Found in solid-rocket fuel, roadside flares and fireworks, perchlorate is a dangerous contaminant that can disrupt thyroid function by interfering with the uptake of iodine. Infants and fetuses are believed to be particularly at risk from the effects of perchlorate exposure.
Because perchlorate is readily soluble in water, it can be transported vast distances in groundwater or rivers. A plume of contaminated groundwater from a manufacturing plant near Las Vegas, for example, reached the Colorado River and spread throughout the Southwest. Cleanup could take decades. "Perchlorate has been recognized as a significant environmental contaminant in U.S. water supplies, and its physical and chemical properties pose a serious challenge for remediation," said John Shapley, a professor of chemistry at Illinois and co-developer, with graduate student Keith Hurley, of the new catalyst.
Efforts at remediation using naturally occurring microorganisms or existing pump-and-treat technology are too complicated, too energy intensive or too slow to be practical, Shapley said.
The new catalyst is composed of two metals – palladium and rhenium – supported on activated carbon. The catalyst operates at room temperature under normal atmospheric pressure, and does not dissolve in water.
"In catalytic operation, the rhenium removes an oxygen atom from the perchlorate molecule in what is called an atom transfer reaction," Hurley said. "Meanwhile, the palladium activates the gaseous hydrogen atoms so they will react with the freed oxygen. What's left is harmless chloride and water." The catalytic reaction continues as long as there is both hydrogen gas and perchlorate contaminant present.
"While current technologies – such as ion exchange systems – can concentrate and remove perchlorate from water, they cannot destroy it," said Shapley, who will describe the new catalyst at the national meeting of the American Chemical Society, to be held in San Francisco, Sept. 10-14. "Our catalyst would take a concentrated stream of perchlorate and get rid of it altogether."
James E. Kloeppel | EurekAlert!
Nanobot pumps destroy nerve agents
21.08.2018 | American Chemical Society
How do muscles know what time it is?
21.08.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Medical Engineering
21.08.2018 | Physics and Astronomy
21.08.2018 | Power and Electrical Engineering