Nature’s Kidneys

Wright State environmental scientist Abinash Agrawal, Ph.D., (right) and Michael Shelley, Ph.D., of the Air Force Institute of Technology at their wetland site at Wright-Patterson Air Force Base. The white tubes in the background represent some of the 200 monitoring wells where the researchers are studying how microbes can remove toxic compounds from groundwater and the soil.

Scientists at Wright State University and the Air Force Institute of Technology (AFIT) are conducting an experimental project at Wright-Patterson Air Force Base (WPAFB) to demonstrate how wetlands can help clean up the environment by removing toxic compounds from the groundwater and soil.

“Our findings show that microbes are destroying very toxic chlorinated, organic compounds in our research site,” said Abinash Agrawal, Ph.D., an associate professor in Wright State’s Department of Earth and Environmental Sciences and principal researcher of the wetland project. “Many wetlands have been established by scientists throughout America to control sediments and nutrients, but ours is the only wetland that I am aware of that has been established to investigate destruction of toxic organic compounds.”

Agrawal said the goal of this project has significant economic implications. “Chlorinated organic compounds are widespread groundwater contaminants that cause most of the groundwater pollution in this country,” he explained. “This contamination affects drinking water quality at hundreds of thousands of sites in the United States. Since the cost of cleaning up these sites by existing techniques range in tens of billions of dollars, a passive treatment approach by natural processes using the wetland is a cost-effective approach for groundwater remediation and site cleanup.”

Agrawal works closely with Michael Shelley, Ph.D., a professor of environmental science and engineering at AFIT, and with James Amon, Ph.D., a Wright State professor emeritus of biological science, in this cooperative venture between Wright State and AFIT.

“In humans, our kidneys function to filter out the toxins from our body, and we are finding the wetland to be nature’s kidneys that filter out toxic pollutants present in the water passing through it,” explained Agrawal, a biogeochemist with more than 15 years of experience in studying the environment, particularly wetlands, water quality, and groundwater contamination.

According to Shelley, “The wetlands are really nature’s way of cleaning up many contaminants.”

This experimental wetland research site is a small 70-by-100-foot parcel in Area C at the Air Force base. The project started in 1999 with conversion of the vacant land into a wetland marsh, dominated by standing water and brush and sponsored and funded by several government agencies.

The contaminated water in the experimental wetland flows upwards to optimize the treatment process. Some 200 monitoring points have been established within the wetland, and a team of scientists from diverse disciplines is investigating the process of pollutant destruction in the shallow soil and groundwater.

“We are looking at the interactions between microbes and soil and water from a chemical and biological perspective,” Agrawal said. “Microbes are present everywhere in our soil and water, but they are more active in a wetland environment, probably because of the greater availability of food and moisture content these swampy areas possess.”

Agrawal said seed funding for the laboratory work prior to building the wetland research site was provided by the Dayton Area Graduate Studies Institute. Further funding for field research is provided by AFIT annually. The funding for this project started out in the range of $40,000 annually but now involves annual allocations in the $200,000 range, in addition to analytical instruments and support for post-doctoral fellowships.

“Over the years, the grant total the project has received is between $2 and $3 million,” said Shelley, who explained that over time the project would save millions of dollars for the Air Force and billions of dollars for industry across the country.