NEWARK , February 10, 2000 -Technology developed by New Jersey Institute of Technology (NJIT) to "surgically" remediate underground hazardous wastes without digging them up has been awarded a third patent. The technology is available through two licensees, McLaren Hart Incorporated, Warren, N.J., and ARS Technologies, Highland Park, N.J.

      In a demonstration project at the Hanford, Wash. Atomic Energy Plant, the technology was successfully used in combination with a vitrification process to show how simulated underground "radioactive" waste can be permanently fixated in glass "in situ" or on site to prevent it from leaching into the environment.

      More recently, the technology proved highly effective in removing spilled jet fuel from aquifers at McGuire Air Force Base, NJ.

      The new patent, which involves the use of dry media such as powders, is one of several in situ methods based on pneumatic fracturing. Pneumatic fracturing was developed and initially patented in 1991 by an NJIT research team led by Civil and Environmental Engineering Professors John Schuring, Paul Chan and Project Engineer Thomas Boland. It was brought to commercialization with the aid of ARS Technologies (formerly Accutech Remedial Systems), the first company licensed to use the technology.

      ARS Technologies has since employed it at 71 sites in North America, including 23 states. The firm is now making the technology available in Japan, Italy and Australia.

      Also supporting the research have been various governmental agencies, including the Environmental Protection Agency, the Department of Energy, the U.S. Air Force, and U.S. Geological Survey.

      In addition, support has come from other private sector firms including AT&T, Battelle Pacific Northwest Laboratories, BP America, Elf Atochem, Envirogen, Malcolm Pirnie, Inc.; Union Carbide, and URS Grener-Woodward Clyde.

      Pneumatic fracturing is similar to hydraulic fracturing, a process long used in the oil industry in which water is pumped into an almost exhausted well to "crack" the geologic formation and force out the remaining oil or gas.

      In pneumatic fracturing, air or gas is used in place of water to crack the formation, dilate it, and either pump or vacuum hazardous waste out of the ground.

      The depth and width of the underground area to be "fractured" can be precisely controlled to allow for what is virtually a surgical removal of hazardous underground waste. "We are able to place it 40, 50 or more feet down and control how wide we want it to be," notes Professor Schuring.

      The depth range of pneumatic injection is more than adequate since most polluted sites are the result of surface leaking.

      Pneumatic fracturing is particularly useful in cleaning more difficult sites -- those with low permeability such as soil or bedrock. While such sites can be dug up and removed, it is far cheaper and less hazardous - since workers aren't exposed -- to use pneumatic fracturing to clean them in situ.

      Pneumatic fracturing makes it possible to inject other clean-up mediums into the ground. The researchers recently earned a second patent for bio-remediation techniques using bacteria genetically engineered to digest certain waste substances, oxygen, pH (acidity) modifiers and nutrients to encourage growth of indigenous bio-organisms to degrade contamination and normalize the soil.

      Notes Schuring, "Most of the 'nasties' involved in hazardous waste contamination are organic, which means that somewhere there's a microorganism that can digest it and render it harmless."

      At the Hanford Atomic Energy Plant, the NJIT researchers worked in partnership with the Department of Energy and the Battelle Memorial Institute, Columbus, OH., which together had developed the vitrification process in the 1980's.

      In the process, glass frit - tiny glass particles -- and graphite -- an electrical conductor -- are sprinkled on the radioactive waste material. The pile is then heated to 2,000 degrees Centigrade by an electric power source.

      This causes the glass frit to melt around the radioactive waste material and isolate it from the environment for a million years or more, according to the researchers.

      While the original Battelle vitrification process dealt only with surface contamination, the NJIT research team expanded its potential use to radioactive underground wastes. A hole was drilled into the soil formation, and patented equipment was lowered to inject air, and shatter and dilate the geologic formation.

      Next, the NJIT patented technique was used to create a plate-like formation of frit and graphite. Electrodes were then lowered to the plate and high power applied to melt the soil, which also is mostly silica, turning it into glass. "This is the way the waste material can be encapsulated," notes Prof. Schuring.

      The NJIT researchers went down just 14 to 18 feet so the vitrified mass was shallow enough to be dug up and examined. But Schuring says that the pneumatic fracturing process can be used at depths of 50 ft. or more.

      Says the NJIT Professor, "Unlike some other hazardous wastes, you can't get rid of radioactivity using microorganisms, but you can isolate it from the environment."

      At McGuire Air Force Base, a bulk fuel storage facility had leaked jet fuel and heating oil into aquifers consisting of water and silty sand - an underground formation that presents problems because it is difficult to separate the hazardous liquid waste from the sand.

      To deal with it, the NJIT researchers worked with another industrial partner, McLaren Hart, the second firm licensed to use pneumatic fracturing. They fractured the underground formation and then injected layers of ceramic beads into the subsurface to form what's known as an "extended radius well."

      In such wells, fingerlike projections formed by the injected beads radiate out from the borehole, extend the range of the well's drainage area and enhance removal of the hazardous waste. "You extend the well's reach from maybe eight inches in diameter to six feet," says NJIT Graduate and McLaren Hart Senior Associate Engineer Debra Schnell, who worked on the project.

      At other sites, NJIT researchers have worked with McLaren/Hart to pneumatically inject peroxide and acetic acid into the subsurface to act as a reactive barrier to hazardous byproducts at coal mining plants. McLaren Hart was also an industrial partner with NJIT in developing the bio-remediation techniques mentioned earlier.

      More recently, NJIT researchers developed a computer modeling technique to employ pneumatic fracturing under structures. The computer model allows the researchers to predict very accurately the ground heave and stresses created by pneumatic fracturing, so that it can be used underneath a building or other structure with no significant effect on the structure.

      Again working with McLaren Hart, the NJIT team used computer modeling to predict the heave and stresses generated by pneumatic fracturing underneath a school building in Elizabeth, NJ. The model enabled them to safely extract hazardous materials underneath the school.

      Notes McLaren Hart Principal, James Mack, "The NJIT model accounts for all kinds of subsurfaces, from silt to clay to sedimentary rock to sand or sandy materials. You just insert your geology - the depth you are fracturing at, radiuses you want to achieve, and the model will predict heave and stress and tell you the pressures and flows you need to operate at to avoid any problems with the structure."

      A fourth and fifth patent in connection with pneumatic fracturing has been applied for, says the Professor. The fourth deals with pneumatic fracturing in combination with ultrasound to "scrub" stubborn contaminants from a site after the initial cleaning.

      "Say you've cleaned up 90% of the site," says Schuring. "The last 10% is the hardest to remove. But with ultrasound, you can energize the remainder to clean out virtually all of it. We see it as a valuable polishing technique."

      The fifth patent is aimed at protecting equipment used in pneumatic fracturing.

      NJIT is a public research university enrolling nearly 8,200 bachelor's, master's and doctoral students in 83 degree programs through its five colleges: Newark College of Engineering, New Jersey School of Architecture, College of Science and Liberal Arts, the School of Management and the Albert Dorman Honors College. Research initiatives include manufacturing, microelectronics, multimedia, transportation, computer science, solar astrophysics, environmental engineering and science, and architecture and building science.

      Yahoo! Internet Life magazine has ranked NJIT as America's "most wired" public university for two consecutive years, U.S. News and World Report's 1999 Annual Guide to America's Best Colleges ranked NJIT among the nation's top universities, and Money magazine's most recent issue of Best College Buys rated NJIT as the sixth best value among U.S. science and technology schools and among the top 100 overall. In September 1999, Mademoiselle ranked NJIT as the second most Internet-connected university in the nation.