Granular iron oxide as a catalyst in chemical oxidation of organic contaminants

摘要

Oxidation of organic contaminants, such as chlorobenzene and n-chlorobutane, by hydrogen peroxide (H_2O_2) and ozone (O_3) in water has improved significantly in the presence of granular iron oxide mineral, goethite. It is believed that the hydroxyl radical produced by the catalytic decomposition of H_2O_2 or O_3 over the goethite surface was responsible of oxidation of the surface-bound organic compounds. The oxidation rate of the organics was directly proportional to the dosage of the catalyst and the dosage of the oxidant, H_2O_2 or O_3. The apparent rate of the oxidation reactions was determined by the intrinsic reaction rates on the catalyst surface rather than the mass-transfer rates of the oxidant and the organic compound. The catalytic process was also effective in removing the total organic carbon (TOC) of the solutions indicating that it is capable of achieving complete mineralization.