The installation is part of a full-scale field test of PGClear by Rice University, DuPont Central Research and Development and Stanford University. The researchers say PGClear can gently but quickly destroy some of the world’s most pervasive and problematic pollutants. It uses a combination of palladium and gold metal to break down hazardous compounds like vinyl chloride, trichloroethene, also known as TCE, and chloroform into nontoxic byproducts.
DuPont’s 6-by-8-foot unit contains valves and pipes that will carry groundwater to a series of tubes that each contain thousands of pellets of palladium-gold catalyst. The pellets, which are about the size of a grain of rice, spur a chemical reaction that breaks down chloroform into nontoxic methane and chloride salt.
The technology originated from basic scientific research at Rice during a 10-year, federally funded initiative to use nanotechnology to clean the environment.
Chlorinated compounds were widely used as solvents for many decades, and they are common groundwater contaminants the world over, according to Michael Wong, Rice professor of chemical and biomolecular engineering and the lead researcher on the PGClear project. These compounds are also extremely difficult to treat inexpensively with conventional technology, the researchers say.
The problem-solving for this technology began at the nanoscale. The Rice team was working with nanoscale catalysts when it developed the technology that would ultimately become PGClear. The scale of the technology was subsequently enlarged to permit use in conventional reaction systems for field implementation.
Wong has been working on the project since 2001. DuPont contacted Wong about his award-winning research in 2007 and proposed developing a scalable process to use the palladium-gold catalysts to treat other chlorinated pollutants like chloroform and vinyl chloride.
In March, an EPA report claimed that Google employees were exposed to high levels of a cancer-causing TCE at one of the company’s satellite campuses on a Superfund toxic waste site.
Between mid-November and mid-January, after workers disabled part of the air ventilation system at an office complex in Mountain View, Calif., levels of TCE in two Google office buildings exceeded concentrations deemed safe by the EPA, according to a report by the federal agency, obtained by the Center for Investigative Reporting.