Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Treated carbon pulls radioactive elements from water

20.01.2017

Researchers at Rice, Kazan universities develop unique sorbents, target Fukushima accident site

Researchers at Rice University and Kazan Federal University in Russia have found a way to extract radioactivity from water and said their discovery could help purify the hundreds of millions of gallons of contaminated water stored after the Fukushima nuclear plant accident.


C-seal F, a carbon source, magnified 200 times reveals its high surface area of 12.5 square meters per grams. Processing it into oxidatively modified carbon raises its surface area to 16.9 square meters per gram while enhancing its ability to remove radioactive cesium and strontium from water, according to researchers at Rice University and Kazan Federal University.

Credit: Kazan Federal University


C-seal F, a source used to synthesize oxidatively modified carbon, is seen magnified 20 times by a scanning electron microscope. The material is highly effective at removing radionuclides from water, according to researchers at Rice University and Kazan Federal University.

Credit: Kazan Federal University

They reported that their oxidatively modified carbon (OMC) material is inexpensive and highly efficient at absorbing radioactive metal cations, including cesium and strontium, toxic elements released into the environment when the Fukushima plant melted down after an earthquake and tsunami in March 2011.

OMC can easily trap common radioactive elements found in water floods from oil extraction, such as uranium, thorium and radium, said Rice chemist James Tour, who led the project with Ayrat Dimiev, a former postdoctoral researcher in his lab and now a research professor at Kazan Federal University.

The material makes good use of the porous nature of two specific sources of carbon, Tour said. One is an inexpensive, coke-derived powder known as C-seal F, used by the oil industry as an additive to drilling fluids. The other is a naturally occurring, carbon-heavy mineral called shungite found mainly in Russia.

The results appear this month in Carbon.

Tour and researchers at Lomonosov Moscow State University had already demonstrated a method to remove radionuclides from water using graphene oxide as a sorbent, as reported in Solvent Extraction and Ion Exchange late last year, but the new research suggests OMC is easier and far less expensive to process.

Treating the carbon particles with oxidizing chemicals increased their surface areas and "decorated" them with the oxygen molecules needed to adsorb the toxic metals. The particles were between 10 and 80 microns wide.

While graphene oxide excelled at removing strontium, Tour said, the two types of OMC were better at extracting cesium, which he said has been the hardest element to remove from water stored at Fukushima. The OMC was also much easier and less expensive to synthesize and to use in a standard filtration system, he said.

"We know we can use graphene oxide to trap the light radioactive elements of relevance to the Fukushima cleanup, namely cesium and strontium," Tour said. "But in the second study, we learned we can move from graphene oxide, which remains more expensive and harder to make, to really cheap oxidized coke and related carbons to trap these elements."

While other materials used for remediation of radioactive waste need to be stored with the waste they capture, carbon presents a distinct advantage, he said. "Carbon that has captured the elements can be burned in a nuclear incinerator, leaving only a very small amount of radioactive ash that's much easier to store," Tour said.

"Just passing contaminated water through OMC filters will extract the radioactive elements and permit safe discharge to the ocean," he said. "This could be a major advance for the cleanup effort at Fukushima."

The two flavors of OMC particles - one from coke-derived carbon and the other from shungite -- look like balls of crumpled paper, or roses with highly irregular petals. The researchers tested them by mixing the sorbents with contaminated water as well as through column filtration, a standard process in which fluid is pumped or pulled by gravity through a filter to remove contaminants.

In the mixing test, the labs dispersed nonradioactive isotopes of strontium and cesium in spring water, added OMC and stirred for two hours. After filtering out the sorbent, they measured the particles left in the water.

OMC1 (from coke) proved best at removing both cesium and strontium from contaminated water, getting significantly better as the sorbent was increased. A maximum 800 milligrams of OMC1 removed about 83 percent of cesium and 68 percent of strontium from 100 milliliters of water, they reported.

OMC2 (from shungite) in the same concentrations adsorbed 70 percent of cesium and 47 percent of strontium.

The researchers were surprised to see that plain shungite particles extracted almost as much cesium as its oxidized counterpart. "Interestingly, plain shungite was used by local people for water purification from ancient times," Dimiev said. "But we have increased its efficiency many times, as well as revealed the factors behind its effectiveness."

In column filtration tests, which involved flowing 1,400 milliliters of contaminated water through an OMC filter in 100-milliliter amounts, the filter removed nearly 93 percent of cesium and 92 percent of strontium in a single pass. The researchers were able to contain and isolate contaminants trapped in the filter material.

###

Co-authors of the paper are Artur Khannanov, Vadim Nekljudov, Bulat Gareev and Airat Kiiamov, all of Kazan Federal University. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice. The Russian Government Program of Competitive Growth of Kazan Federal University supported the research.

Read the abstract for "Oxidatively Modified Carbon as Efficient Material for Removing Radionuclides From Water" at http://www.sciencedirect.com/science/article/pii/S0008622317300350.

Read the abstract for "Cs(I) and Sr(II) Sorption onto Graphene Oxide" at http://www.tandfonline.com/doi/full/10.1080/07366299.2016.1245067.

This news release can be found online at http://news.rice.edu/2017/01/19/treated-carbon-pulls-radioactive-elements-from-water/

Follow Rice News and Media Relations via Twitter @RiceUNews

Related materials:

Another tiny miracle: Graphene oxide soaks up radioactive waste: http://news.rice.edu/2013/01/08/another-tiny-miracle-graphene-oxide-soaks-up-radioactive-waste-2/

The Tour Group: http://tournas.rice.edu/website/

Rice Department of Chemistry: http://www.chem.rice.edu

Wiess School of Natural Sciences: http://natsci.rice.edu

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,910 undergraduates and 2,809 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for happiest students and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

Media Contact

David Ruth
david@rice.edu
713-348-6327

 @RiceUNews

http://news.rice.edu 

David Ruth | EurekAlert!

More articles from Materials Sciences:

nachricht The stacked colour sensor
16.11.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

nachricht Counterfeits and product piracy can be prevented by security features, such as printed 3-D microstructures
16.11.2017 | Karlsruher Institut für Technologie (KIT)

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>