Ph.D. / Environmental Science and Engineering / In the past decade, permeable reactive barriers containing zero-valent iron metal (FePRBs) have emerged as the most significant new technology for the treatment of groundwaters contaminated with chlorinated organic compounds and, more recently, other organic contaminants such as 2,4,6-trinitrotoluene (TNT). Principle issues relating to the design, implementation, and monitoring of FePRBs include the rates of contaminant transformation, the resulting distribution of products, and the potential changes in FePRB performance due to aging of the iron material. Each of these issues is, at its root, a problem of chemical kinetics. In this thesis, commonly observed kinetic expressions for contaminant transformation are derived. Analyses of the simplifications involved in these derivations indicate that the forms of the rate laws are correct (either exactly or approximately) over a wider range of conditions than previously expected and that reaction rates may respond in unexpected fashion to changes in concentrations of reacting species or iron loading. These theoretical developments are applied to experimental investigations of product distribution and FePRB longevity for the treatment of TNT contaminated groundwaters.

Thesis (Ph.D.)--OGI School of Science & Engineering at OHSU, 2005. / Includes bibliographical references.