Nanostructured materials possess novel hybrid properties characteristic of neither the molecular nor the bulk solid state with sized dependent behavior. Nonoporous materials, characterized by well-defined pore and/or cavities size in nanometer scale with unique molecular sieving capabilities and ultrahigh surface area suitable as hosts and templates for fabrication of nanoscale devices. We will discuss the fundamental principle for designing synthesis and characterization nanoporous adsorbents for environmental remediation. For example, lead ions in soils and stormwater run-off from small arms firing range (SAFR) is a concern of national proportion. Various adsorption technologies have been studied to obviate the problem of lead species releases to the environment . We present in this study the equilibrium adsorption of aqueous Pb2+ ions by nanocomposites HMS, MCM-41, and MCM-48. Kinetics and isotherm models were prepared, and the effects of pH 2 to pH 12, competing ions, and 25°C, 35°C and 45°C temperatures, on performance were investigated. Isothermic measurements fit Freundlich and Langmuir models. Average percent Pb2+ removal for HMS, MCM-41, and MCM-48 was 94%, 97%, and 97%, respectively. Ionic competition reduced Pb2+ removal by HMS, but enhanced MCM-41 and MCM-48 performance. HMS began to release Pb2+ ions below a pH of 6 and MCM-41 and 48 began to release Pb2+ below a pH of 4. MCM-41 demonstrated potential for SAFR applications with the greatest range of pH, and a consistent performance in the presence of competing ions and increasing temperatures.
 Small Arms Range Lead Management Issues: Activated Carbon, Molecular Sieves (5A and 13X) and Naturally Occurring Zeolites as Lead Adsorbents. Tarek M. Abdel-Fattah, Larry K. Isaacs and Kelly B. Payne, Federal Facilities Environmental Journal, 14(2), 113 (2003)
Department of Biology, Chemistry and Environmental Science
Christopher Newport University
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