ALBUQUERQUE, N.M. — Three Sandia National Laboratories scientists who proposed methods to investigate or restore damaged environmental areas each have won grants of more than a million dollars from the Department of Energy to test the validity of their proposals.
The awards are among 135 distributed nationally to 52 universities and 11 national laboratories in a $47 million program by the energy department’s Environmental Management Science Program. The intent is to stimulate innovative fundamental research that will help the agency manage and dispose of radioactive and hazardous chemical waste. The prospective research “should address problems that are considered intractable without new knowledge,” according to a prospectus distributed by the agency.
Sandia principal investigators, who will each receive grants over a three-year period, are:
- Principal investigators Jess Wilcoxon and Jim Martin with program manager George Samara, $1.2 million, for a proposal to use sunlight to energize very small semiconductor particles held in suspension in liquid.Their idea calls for waste streams to flow over beds of these cheaply energy-charged particles to oxidize harmful organic chemicals into harmless carbon dioxide and diluted mineral acids.While solar detoxification is potentially much cheaper than incineration, previous solar efforts have been hampered because the active material of choice, titanium dioxide, can only absorb less than seven percent of available solar radiation and also tends to recombine subatomic elements — electrons and their ‘holes,’ or vacancies — that need to stay separate for the process to work. Materials substituted for titanium dioxide corroded. But recent work has produced non-corroding clusters of atoms whose ability to absorb different wavelengths of light is merely a function of the size of the cluster. The clusters also demonstrate a low rate of electron-hole recombinations. Use of this stable group of inorganic nanoparticles will be investigated by the project.
- Steve Conrad with co-principal investigator Bob Glass, $1.2 million, to combine realistic physical models with supercomputer data to study how harmful organic solvents sink into the water table, and analyze the effectiveness of three promising methods that might be used to remove them.The solvents might be degreasers or dry cleaning fluids drained into the ground through storage leaks or dumping done before the substances were known to be harmful. These solvents have sunk into aquifers, contaminating groundwater supplies.Using a glass-walled sandbox similar in appearance to an ant farm, the Sandia research group will evaluate capillary and gravitational action through a variety of soils as the solvent sinks. The team also will evaluate these cleanup techniques: surfactants, used to increase the solubility of organic solvents in water, speeding the cleanup; air sparging, which injects air down a well whose bottom opening has been drilled to lie beneath the trapped solvent. The air vaporizes the solvent, and the two rise together through the water table until they enter the waterless zone closer to the surface, when they exit through another well and the solvent is captured; and large-scale alcohol injection that reduces capillary forces within the pores of an aquifer, making it easier to force out the solvent. The evaluation technique, by more closely mimicking the conditions of the natural environment, should help lead to improved cleanup techniques.
- David Alumbaugh, with Sandians Bob Glass and Jim McCord, and two researchers at the University of Arizona, $2 million, to develop a hybrid scientific method that will determine the composition and rate of movement of harmful materials through arid sites above the water table.In the eastern part of the U.S., where ground table is closer to the surface, the movement of contaminants is easier to model and standard fluid modeling programs are used. In the dry Southwest and arid parts of Oregon, Idaho and Washington state, where the majority of contaminated sites are located, the water table is deeper, making it more difficult to model the flow of contaminants through the unsaturated zone. “It becomes more of a non-linear problem,” said Alumbaugh.His group’s proposal combines information about soil’s electrical resistance with statistics about geology and with moisture and contaminant distribution in soil samples into a complex computer code.
DOE officials say the Environmental Management Science Program is the first of its kind in bringing together scientists who have the desire to understand the whys and hows of everything in the universe with the engineers who must methodically complete defined tasks.
Proposed research is expected to contribute to environmental management and restoration actions that would decrease risk for the public and workers, provide opportunities for major cost reductions, and reduce time required to achieve major cleanup actions.
The investment itself resulted from congressional interest in encouraging longer term research to ultimately reduce clean-up costs of environmentally damaged areas.