Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Palladium beats iron for TCE cleanup: Palladium-gold nanoparticles clean TCE a billion times faster than iron filings

Photos.com/Rice University
Photos.com/Rice University

Abstract:
In the first side-by-side tests of a half-dozen palladium- and iron-based catalysts for cleaning up the carcinogen TCE, Rice University scientists have found that palladium destroys TCE far faster than iron -- up to a billion times faster in some cases.

Palladium beats iron for TCE cleanup: Palladium-gold nanoparticles clean TCE a billion times faster than iron filings

Houston, TX | Posted on June 27th, 2012

The results will appear in a new study in the August issue of the journal Applied Catalysis B: Environmental.

TCE, or trichloroethene, is a widely used chemical degreaser and solvent that's found its way into groundwater supplies the world over. The TCE molecule, which contains two carbon atoms and three chlorine atoms, is very stable. That stability is a boon for industrial users, but it's a bane for environmental engineers.

"It's difficult to break those bonds between chlorine and carbon," said study author Michael Wong, professor of chemical and biomolecular engineering and of chemistry at Rice. "Breaking some of the bonds, instead of breaking all the carbon-chlorine bonds, is a huge problem with some TCE treatment methods. Why? Because you make byproducts that are more dangerous than TCE, like vinyl chloride.

"The popular approaches are, thus, those that do not break these bonds. Instead, people use air-stripping or carbon adsorption to physically remove TCE from contaminated groundwater," Wong said. "These methods are easy to implement but are expensive in the long run. So, reducing water cleanup cost drives interest in new and possibly cheaper methods."

In the U.S., TCE is found at more than half the contaminated waste sites on the Environmental Protection Agency's Superfund National Priorities List. At U.S. military bases alone, the Pentagon has estimated the cost of removing TCE from groundwater to be more than $5 billion.

In the search for new materials that can break down TCE into nontoxic components, researchers have found success with pure iron and pure palladium. In the former case, the metal degrades TCE as it corrodes in water, though sometimes vinyl chloride is formed. In the latter case, the metal acts as a catalyst; it doesn't react with the TCE itself, but it spurs reactions that break apart the troublesome carbon-chlorine bonds. Because iron is considerably cheaper than palladium and easier to work with, it is already used in the field. Palladium, on the other hand, is still limited to field trials.

Wong led the development of a gold-palladium nanoparticle catalyst approach for TCE remediation in 2005. He found it was difficult to accurately compare the new technology with other iron- and palladium-based remediation schemes because no side-by-side tests had been published.

"People knew that iron was slower than palladium and palladium-gold, but no one knew quantitatively how much slower," he said.

In the new study, a team including Wong and lead author Shujing Li, a former Rice visiting scholar from Nankai University, China, ran a series of tests on various formulations of iron and palladium catalysts. The six included two types of iron nanoparticles, two types of palladium nanoparticles -- including Wong's palladium-gold particle -- and powdered forms of iron and palladium-aluminum oxide.

The researchers prepared a solution of water contaminated with TCE and tested each of the six catalysts to see how long they took to break down 90 percent of the TCE in the solution. This took less than 15 minutes for each of the palladium catalysts and more than 25 hours for the two iron nanoparticles. For the iron powder, it took more than 10 days.

"We knew from previous studies that palladium was faster, but I think everyone was a bit surprised to see how much faster in these side-by-side tests," Li said.

Wong said the new results should be helpful to those who are trying to compare the costs of conducting large-scale tests on catalytic remediation of TCE.

Additional co-authors include former Rice undergraduate Chris Romanczuk '12, former Rice graduate student Yu-Lun Fang and Nankai University faculty members Zhaohui Jin and Tielong Li. The research was supported by the National Science Foundation, the Welch Foundation and the China Scholarship Council.

####

About Rice University
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 known for its "unconventional wisdom." With 3,708 undergraduates and 2,374 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 has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 4 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to www.rice.edu/nationalmedia/Rice.pdf.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Jade Boyd
713-348-6778

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

A copy of the study is available at:

Related News Press

News and information

Nanoribbon film keeps glass ice-free: Rice University lab refines deicing film that allows radio frequencies to pass September 16th, 2014

Effective Nanotechnology Innovations to Receive Mustafa Prize September 16th, 2014

‘Small’ transformation yields big changes September 16th, 2014

Elusive Quantum Transformations Found Near Absolute Zero: Brookhaven Lab and Stony Brook University researchers measured the quantum fluctuations behind a novel magnetic material's ultra-cold ferromagnetic phase transition September 15th, 2014

Chemistry

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

Rice chemist wins rare NSF Special Creativity Award: Grant extension will bolster Zubarev's effort to produce gold nanorods September 8th, 2014

Iranian, Spanish Scientists Produce Recyclable Catalyst by Using Nanoparticles September 3rd, 2014

Production of Toxic Ion Nanosorbents with High Sorption Capacity in Iran August 17th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Nanoribbon film keeps glass ice-free: Rice University lab refines deicing film that allows radio frequencies to pass September 16th, 2014

‘Small’ transformation yields big changes September 16th, 2014

'Squid skin' metamaterials project yields vivid color display: Rice lab creates RGB color display technology with aluminum nanorods September 15th, 2014

Fonon at Cutting-Edge of 3D Military Printing: Live-Combat Scenarios Could See a Decisive Advantage with 3D Printing September 15th, 2014

Discoveries

Nanoribbon film keeps glass ice-free: Rice University lab refines deicing film that allows radio frequencies to pass September 16th, 2014

‘Small’ transformation yields big changes September 16th, 2014

Rice rolls 'neat' nanotube fibers: Rice University researchers' acid-free approach leads to strong conductive carbon threads September 15th, 2014

Simple, Cost-Effective Method Proposed for Synthesizing Zinc Oxide Nanopigments September 15th, 2014

Announcements

Nanoribbon film keeps glass ice-free: Rice University lab refines deicing film that allows radio frequencies to pass September 16th, 2014

Effective Nanotechnology Innovations to Receive Mustafa Prize September 16th, 2014

‘Small’ transformation yields big changes September 16th, 2014

Simple, Cost-Effective Method Proposed for Synthesizing Zinc Oxide Nanopigments September 15th, 2014

Environment

Iranian Nano Scientists Create Flame-Resistant Polymers September 13th, 2014

NanoStruck has a High Recovery Rate on Mine Tailings: retrieval of up to 96% of Gold, 88% of Silver and 86% of Palladium September 12th, 2014

Nanostruck announces 87.6% recovery of 56 GMS/ton silver tailings samples September 12th, 2014

Boosting armor for nuclear-waste eating microbes September 12th, 2014

Research partnerships

Elusive Quantum Transformations Found Near Absolute Zero: Brookhaven Lab and Stony Brook University researchers measured the quantum fluctuations behind a novel magnetic material's ultra-cold ferromagnetic phase transition September 15th, 2014

NEI Corporation and PneumatiCoat Technologies Sign Agreement to Jointly Develop and Market New Materials for Lithium-ion Batteries September 12th, 2014

Advanced Light Source Sets Microscopy Record| Berkeley Lab Researchers Achieve Highest Resolution Ever with X-ray Microscopy September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE