Abstract:

Nanoscale zero-valent iron (nZVI) is a kind of effective material for remediation of polluted soil and water. It can be used to remove hexavalent chromium, Cr (Ⅵ), which is toxic and easily mobile in the environment. In recent years, many researches have studied impacts of temperature, pH value, initial concentration, etc. in the systems, while dissolved oxygen (DO) is seldom to discuss. Herein, we compared zero-valent iron (ZVI) and nZVI for Cr(Ⅵ) removal in the presence or absence of oxygen in water. We focused on the effect of DO on removal of Cr(Ⅵ) by nZVI. The shortterm batch experiment showed that nZVI is significantly more effective in removing Cr (Ⅵ) than ZVI due to large specific surface area and high activity of nano particles. Oxygen enhances Cr(Ⅵ) removal in water by nZVI in that more production of Fe²⁺, goethite, magnetite, etc. can be useful in this process and iron oxides can easily adsorb Cr(Ⅵ) on the surface of nZVI in the presence of oxygen.

Key words: nanoscale zero-valent iron, dissolved oxygen, Cr(Ⅵ), adsorption