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Lab News -- August 19, 2005

September 2 , 2005

LabNews 09/02/2005PDF (650KB)

Sandia researchers study methods for removing arsenic from drinking water to help meet new EPA standards

By Chris Burroughs

Over the next several months a team of Sandia researchers led by Malcolm Siegel (6118) will be studying different methods of arsenic removal at the Desert Sands Mutual Domestic Water Consumers Association (MDWCA) in Anthony in southern New Mexico.

A ceremony marking the start of the project was held Aug. 26 at the utility’s main well site. On hand were representatives from Sandia, Sen. Pete Domenici’s office, the New Mexico state legislature, and the water utility.

The arsenic research is sponsored by the Arsenic Water Technology Partnership. The partnership is a consortium of Sandia, the Awwa Research Foundation (AwwaRF), and WERC, a consortium for environmental education and technology development. Domenici secured the funding for the project through DOE as chairman of the Senate Energy and Water Development Appropriations Subcommittee.

MOU signing

At the Aug. 26 ceremony Sandia and the MDWCA signed a memorandum of understanding (MOU) to begin the research.
Signing for Sandia was John Merson, deputy director for Geoscience & Environment Center 6100. The utility representative was Rosaura Pargas, president.

“The Desert Sands project will supplement a full-scale demonstration by the US EPA [Environmental Protection Agency] for evaluation of a removal technology that uses granular iron oxide to filter arsenic from water,” Malcolm says. “As water is pumped through the system, arsenic sticks to the iron oxide. The Desert Sands MDWCA wants Sandia to compare the performance of the [iron oxide] material they are currently using to other adsorptive media. We should be able to give them some practical advice based on what we learn.”

Best absorptive material

The Sandia field team includes lead engineer Malynda Aragon and field technicians Randy Everett and William Holub (all 6118). Malynda anticipates they will test between eight and 12 different arsenic removal systems at the Anthony site. “We’ll be looking at which material best adsorbs arsenic to compare how often the adsorptive media needs to be changed,” she says.

The treatment system, including plastic columns filled with adsorptive material and monitoring equipment, was built at Sandia and was recently relocated to the Desert Sands utility.

Desert Sands serves a population of 1,535 from two wells in a rural community along the New Mexico-Texas state line, north of El Paso. It has a new water treatment plant built by Severn Trent Corp. that uses the iron oxide treatment method.
The Anthony research is a follow-up to work in Socorro, N.M., where the Sandia team tested five arsenic removal technologies at a geothermal spring. The pilot test in Socorro compared five innovative technologies. These treatment processes were chosen from more than 20 candidate technologies that were reviewed by teams of technical experts at Arsenic Treatment Technology Vendor Forums organized by Sandia and held at the 2003 and 2004 New Mexico Environmental Health Conferences.

Congressional support and design of the Arsenic Water Technology Partnership was developed under Domenici’s leadership to help small communities comply with the new EPA drinking water standard for arsenic. The new regulation, which goes into effect in January 2006, reduces the maximum contaminant level (MCL) from 50 micrograms per liter (µg/L) to 10 µg/L and is intended to reduce the incidence of bladder and lung cancers caused by exposure to arsenic.

Arsenic levels high in west

Levels of naturally occurring arsenic in the southwestern US often exceed the new MCL. The new compliance requirements will affect small communities that lack the appropriate treatment infrastructure and funding to reduce arsenic to newly required levels.

Malcolm says the goals of the program are to “develop, demonstrate, and disseminate information about cost-effective water treatment technologies in order to help Native Americans and small communities in the Southwest and other parts of the country comply with the new EPA standard.”

Besides the Socorro and Desert Sands experiments, additional demonstrations, based on technologies reviewed at vendor forums and developed by DOE labs or in laboratory studies managed by AwwaRF, are also being considered in consultation with the New Mexico Environment Department, the EPA, the Indian Health Service, the Navajo Nation EPA, and the Interstate Technology Regulatory Council.

WERC, a consortium of research institutions in New Mexico, will evaluate the economic feasibility of the technologies, work on technology transfer activities, and conduct educational outreach.

Whether a current proposal to phase in stricter arsenic requirements over years takes hold or not, there will still be a need to help communities modify systems to perform better, Malcolm says. Scientists are also beginning to look at other contaminants that may be regulated in the future.

“We need to stay ahead of the curve so communities can invest in proven systems that will address multiple contaminants,” he says. -- Chris Burroughs

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Disintegrating asteroid’s dust monitored for first time; Sandia optical sensors contributed

By Neal Singer

The object — a little less than 10 meters across — entered Earth’s atmosphere on Sept. 3, 2004, traveling at 13 kilometers per second.

The space-based infrared sensors of the US Department of Defense detected it at an altitude of 75 kilometers, descending off the coast of Antarctica.
DOE visible-light sensors built by Sandia noticed the intruder when it became a fireball — thus identifying itself as an asteroid — at approximately 56 kilometers above Earth,

Five infrasound stations, built to detect nuclear explosions anywhere in the world, registered its acoustic waves; these were analyzed by researchers at Los Alamos National Laboratory.
NASA’s multispectral polar orbiting sensor imaged the debris cloud formed by the disintegrating space rock.
It was one of the largest meteoroids to have entered the Earth’s atmosphere in the past decade. (Later analysis showed that its original solar orbit is similar to that of near-Earth asteroids of a particular family, the Aten group.)

Some 7.5 hours after the initial observation, a cloud of anomalous material was detected in the upper stratosphere over Davis Station in Antarctica by ground-based lidar.

These were the first direct measurements ever made of such meteoritic “smoke.”

Something unusual about the cloud

“We noticed something unusual in the data,” says Andrew Klekociuk, a research scientist at the Australian Antarctic Division. “We’d never seen anything like this before, [a cloud that] sits vertically and things blow through it. It had a wispy nature, with thin layers separated by a few kilometers. Clouds are more consistent and last longer. This one blew through in about an hour.”

There was certainly something unusual about the cloud. It was too high for ordinary water-bearing clouds (32 kilometers instead of 20 km) and too warm to consist of known manmade pollutants (55 degrees warmer than the highest expected frost point of human-released solid cloud constituents). The cloud could, of course, have been made of dust from a solid rocket launch, but the asteroid’s descent and the progress of its resultant cloud had been too well observed and charted; the pedigree, so to speak, of the cloud was clear.

What was really unusual about the cloud was the size of its particles. Computer simulations agreed with sensor data that the particles’ mass, shape, and behavior identified them as asteroid constituents roughly 10 to 20 microns in size.

Micron-sized particles are big enough to reflect sunlight, cause local cooling, and play a major role in cloud formation.
Scientists formerly had paid little attention to dust from meteoroids, assuming that the burnt matter disintegrated into nanometer-sized particles that did not affect Earth’s environment. Some researchers (and science fiction writers) were more interested in the damage that could be caused by the intact portion of a large asteroid striking Earth.

“Our observations suggest that [meteoroids exploding] in Earth’s atmosphere could play a more important role in climate than previously recognized,” write Klekociuk and other researchers, including Sandia’s Dick Spalding (5740), in a paper published last week in the journal Nature (Aug. 25 issue).

Klekociuk, along with researchers from the University of Western Ontario, the Aerospace Corp., LANL, and Sandia had found evidence that dust from the asteroid burning up as it descended through Earth’s atmosphere formed a cloud of micron-sized particles significant enough to influence local weather in Antarctica.

Volcanic eruptions from the sky

Says Dee Pack of Aerospace, “This asteroid deposited 1,000 metric tons in the stratosphere in a few seconds, a sizable perturbation.” Every year, he says, 50 to 60 meter-sized asteroids hit Earth.

Micron-sized meteoroid dust could be a factor in climate simulations because meteroids entering Earth’s atmosphere are extremely reduced by the fireball caused by the friction of their passage. The solid mass reduced to dust may be as much as 90 to 99 percent of the original asteroid.

Peter Brown at the University of Western Ontario, initially contacted by Klekociuk, helped analyze data and did theoretical modeling. He points out that climate modelers might have to extrapolate from this one event to its larger implications.
“[Meteoroid dust could be modeled as] the equivalent of volcanic eruptions of dust, with atmospheric deposition from above rather than below,” he says. The new data on micron-sized particles “has much greater implications for [extraterrestrial visitors] like Tunguska.” He was referring to an asteroid or comet that exploded 8 kilometers above the Stony Tunguska River in Siberia in 1908. About 2,150 square kilometers were devastated, but little formal analysis was done on the atmospheric effect of the dust that must have been deposited in the atmosphere.

Preventing nuclear war

The capabilities of defense-related sensors to distinguish between the explosion of a nuclear bomb and an asteroid fireball that releases similar amounts of energy — in this case, about 13 kilotons — could provide an additional margin of world safety. Without that information, a country that experienced a high-energy asteroid burst that penetrated the atmosphere more deeply might lead a hair-trigger military response unit to believe either that its country has been attacked or that a nearby country is testing a nuclear weapon.

The Sandia sensors’ primary function is to observe nuclear explosions anywhere on Earth. Their evolution to include meteor fireball observations came when Dick Spalding recognized that ground-based processing of data might be modified to record the relatively slower flashes due to asteroids and meteoroids. Sandia computer programmer Joe Chavez (5724) wrote the program that filtered out signal noise caused by variations in sunlight, satellite rotation, and changes in cloud cover to realize the additional capability. The Sandia data constituted a basis for the energy and mass estimate of the asteroid, says Dick.
Longer research papers being prepared from the same data for other journals are expected to discuss possible negative effects on the planet’s ozone layer, says Pack. -- Neal Singer

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CINT facilities, enhanced by thousand-year-old Chaco culture decorative style, nearing completion

By Neal Singer

A two-story-high, 450-foot-long wall surfaced with flat-chipped rock evocative of Chaco Canyon has been erected north of the Kirtland Eubank Gate and west of Eubank Blvd.

The curved, two-foot-thick wall cuts across the three laboratory wings of the new core facility of the Center for Integrated Nano-technologies. The wall’s function is not structural but to serve as an advertisement rooted in New Mexico’s history.

“We’re trying to create a working environment that is attractive to the brightest scientists [from everywhere],” says Sandia project manager Bill Hendrick (10824) of the architectural enhancement, as well as other features in the new structure, funded by the DOE Office of Science.
An imitation of the walls of Chaco Canyon structures built nearly a thousand years ago, the curved wall (for reasons of cost, built internally of steel) gives the core building a distinctly different look from other buildings in the technology park to the south.

“We wanted to juxtapose high-tech with what we understood of New Mexico’s history: today’s cutting edge with yesteryear’s,” says Bill Wells, senior architectural project manager of Arizona-based HDR, the building’s design firm.
That thoughtfulness includes the creation of casual meeting spaces between the three major lab divisions for “scientists, who may not be the most extroverted, to mingle and chat,” says Paul O’Donnell, project manager for general contractor Hensel Phelps.

The design, which radiates the three labs west from the curved stone wall façade like spokes from a wheel, includes sophisticated characterization capabilities in the northernmost wing; physical, chemical, and biological synthesis facilities in the middle wing; and clean rooms for nano/micro integration to the south.

The design, says CINT user program manager Neal Shinn (1131), was arrived at through meetings among Los Alamos and Sandia engineers and scientists, who discarded the idea of a more common rectilinear building for the current structure.
CINT is a joint venture of Sandia and Los Alamos, with the 96,000-square-foot core facility expected to act as headwaters from which work will flow as appropriate to LANL’s 35,000-square-foot gateway facility, or to Sandia’s gateway facility, housed in Bldg. 897 at the southeast corner of Area 1.

Construction is on schedule at both labs, with the core facility expected to be physically completed by late November and the LANL gateway by mid-January. The latter is a feat in itself, considering that construction proceeded through LANL’s administratively ordered shut- down and 38 days of bad weather, says LANL Gateway project manager Ross Garcia.

“We changed strategy to start [raising] steel on footings in parallel with [laying] the slab,” rather than laying all the slab and then proceeding to raise steel, he says. “The rain was puddling up.”

“It’s important the buildings are ready at [roughly] the same time,” says Jerry Hands (10800), general technical manager of the proj- ect. “Equipment would have to be purchased separately or stored if all buildings weren’t ready for them. Buying two or three items [at a time] gets [CINT] quantity discounts.”

All equipment should be installed, and all DOE qualifications met, by March, says Jerry.

Sandia and LANL researchers have worked together before and often, but CINT is the first jointly built project. Jerry, who has headed the construction of National Ignition Facility buildings (not the laser itself) at Lawrence Livermore, and other projects at Sandia and LANL, doesn’t take the new challenge lightly. He divides his time between the two labs to spot problems early. “If one construction project succeeds and the other fails,” he says, “I’ve failed.”

Teams of engineers and scientists from both labs decide jointly on equipment that will populate each facility. Researchers from both labs will work at all CINT Facilities.

CINT is one of five nanotechnology centers funded by DOE’s Office of Science. More than 60 nanotechnology research projects are already ongoing at LANL and Sandia, funded by “jumpstart” funds from the Office of Science and scattered through the two giant labs. -- Neal Singer

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