Adsorption and oxidation of PCP on the surface of magnetite: Kinetic experiments and spectroscopic investigations

Abstract : The oxidation of pentachlorophenol (PCP) on the surface of magnetite used as heterogeneous catalyst has been investigated under various experimental conditions (initial substrate concentration, H2O2 dose, solid loading and temperature) at neutral pH and correlated with the adsorption behavior. The surface reactivity of magnetite was evaluated by conducting the kinetic study of both H2O2 decomposition and PCP oxidation experiments. The occurrence of the optimum values of H2O2 and magnetite concentrations for the effective degradation of PCP could be explained by the scavenging reactions with H2O2 or iron oxide surface. The surface interactions with PCP in the absence and the presence of oxidant can be well described by Langmuir and Langmuir–Hinshelwood models, respectively. All batch experiments indicate that Fenton-like oxidation of PCP was controlled by surface mechanism reaction and the species compete with each other for adsorption on a fixed number of surface active sites. The apparent degradation rate was dominated by the rate of intrinsic chemical reactions on the oxide surface rather than the rate of mass transfer. Raman analysis suggested that the sorbed PCP was removed form magnetite surface at the first stage of oxidation reaction. The mineralization determined by TOC abatement was completed after 7 d, while total dechlorination was achieved at 4 d treatment time. The first reaction of PCP oxidation should be the dechlorination since 90% of chloride was formed at the first 30 h corresponding to the total disappearance of parent compound. All X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Mössbauer spectroscopy and chemical analyses showed that the magnetite catalyst exhibited low iron leaching, good structural stability and no loss of performance in second reaction cycle.
Complete list of metadatas

https://hal.univ-lorraine.fr/hal-01899678
Contributor : Mustapha Abdelmoula <>
Submitted on : Friday, October 19, 2018 - 5:00:45 PM
Last modification on : Thursday, April 11, 2019 - 3:30:02 PM

Identifiers

Collections

Citation

Xiaofei Xue, Khalil Hanna, Mustapha Abdelmoula, Nansheng Deng. Adsorption and oxidation of PCP on the surface of magnetite: Kinetic experiments and spectroscopic investigations. Applied Catalysis B: Environmental, Elsevier, 2009, 89 (3-4), pp.432 - 440. ⟨10.1016/j.apcatb.2008.12.024⟩. ⟨hal-01899678⟩

Share

Metrics

Record views

39