| Metal (hydr)oxide nanomaterials were synthesized using multiple synthesis techniques and the resulting media (titanate nanofibers, nanostructured spheres, and nanoparticle impregnated surfaces) were assessed for their potential to remove an important environmental pollutant in water (arsenate). The hypothesis was that nanotechnology offers the ability to control, characterize, and tailor the fabrication of materials for specific applications. Arsenic was selected as a representative environmental pollutant because of recent regulatory changes to a lower maximum contaminant level and its ability to form strong inner-sphere complexes with metal (hydr)oxides.; A comparison of sixteen types of metal (hydr)oxide nanomaterials indicated that titanium, zirconium, and iron (hydr)oxides were the most suitable materials because of their ability to remove arsenic and low toxicity of the base metal, which potentially be released into drinking water. Several metal (hydr)oxide nanomaterial media based upon titanium, zirconium and iron where synthesized to create hybrid ion exchange media, modified granular activated carbon media, metal (hydr)oxide nanofibers and extremely porous nanostructured spheres. Each synthesis platform produced nanomaterial media capable of being used in continuous flow configurations. Compared against each other and against existing commercial media for arsenic removal, the hybrid ion exchange media indicated higher arsenic sorption potential on a mass basis. The nanostructured zirconium oxide spheres indicated the highest arsenic sorption potential on a specific surface area basis and exhibited the most rapid pore diffusion, which was the limiting factor controlling overall mass transport. |
