Using plants to clean polluted soils

PIKETON, Ohio – With gardens and fields of sweet corn, berries and other horticulture-related plots dotting the grounds of Ohio State University’s South Centers at Piketon, it would be easy to dismiss the dozen scraggly-looking potted plants sitting alone in one of the facility’s greenhouses.
With some plants thriving, others dead or dying, and other pots holding nothing but bare soil, it looks like a research project gone awry.
Their appearance, however, is the point of the research and, so far, is turning out to be what South Center’s soil scientist Rafiq Islam had hoped for.
The study. Islam is conducting a seed project to study phytoremediation – the use of plants to remove pollutants, specifically heavy metals, from the contaminated soil.
He is determining how well morning glory, red spinach and green spinach take up such heavy metals as aluminum, copper, chromium and cobalt.
Heavy metals are byproducts of industry, which are easily taken up by humans through inhalation, ingestion or absorption and can quickly become toxic, causing a variety of health problems ranging from organ failure to neurological impairment.
Survival? “The main idea of the study is to see what metals these three plants will take up, how much they will take up and if they survive the contamination,” Islam said.
“Hopefully they are tough enough to grow on industrial sites and aid in toxic cleanup. One use could be at the uranium plant here in Piketon.”
The Portsmouth Gaseous Diffusion Plant, located in Piketon, Ohio, was once part of a government program to produce uranium to fuel nuclear power plants.
The plant, now owned by the Department of Energy, has long ceased its operations and is in the stages of uranium production- associated trichloroethane decontamination via contracted cleanup efforts.
Industrial sites. Using phytoremediation on such industrial sites as an alternative to standard to chemical cleanup is nothing new and research on the uptake of heavy metals has involved a variety of plants.
Islam chose morning glory, red spinach and green spinach for the Ohio State project because they grow fast, grow almost anywhere in the world and produce a large amount of biomass.
“We want plants that will take up and accumulate the toxins in their stems and leaves, not their roots, and if we have plants with a large biomass it’s just easier for the plants to take up the heavy metals and easier to dispose of the plants after harvesting them.”
Analyzing. The plants in the study were subjected to 10 pounds, 20 pounds and 40 pounds of cobalt, aluminum and chromium, and 10 pounds, 20 pounds, 50 pounds and 100 pounds of copper.
The plants are being analyzed for survivability, rate of metal uptake, total metal uptake and where those metals are being stored in the plant.