ABSTRACT
The existence of pollutants in surface water, particularly from hazardous heavy metals and metalloids such as lead (Pb), mercury (Hg), chromium (Cr), cadmium (Cd) and arsenic (As) discharged from industrial establishments, must be minimized, as some of these heavy metals are carcinogens and some can induce social problems. These metals can enter humans through the food chain: either by direct consumption of heavy metal–laden aquatic organisms or by consuming heavy metal–contaminated crops irrigated by polluted water. A treatment is therefore required in ensuring less heavy metal ions’ pollution to the environment. One treatment method is by reduction process, and so far reduction of Cr(VI) has been shown to be successful via photocatalysis technology utilizing nanostructured semiconductor oxide. In this chapter, we present a brief overview on heavy metal pollutions and the possibilities of treatment with 1-D ?-Fe2O3 nanowires. The nanowires can be formed by thermal oxidation of iron and hence the topic is reviewed in this chapter. The growth of the nanowires can be explained by surface diffusion process, quasi-liquid process and stress-driven mechanism, and the formation can be as rapid as a few minutes and can be done at low temperature (< 400°C).
