One of the most promising technologies owes its inception to the discovery that
chlorinated hydrocarbon solvents in contaminated groundwater samples were unstable in
the presence of certain steel and iron-based well casing materials, a discovery made by
Gillham and co-workers in the early 1990’s (Elliott et al, 2007). Since then the field of
scientific research has exploded with investigations into the remediation capacity and
reductive ability of zero-valent iron (ZVI), and more recently nano-scale zero-valent iron
(nZVI). Zero-valent iron, seen in a core shell model shown in Figure 2.1, is essentially
elemental iron that has an excess of electrons owing to the nature of iron being
characteristically stable as Fe2+ and Fe3+. It is in this zero-valent form that it acts as an
electron donor, facilitating the reduction of a variety of contaminants. At the nano-scale
(particle diameter