sealPurdue News

Purdue leads center using pollution-busting plants, microbes

WEST LAFAYETTE, Ind. – Purdue University will lead a new research center that uses natural systems, including plants and microorganisms, to control environmental contamination.

The federally funded center is one of five new Hazardous Substance Research Centers, and is supported by the Environmental Protection Agency, the Department of Energy, the Department of Defense, universities, industries, and state and other federal agencies.

Each center has a specific focus, concentrating on different issues and strategies to reduce and control hazardous substances in the environment. The Purdue-based center, with a consortium of eight universities, will focus on bioremediation, or using microbes to clean up pollution; phytoremediation, or using plants to get rid of contamination; and natural attenuation, or allowing the natural environment to cleanse itself over time.

"There has never been a center that has focused exclusively on these biological remediation technologies," said Kathy Banks, the center's director and a professor of civil engineering at Purdue. "Bioremediation and phytoremediation are gaining acceptance in the United States.

"Appropriate use of these technologies is being encouraged by the EPA, by industry and by community groups because they are noninvasive and low-cost."

The EPA Hazardous Substance Research Center Program began in 1989. Purdue will replace two former centers that had been led by Kansas State University and the University of Michigan.

"It was a fairly daunting task to go up against centers that had been operating for 10 years," Banks said, noting that her focus on phytoremediation helped Purdue successfully compete for the center. Banks will lead a diverse team of researchers with backgrounds ranging from biology and chemistry to engineering.

The center's associate directors are Lakshmi N. Reddi, a professor and head of Kansas State University's Department of Civil Engineering, and John T. Novak, a professor of civil and environmental engineering at Virginia Polytechnic Institute and State University.

"Much of the work we will be conducting at Virginia Tech is focused on monitored natural attenuation," Novak said. "The monitoring part is needed to ensure that the contaminants are going away, or at least not spreading.

"For example, suppose you have found a spill or discharge of petroleum or cleaning solvents in soil and it has spread to the groundwater, which is used by some nearby homes for drinking water. You can pump the source, or main blob of contamination, but material will remain attached to soil or outside the cleanup zone. We would then put wells into place to make sure the remaining contamination is not moving to the drinking water wells and in fact is being degraded by microbes in the soil."

Reddi said the center will play a crucial role in helping to clean up pollution from mining and other sources in industrial communities in Kansas and other locations in the Great Plains.

"By focusing on cost-effective, natural remediation, the Purdue center will provide a unique service to Kansas and other communities in the region," Reddi said.

The center is supported primarily by a five-year EPA grant, anticipated to total about $6 million. An additional $100,000 per year will come from industry and state agencies. Matching funds will be contributed by the universities in the consortium.

With about 30 percent of the funding dedicated to outreach, the center will work with state governments, local communities and industry to revitalize polluted sites, restoring their economic and social benefits, Banks said.

"The center will lead a large community outreach effort, and we expect that effort to grow over the years," Banks said. "We will support community organizations through environmental workshops, review of environmental cleanup plans and liaison activities between community groups and industry."

A critical element of the center's approach will be its focus on restoring so-called "brownfields," which are former or current industrial sites that are either polluted or are perceived by the public to be contaminated. Many of the properties have been abandoned, and their future is in limbo because of environmental contamination or a negative public perception. Indiana alone has many such sites, Banks said.

"Brownfields are a big issue in many states," she said.

Another important aspect of Purdue's new center is the industrial involvement.

"All of the center's research projects are co-sponsored by industry and many of them are field-based research," Banks said. "By partnering with industry, we are addressing real-world environmental problems with cost-effective solutions."

Working with Paul Schwab, a Purdue agronomy professor, Banks has pioneered the use of plants to rid petroleum products from soil.

The research team has used plants to help clean up a Texas oil pipeline spill, contamination at an Indiana site where manufactured gas was produced from coal, industrial sludge in California and diesel spills in Virginia and California. At the Indiana site, near Bedford, Banks and Schwab planted grasses and poplar trees on one part of the property to hasten the degradation of soil pollutants such as polycyclic aromatic hydrocarbons. The gunky, tar-like substance was left behind after decades of manufacturing natural gas from coal.

"The roots of the poplars grow down into the sludge zone," Banks said.

Poplars are in a category of plants called phreatophytes, which send their roots deep into the soil in search of water. The "water-loving" plants help to keep polluted water from moving to nearby streams and rivers.

"But also there are microorganisms that exist around the roots of plants that can actually degrade the contaminants," Banks said.

A variety of other plants can be used for specific environmental woes. For example, plants that accumulate metals can be grown on lands contaminated with heavy metals, such as lead. The plants are then harvested to remove the contamination. Vegetation such as grasses and clovers are promising for certain projects because their root systems stimulate the growth of microbes that help to break down organic pollutants.

The center's 10-state outreach region consists of Indiana, Ohio, Illinois, Michigan, Minnesota, Wisconsin, Kansas, Missouri, Nebraska and Iowa. The other universities in the consortium are Virginia Polytechnic Institute and State University, the University of Cincinnati, Michigan State University, the University of Missouri at Rolla, Howard University, Kansas State University, Central State University and Haskell Indian Nations University. The four other new centers are headquartered at The Johns Hopkins University, Louisiana State University, Colorado State University and Oregon State University.

Writer: Emil Venere, (765) 494-4709,

Sources: Kathy Banks, (765) 496-3424,

John T. Novak, (540) 231-6132,

Lakshmi N. Reddi, (785) 532-1586,

Purdue News Service: (765) 494-2096;

* To the Purdue News and Photos Page