Featured Research

from universities, journals, and other organizations

Researchers Study Role Of Natural Organic Matter In Environment

Date:
December 20, 2006
Source:
University of Illinois at Urbana-Champaign
Summary:
The decomposition of plant, animal and microbial material in soil and water produces a variety of complex organic molecules, collectively called natural organic matter. These compounds play many important roles in the environment.

The decomposition of plant, animal and microbial material in soil and water produces a variety of complex organic molecules, collectively called natural organic matter. These compounds play many important roles in the environment.

By studying the molecular mechanisms responsible for the complex behavior of natural organic matter, researchers at the University of Illinois at Urbana-Champaign are finding new ways to prevent the compounds from fouling water purification and desalination facilities.

Natural organic matter is ubiquitous in soils, waters and sediments. In agriculture, natural organic matter is important because of its positive effects on the structure, water retention and nutrient properties of soils.

Natural organic matter also interacts with metal ions and minerals to form complexes of widely differing chemical and biological nature. Solubility, mobility and toxicity of many trace metals are strongly correlated with the concentration of natural organic matter in soil and water.

Natural organic matter creates problems for the water supply industry, however, requiring removal to minimize water color and giving rise to potentially harmful chemical byproducts as a result of chlorination. Through a process called "bio-fouling," natural organic matter is also a major culprit in degrading the performance of membrane filtration systems used for water purification and desalination.

However persistent and universal natural organic matter molecules are in the environment, they are little understood. Natural organic matter has no unique structure or composition, cannot be crystallized and is extremely difficult to characterize.

Illinois researcher Andrey Kalinichev and geology professor James Kirkpatrick have used computer simulations and nuclear magnetic resonance spectroscopy to investigate some of the factors that contribute to the complex behavior of dissolved natural organic matter. They will present their findings at the American Geophysical Union meeting in San Francisco, Dec. 11-15. A paper reporting their findings has been accepted for publication in the European Journal of Soil Science.

"Bio-fouling is one of the most important problems in developing advanced membrane technologies for water purification and desalination," Kalinichev said. "It creates great complications for the industry."

Because of its acidic nature, natural organic matter can form complexes with dissolved metal ions. The binding of ions such as calcium, sodium, magnesium and cesium to natural organic matter, and their potential effects on bio-fouling were studied using molecular dynamic computer simulations performed by Kalinichev, and nuclear magnetic resonance measurements performed by Kirkpatrick and former student Xiang Xu.

"Membrane researchers know that when calcium is present, bio-fouling occurs very fast and filters clog quickly," Kalinichev said. "But when only magnesium or sodium is present, the filters clog more slowly, if at all."

Using relatively simple but realistic molecular models of natural organic matter dissolved in ionic solutions, Kalinichev and Kirkpatrick found that sodium and magnesium ions have very weak interactions with natural organic matter. Cesium interacts more strongly, but calcium has the strongest interaction with natural organic matter.

The strength of the interactions of ions with natural organic matter is dependent upon multiple factors such as ion size, electric charge, and the energy it takes to break the hydration shell of water molecules around the ions, Kalinichev said.

Metal ions in water are usually hydrated, which means they are surrounded by water molecules. For these ions to form strong complexes with natural organic matter, the attached water molecules must be removed.

When this happens, several negatively charged molecules of natural organic matter can simultaneously attach to the same ion, creating much larger aggregates. These aggregates are responsible for the formation of bio-fouling layers on membrane surfaces.

In addition to clogging filters, natural organic matter can change the mobility of certain toxic metals in soil and water.

"We performed our experiments and computer simulations with ions such as sodium and calcium because their behavior in water is already well studied," Kalinichev said. "Our next step is to use these models to study the effects of natural organic matter interaction with less common but more toxic metals such as strontium, lead, mercury, zinc and nickel."

This work was funded by the U.S. Department of Energy and the National Science Foundation.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "Researchers Study Role Of Natural Organic Matter In Environment." ScienceDaily. ScienceDaily, 20 December 2006. <www.sciencedaily.com/releases/2006/12/061211221222.htm>.
University of Illinois at Urbana-Champaign. (2006, December 20). Researchers Study Role Of Natural Organic Matter In Environment. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2006/12/061211221222.htm
University of Illinois at Urbana-Champaign. "Researchers Study Role Of Natural Organic Matter In Environment." ScienceDaily. www.sciencedaily.com/releases/2006/12/061211221222.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
Argentina Worries Over Decline of Soybean Prices

Argentina Worries Over Decline of Soybean Prices

AFP (Sep. 27, 2014) The drop in price of soy on the international market is a cause for concern in Argentina, as soybean exports are a major source of income for Latin America's third largest economy. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Mama Bear, Cubs Hang out in California Backyard

Mama Bear, Cubs Hang out in California Backyard

Reuters - US Online Video (Sep. 27, 2014) A mama bear and her two cubs climb trees, wrestle and take naps in the backyard of a Monrovia, California home. Vanessa Johnston reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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