Common Weed Reduces Salt Content In Contaminated Soils, Study Suggests

November 25, 1997

ATHENS, Ohio -- A new study at Ohio University suggests that a weed found around the United States can reduce the salt content in soil contaminated by brine spills, a common environmental problem on sites being drilled for oil or gas.

Brine -- water saturated with three to 10 times more salt than seawater -- is toxic to plants. Without human intervention, it can take years for the saline content in the soil at a spill site to return to levels that allow plant growth.

But researchers found that knotweed, a member of the Buckwheat family, grows well in high-saline soil, and actually helps to remove the salt so that other plants can once again thrive.

"When companies drill for oil, they also get brine, and the brine is usually stored in a tank on the site," said Irwin Ungar, professor of environmental and plant biology at Ohio University and co-author of the study. "At the site we studied, the brine spill occurred in 1989 when workers were pumping the salt water out for storage."

The following year, researchers began studying the site, about 15 miles northeast of Athens, and noticed that while all vegetation on the site was dead, knotweed was growing on the periphery. Four years later, when the saline content was still 1 to 2 percent above normal, the knotweed was thriving inside the spill area.

Soil tests proved that the plant had helped to reduce the saline content of the soil. Researchers believe that the site will be returned to its pre-spill state with the aid of the plant's natural saline-removing ability and rainfall that helps to dilute the salt content. The knotweed studied, Polygonum aviculare L, is a ground-covering leafy plant speckled with small pink flowers. It's related to Japanese knotweed, a much more aggressive weed that creates problems for gardeners around the country.

Although knotweed is not as saline-tolerant as plants found in salt marshes and other coastal areas, its wide habitat range would make it an ideal candidate for efforts to restore contaminated soil naturally and inexpensively, Ungar said.

"Currently, soil contaminated by brine must be removed and landfilled," he said. "Using this or some other saline-tolerant plant to remove salt from the soil through natural means would be more environmentally and economically desirable."

The research was co-authored by Margaret Foderaro, a former Ohio University graduate student in environmental and plant biology. It was supported by the Petroleum Environmental Research Forum and appeared in a recent issue of the journal American Midland Naturalist.

- 30 -





Contact: Irwin Ungar, 614-593-1120; iungar1@ohiou.edu.
Written by Kelli Whitlock, 614-593-0383; kwhitlock1@ohiou.edu.

Ohio University

Related Salt Articles from Brightsurf:

A salt solution toward better bioelectronics
A water-stable dopant enhances and stabilizes the performance of electron-transporting organic electrochemical transistors.

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.

New technology helps reduce salt, keep flavor
A new processing technology out of Washington State University called microwave assisted thermal sterilization (MATS) could make it possible to reduce sodium while maintaining safety and tastiness.

The salt of the comet
Under the leadership of astrophysicist Kathrin Altwegg, Bernese researchers have found an explanation for why very little nitrogen could previously be accounted for in the nebulous covering of comets: the building block for life predominantly occurs in the form of ammonium salts, the occurrence of which could not previously be measured.

Salt helps proteins move on down the road
Rice chemists match models and experiments to see how salt modifies surface interactions in chromatography used to separate valuable drug proteins.

Mars once had salt lakes similar to Earth
Mars once had salt lakes that are similar to those on Earth and has gone through wet and dry periods, according to an international team of scientists that includes a Texas A&M University College of Geosciences researcher.

Marathoners, take your marks...and fluid and salt!
Legend states that after the Greek army defeated the invading Persian forces near the city of Marathon in 490 B.C.E., the courier Pheidippides ran to Athens to report the victory and then immediately dropped dead.

Water solutions without a grain of salt
Monash University researchers have developed technology that can deliver clean water to thousands of communities worldwide.

Solving the salt problem for seismic imaging
Automated imaging of underground salt bodies from seismic data could help streamline oil and gas exploration.

Higher salt intake can cause gastrointestinal bloating
A study led by researchers at the Johns Hopkins Bloomberg School of Public Health found that individuals reported more gastrointestinal bloating when they ate a diet high in salt.

Read More: Salt News and Salt Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.