Palladized zero-valent iron nanoparticles have shown to serve as catalysts for the breakdown of chlorinated hydrocarbons such as TCE and PCBs. Unfortunately these particles tend to be unstable largely due to agglomeration. This leads to vastly reduced reactivity and can also cause the particles to become trapped in sub-surface soil making them impractical for in situ use. In addition toxic intermediate by-products such as vinyl chloride are often produced using these particles. This technology modifies the preparation of bimetallic particles by adding a very low-cost stabilizer to prevent the nanoscale particles from agglomerating thereby maintaining their high surface area and reactivity. These stabilized nanoparticles demonstrate much higher reactivity than any other nanoparticles reported to date. In the treatment of TCE target concentrations were achieved in half the time as compared to the best reported results; for PCB over 80% was degraded within 100 hours compared to only 24% with unstabilized particles. In both cases no toxic intermediates were detected. Advantages: 1) Substantially increases the stability and reactivity of palladized zero-valent iron nanoparticles 2) Substantially increases the rate of dechlorination of chlorinated organic compounds: a 25-fold increase in initial degradation rate for TCE and an 80% elimination of PCBs in 100 hours have been shown. Patent: Subject of US Patent 7887880. This process has been experimentally verified with TCE and PCBs.
1) Reduces costs by enabling in situ treatment and by decreasing time and materials needed 2) Uses an inexpensive and environmentally friendly stabilizer 3) Prevents detectable formation of toxic intermediates 4) Prevents aggregation of nanoparticles allowing for in situ use