| Popis: |
Publisher Summary This chapter reveals that the development of ligand-based nanocoatings, when bonded to the surface of high surface area, low-cost substrates, can transform those substrates, through surface functionalization chemistry, into a high capacity, target-specific adsorptive media capable of sequestering high concentrations of heavy metal contaminants. These monofunctional ligands bond covalently to the substrate and the metal contaminant. By changing the functional groups on the monofunctional ligand, a mixed wastestream, such as naturally occurring arsenic and uranium, can be separated. Once the nanocoated adsorptive media is exhausted, it can be recharged in situ by pouring a bifunctional self-assembling ligand over the filter bed. One end of the bifunctional ligand bonds to the metal already bonded to the filter media, leaving the other functional group, on the other end, available to bond the next layer of metal. The start-up company Crystal Clear Technologies has demonstrated that multiple layers of metal can be bonded to the same substrate to the point where the cumulative metal concentrations exceed 15 percent by weight and the metal can be reclaimed. |
