Environmental Activity at the National Labs

December 05 / January 06 Volume 3 Number 6

Print this Article

E-mail this Article

Los Alamos National Laboratory

Microhole Drilling
Los Alamos is using small-bore drills to make "microholes" to monitor subsurface CO2. Coiled-tubing technologies eliminate handling of segmented large-diameter drill pipes. Microholes with diameters of 2-3/8 inch and 1-3/4 inch may lead to savings of nearly 60 percent (discounting labor savings). Microhole technology can reduce the cost of deploying instruments in the subsurface while improving measurement quality. This can greatly enhance safe CO2 containment at geologic sequestration sites.

Española Basin Aquifer 3D Model
LANL hydrologists have developed a computer simulation of the entire Española Basin aquifer in New Mexico (approximately 100 square kilometers). The model is sufficiently detailed to capture small-scale variations in hydrostratigraphy and stresses on the aquifer caused by pumping. The model is being used to predict the rate of future water level declines due to pumping and to predict ultimate fate of contaminants in the regional aquifer.

Modeling Clouds
Climate researchers are working on the "cloud problem." It has long been known that clouds are difficult to simulate accurately with computers. The conventional "slab-cloud" model assumes for simplicity that clouds are uniform slabs. To go beyond the slab-cloud model, Los Alamos researchers have developed a physics-based method for estimating heating and cooling at every point inside a 3-D cloud as it is dynamically modeled and an anomalous diffusion model for the mean radiative flux through the whole atmospheric column. These advanced cloud models have successfully explained the variability of new photon path length observations using oxygen-line spectroscopy at very high resolution.

Pacific Northwest National Laboratory

Preventing Pandemics
Zoonotic diseases, those diseases transmitted between animals and humans, have the potential to cause worldwide epidemics. These diseases include well-advertised examples such as bird flu. For humans, these diseases can be deadly. For the food industry, these diseases can spell economic disaster. PNNL scientists are investigating rapid and pre-symptomatic screening methods to help prevent outbreaks associated with poultry, beef and other livestock.

The laboratory is also finding new, non-invasive ways to rapidly identify infected animals or humans so that valuable resources can be used on those needing treatment, and not the worried well. Studies at PNNL on biomarkers in sweat or saliva could lead to rapid diagnostic assays that detect biomarkers for naturally occurring or intentionally propagated zoonotic diseases, such as anthrax.

Nanomaterials: Friend or Foe?
The use and production of nano-sized materials is increasing rapidly, offering great promise for major advances in medicine, manufacturing, electronics and many other areas of science and commerce. Still, the potential health effects of these tiny particles, 100,000 times smaller than the width of a hair, are generally unknown.

Could nanoparticles be part of the next wave of revolutionary medical treatments? Or, are they part of an upcoming threat to human and ecosystem health? Or, does the answer lie somewhere in-between? Scientists at PNNL are answering questions around the impact of these materials on human respiratory systems.

Sandia National Laboratories

Desalination
Researchers, with fellow members of the Joint Water Reuse & Desalination Task Force, will be studying the best ways to desalinize and make potable ocean water, subsurface brines and wastewater. The California Department of Water Resources recently granted Sandia and its partners $1 million for the study. Among possibilities to be studied will be alternatives to disposing of waste—€”extremely salty water—€”after the desalination process. The waste could be dumped into the ocean, put in ponds for evaporation, or injected into the subsurface. the program seeks to identify and develop new, cost-effective technologies for removing salts and micropollutants from water. Current desalination technologies are effective at removing contaminants from water, but are as yet too expensive for most communities to purchase and operate.

Breakthrough Photovoltaics
Rising energy costs and instability in regions producing most of the world's fossil fuels have refocused attention on the need for alternative, renewable energy sources. While the cost of solar cells has dropped over the past several decades, the technology is still not cost-effective for on-grid applications (homes, businesses). Sandia researchers have developed a breakthrough photovoltaic cell design and fabrication process that eliminates the current-collection grids from the front surface of the cell. The new process uses a laser to drill holes through the silicon substrate and form conductive channels from the front to the rear surface. This advance allows the electric power to flow to the back surface where the backside wiring carries the current away. Unlike conventional cells with wiring on the front that inefficiently blocks sunlight, these laser-drilled holes make the cells more efficient by exposing more of the top surface of the solar cells to sunlight. These back-contact cells also reduce assembly cost by eliminating the front-to-back connection step, and they offer a more aesthetically-pleasing product for the consumer.

This new technology is now being manufactured by Advent Solar, an Albuquerque startup. The company was founded by Rusty Schmit, former president of Photowatt International, and James Gee, the Sandia researcher who conceived of the cell design and developed the novel fabrication process that eliminates the current-collection grids from the front surface of the cell. The company began operations in 2003 after licensing Sandia's back-contact photovoltaic cell technology.

The new solar cell design offers a more efficient and less expensive option than other cells currently available in the marketplace.

Hydrogen Sensors
The emerging hydrogen economy will require a large number of hydrogen sensors for safety and efficiency. The Robust, Wide-Range Hydrogen Sensor developed at Sandia is the only one of its kind to offer both low-range and high-range hydrogen measurement capability on the same chip, virtually eliminating false readings and making it an ideal candidate for a variety of government and commercial applications.

H2scan Corporation of Valencia, Calif., has licensed Sandia's sensor technology and through a CRADA has developed a small in situ sensor with the capability of detecting hydrogen concentrations between 10 parts per million and 100 percent. H2scan has three retail products in commercial use and has delivered sensors to over 200 government and industry customers.

Lawrence Livermore National Laboratory

Restoring Paradise
Lawrence Livermore scientists are working to minimize radiation exposure for residents and former inhabitants who wish to return to the Marshall Islands in the North Pacific, where the United States conducted 67 atmospheric tests of nuclear weapon designs between 1945 and 1958. Livermore's Marshall Islands Dose Assessment and Radioecology Program continues research begun about 30 years ago—€”characterizing radiological conditions on islands contaminated by years of above-ground nuclear testing and developing strategies to minimize radiological exposure to people wishing to resettle. The program also supports Marshallese efforts to implement radiation protection programs for residents wishing to track their exposure to radionuclides from fallout contamination that still lingers on the islands.

Understanding Risks
Scientists in the Energy and Environment and Chemistry and Materials Science directorates are helping to further the Department of Energy's understanding of the risks posed by radioactive contamination of groundwater from underground nuclear tests at the Nevada Test Site. DOE's goals for the Underground Test Area Project are to identify the areas where radiological contamination from past underground nuclear tests threatens the groundwater, predict the movement of potentially contaminated groundwater, and define the contaminant boundaries or the extent of radionuclide migration. The Livermore team is measuring the concentrations of radionuclides in the groundwater and modeling in detail how radionuclides from specific underground tests enter the water and migrate through geological formations. Their data become the starting point for computer models developed to examine large regions of the site—€”up to hundreds of square kilometers in area.

Tracking Air Pollution in Yosemite
LLNL's Center for Accelerator Mass Spectrometry (CAMS) is frequently called on to investigate environmental issues using its tools and expertise in mass spectrometry. In 2002, CAMS and Colorado State University researchers analyzed air samples to determine the source of reduced visibility in Yosemite National Park. They found that organic aerosol concentrations in Yosemite were significantly above the historical average, and probably came from forest fires in Oregon and Southern California during the sampling. CAMS scientists are currently measuring carbon levels in bacterial biomass and soil organic matter to help determine how carbon moves through the soil, an important factor in determining how best to capture heat-trapping carbon in the atmosphere and help minimize global warming.

Cleaning Up Groundwater
The lab has developed new techniques for characterizing and cleaning up groundwater at Superfund hazardous waste sites. These activities in the 1990s led to the development and transfer to U.S. industry of novel technologies for water treatment, including dynamic underground stripping for rapid groundwater remediation and capacitive deionization (CDI) for removal of a variety of contaminants.

Water Treatment Technologies
Present water treatment technologies, such as membrane filtration or reverse osmosis, are energy-intensive and expensive, in part because they remove many compounds in addition to contaminants. Technologies that selectively remove only undesired contaminants can improve water treatment operating costs and energy efficiencies enough to allow many small communities and rural households to use local freshwater supplies that currently do not meet potable standards because of a single contaminant (e.g., arsenic, selenium, perchlorate, uranium, or nitrate).

LLNL has made breakthroughs in the fundamental science of separations technology, developing complex molecular-level computer simulation models to understand the chemical transport of contaminants through different types of materials. The objective is to design materials that are "tuned" to selectively attach to and remove compounds of choice. These concepts are tested using a diversity of media, including membranes, ion-exchange resins, aerogels, and aerogel composites. (An area of special expertise at LLNL, aerogels are high-surface area, low-density materials that can adsorb large amounts of contaminants per unit weight and volume.) To date, Livermore scientists have been able to identify, fabricate and test designer materials (for example, chemical functional groups on membranes) to selectively remove arsenic, metals, radioactive compounds, and hydrocarbons from water. LLNL also has developed a spectrum of energy-efficient portable treatment units. These units, designed to have low capital and operating costs and to operate at remote sites, can be configured to run on renewable energy sources such as solar power.

The laboratory is also helping municipalities in California's Central Valley that need to treat nitrate- or arsenic-contaminated groundwater. The water is naturally hard and prone to precipitating minerals, creating plugging problems in the low-cost filter media needed to eliminate the nitrate and arsenic. LLNL is using its geochemical modeling expertise to determine ways to prevent the minerals from forming, allowing these communities to efficiently use these low-cost media rather than higher cost alternatives to meet arsenic and/or nitrate standards.

Improving Desalination Processes
LLNL has been developing technologies to improve the energy efficiency of desalination processes for more than 20 years. In the 1990s, the laboratory licensed an innovative approach to capacitive deionization (CDI) using aerogels to desalt water. In 1995, this technology received an R&D 100 Award as one of the top 100 technology innovations of the year. A licensee of LLNL's capacitive deionization technology has just announced an agreement for development and manufacturing of the key aerogel material that is the heart of the company's product.

Next-generation and spinoffs from this original technology are under development, including a concept based on the electrodialysis (ED) process. ED is more energy efficient than reverse osmosis at removing salt from brackish water, but it is still not cost effective enough to treat large volumes of marginally impaired waters. Laboratory scientists are working on developing "smart" membranes for ED. They would be designed to selectively remove only the contaminant of interest. Accordingly, the process would be far more efficient and lower energy costs by 50 percent or more.

Better Sensor Technologies
LLNL is applying its expertise in sensor technologies and its national and homeland security capabilities to help water utilities and agencies. In support of the Department of Homeland Security, the lab has recently performed an assessment of sensors and systems currently available to utilities for detection of biological and chemical contamination in water distribution systems. More generally, unique facilities at Livermore are available for real-time detection and response to hazardous releases. They include the National Atmospheric Release Advisory Center (NARAC), the Biosecurity and Nanosciences Laboratory, the Biodefense Knowledge Center and the Forensic Science Center.

In addition, Livermore is at the forefront of developing new sensors for chemical and biological hazards, including detectors for single molecules of deadly pathogens, and rapid biohazards detection by polymerase chain reaction (PCR). Over the past three years, three LLNL-developed biological agent detection systems have earned R&D 100 Awards. Coupling its expertise in electronics miniaturization and materials science, the laboratory is also developing high-resolution portable chemical sensors, including a sensor for arsenic, based on selective membrane technology.

Water Monitoring
LLNL is applying innovative analytical and modeling tools to monitor and manage water resources. For example, the laboratory has state-of-the-art facilities for age-dating tritium (helium-3) and methods for low-level detection of tracers and contaminants. Integrated with high-resolution hydrologic models, these capabilities are aiding California in assessing groundwater vulnerability to MTBE and other contaminants.

LLNL also develops database management tools for water agencies to use to assess and manage contaminated water resources. GeoTracker, a GIS tool developed by the laboratory and managed by the state of California, provides a public online database of groundwater compositions for all leaking underground fuel tank sites and public wells. Scientists are currently working with a California water agency and the National Water Research Institute on a tool to balance contributions from multiple water sources and manage arsenic loading to a municipal water supply. Another software tool allows water managers to visualize sources, uses and disposal of water in systems from watershed to national scales, as demonstrated by use of U.S. Geological Survey data to diagram water flows in the United States and in some states.