Featured Research

from universities, journals, and other organizations

Ultrasound And Algae Team Up To Clean Mercury From Sediments

Date:
March 29, 2006
Source:
Ohio State University
Summary:
Ultrasound and algae can be used together as tools to clean mercury from contaminated sediment, according to an Ohio State University study. This research could one day lead to a ship-borne device that cleans toxic metals from waterways without harming fish or other wildlife.

This scanning electron microscope image shows particles of cinnabar before sonication. Ohio State University scientists are developing a technique to clean mercury from contaminated sediment. In this technique, ultrasonic waves vibrate sediment particles so that the mercury is released into the water, then algae absorbs the mercury form the water. Here, cinnabar (mercury sulfide) is used in the laboratory to demonstrate the process.
Credit: Image courtesy of Ziqi He, Ohio State University

Ultrasound and algae can be used together as tools to clean mercury from contaminated sediment, according to an Ohio State University study.

This research could one day lead to a ship-borne device that cleans toxic metals from waterways without harming fish or other wildlife, said Linda K. Weavers, the John C. Geupel Chair in Civil Engineering at Ohio State.

Doctoral student Ziqi He described the group's latest results in a poster session March 27 at the American Chemical Society meeting in Atlanta.

Weavers' research group previously determined that ultrasonic vibrations can shake mercury loose from sediment.

"We found ultrasound to be very effective at getting mercury out of sediment and into water," He explained. "But then we needed a third party to get the mercury out of the water. That's how we got the idea to add a biological element to the treatment."

Weavers and He joined with Richard Sayre, professor of plant, cellular and molecular biology at Ohio State, and Surasak Siripornadulsil, a former graduate student in the university's biophysics program. Sayre's team has genetically modified a species of algae to boost its natural ability to absorb heavy metals.

In laboratory tests, student He vibrated an ultrasonic probe inside beakers containing water, sediment, and algae. The vibrations freed mercury from the sediment, and within seconds, the algae adsorbed up to 60 percent of the mercury from the water. The combined system of ultrasound and algae removed 30 percent of the mercury from sediment within the first few minutes.

There are alternative cleanup methods that also absorb a high percentage of metals, Sayre admitted, but they are less selective -- they absorb all metals. His modified algae species absorbs five times the normal amount of a select group of toxic metals, including mercury, cadmium, copper, and zinc.

"Say you were trying to clean water that contained effluent with a lot of calcium or iron in it -- or seawater, which contains sodium," Sayre said. "If your algae aren't selective, they'll absorb those other metals and you'll recover less mercury. So the advantage of these modified algae is that other metals don't interfere with the cleanup."

Weavers envisions that boats could dredge sediments from contaminated waterways and clean them on board using ultrasonic equipment and algae-based filters. Then the clean sediment could be returned to its original location. Or, the equipment could be placed directly on sediment to treat it in place. Either procedure would leave wildlife unharmed, she said.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Ultrasound And Algae Team Up To Clean Mercury From Sediments." ScienceDaily. ScienceDaily, 29 March 2006. <www.sciencedaily.com/releases/2006/03/060329085054.htm>.
Ohio State University. (2006, March 29). Ultrasound And Algae Team Up To Clean Mercury From Sediments. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2006/03/060329085054.htm
Ohio State University. "Ultrasound And Algae Team Up To Clean Mercury From Sediments." ScienceDaily. www.sciencedaily.com/releases/2006/03/060329085054.htm (accessed August 20, 2014).

Share This




More Earth & Climate News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Wildfire Hits California's Angeles National Forest

Wildfire Hits California's Angeles National Forest

Reuters - US Online Video (Aug. 17, 2014) A wildfire sweeps across the Angeles National Forest prompting campers to quickly leave as officials began evacuating the area -- local media. Gavino Garay reports. Video provided by Reuters
Powered by NewsLook.com
Symphony Performs at Southern Utah's Red Rocks

Symphony Performs at Southern Utah's Red Rocks

AP (Aug. 16, 2014) The Utah Symphony hopes to complement the beauty of Utah's soaring red rocks and canyons with free desert performances near Utah's national parks this weekend. (Aug. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins