants such as atrazine from soil. Atrazine is the most heavily used agricultural herbicide in the United States, Burken says.

"Atrazine is not a problematic chemical when used properly, but in many locations it contaminates soil and water due to overuse or improper disposal techniques," Burken says.

In a paper published in the Journal of Environmental Engineering, Burken and his co-author, Dr. Jerald Schnoor of the University of Iowa, report that laboratory tests show that hybrid poplars can aid in the breakdown of atrazine in the soil. From there, the poplars can absorb atrazine found in groundwater.

Once taken into the tree's tissues, Burken says, the atrazine breaks down over time "to form less toxic and less problematic daughter products," such as hydroxyatrazine. Planting poplar trees on a site contaminated by atrazine, then, could be one method of removing the contaminant from the soil.

Phytoremediation may be a more efficient technique for cleaning up the environment than more traditional techniques, such as incineration or landfill disposal, Burken says. "Using phytoremediation simultaneously restores soil health and revegetates during the cleansing of the site, unlike some technologies that basically leave the soil barren of any soil organisms or plant life," he says. In addition, phytoremediation is economical, environmentally friendly, and more acceptable to the public than some other techniques.

"The public acceptance of phytoremediation is generally not a problem as it can be with other, less aesthetically pleasing technologies," Burken says. "The primary hurdle that remains is answering when, where and how phytoremediation can be effectively applied. I hope my research can provide some needed answers."

In July, Burken and Schnoor received the 1998 Rudolph Hering Medal from the American Society of Civil Engineers' Environmental Engineering Division for their research paper, "Phytoremediation: Plant Uptake of Atrazine and Role of Root Exudates." The paper was first published in the November 1996 issue of the Journal of Environmental Engineering.

Burken's rural background helped form his interest in this research. "Having grown up on a farm in Iowa," he says, "I find this research extremely interesting, with its ties to agricultural practices and chemicals."