Degradation of aniline catalyzed by heterogeneous Fenton-like reaction using iron oxide/SiO2

The immobilized iron oxides on quartz granules (SG) were withdrawn from the fluidized bed reactors and then used to catalyze hydrogen peroxide (H2O2) from heterogeneous generating hydroxyl radical (center dot OH). The effects of the reaction conditions including the initial pH, SG loading, and concentrations of aniline on aniline degradation were examined. The experimental result showed that the decomposition of H2O2 decreased with increased concentrations of H2O2 once the concentration of H2O2 increased to more than 0.05 M. The rate constant of aniline degradation (kobs) increased when increasing amounts of SG were added. The evidence proved the initial pH = 46 in the solution is an optimum condition for the degradation of aniline using SG as a heterogeneous catalyst. The aniline degradation suggested that center dot OH initially attacked the aromatic ring-NH2 bonding of aniline, and the ring opening of aniline was then formed. Results demonstrate that the iron oxides are recyclable, cheaper, and more active. (c) 2012 American Institute of Chemical Engineers Environ Prog, 32: 187-192, 2013