The aggregation and sedimentation of nanoparticles have been documented and examined in different systems. In recent years, these studies, particularly of metal oxides, have been focused on investigating two major implications of aggregation on the behavior of nanoparticles. For a number of these research works, one of the major goals was to define aggregation characteristics in order to predict and alter the fate and transport of nanoparticles in a given environment [1-5]. A study by Mylon et al. characterizing the influence of natural organic matter on the stability of hematite nanoparticles in the presence of electrolytes was intended to probe the colloidal properties of hematite in natural systems. The works of Chen et al. on alginate coated hematite confirmed that aggregation can be altered by the presence of a polymeric coating and by the type of co-solutes present in the solution. In terms of particle transport, Phenrat et al. compared the aggregation and sedimentation of nanoscale-zero valent iron (NZVI), magnetite and hematite to address issues regarding delivery of these reactive nanoparticles to subsurface organic contaminants. Recent work by Tiraferri et al. used guar gum to sterically stabilize the nanoparticles and enhance NZVI remediative property.