title: Kinetic study for phenol degradation by ZVI-assisted Fenton reaction and related iron corrosion investigated by X-ray absorption spectroscopy.
abstract: In this study, we investigated phenol degradation via zero-valent iron (ZVI)-assisted Fenton reaction through kinetic and spectroscopic analysis. In batch experiments, 100 mg/L of phenol was completely degraded, and 75% of TOC was removed within 3 min under an optimal hydrogen peroxide (H2O2) concentration (50 mM) via the Fenton reaction. In the absence of H2O2, oxygen (O2) was dissolved into the solution and produced H2O2, which resulted in phenol degradation. However, phenol removal efficiency was not very high compared to external H2O2 input. The Fenton reaction rapidly occurred at the surface of ZVI, and then phenol mobility from the solution to the ZVI surface was the rate determining step of the whole reaction. The pseudo-second order adsorption kinetic model well describes phenol removal, and its rate increased according to the H2O2 concentration. X-ray absorption spectroscopic analysis revealed that iron oxide (Fe-O bonding) was formed on ZVI with [H2O2] > 50 mM. A high concentration of H2O2 led to rapid degradation of phenol and caused corrosion on the ZVI surface, indicating that Fe(2+) ions were rapidly oxidized to Fe(3+) ions due to the Fenton reaction and that Fe(3+) was precipitated as iron oxide on the ZVI surface. However, ZVI did not show corroded characteristics in the absence of H2O2 due to the insufficient ZVI-assisted Fenton reaction and oxidation of Fe(2+) to Fe(3+).
authors.affiliation: Decontamination and Decommissioning Research Division, Korea Atomic Energy Research Institute (KAERI), Daedeok-daero 989-111, Yuseong-gu, Daejeon 34057, Republic of Korea. Electronic address: ihyoon@kaeri.re.kr.
authors.forename: In-Ho
authors.initials: IH
authors.lastname: Yoon
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daehak-ro 291, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Gursong
authors.initials: G
authors.lastname: Yoo
authors.affiliation: Korea Institute of Geoscience and Mineral Resources (KIGAM), 124, Gwahank-ro, Yuseong-gu, Daejeon 34132, Republic of Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Hong
authors.affiliation: Future Environmental Research Center, Korea Institute of Toxicology (KIT), 17, Jeigok-gil, Munsan-eup, Jinju, Gyeongsangnam-do 52834, Republic of Korea.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Pohang Accelerator Laboratory (PAL), 80 Jigokro-127-beongil, Nam-gu, Pohang 37673, Gyeongbuk, Republic of Korea.
authors.forename: Min Gyu
authors.initials: MG
authors.lastname: Kim
authors.affiliation: Decontamination and Decommissioning Research Division, Korea Atomic Energy Research Institute (KAERI), Daedeok-daero 989-111, Yuseong-gu, Daejeon 34057, Republic of Korea.
authors.forename: Wang-Kyu
authors.initials: WK
authors.lastname: Choi
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daehak-ro 291, Yuseong-gu, Daejeon 34141, Republic of Korea. Electronic address: jwyang@kaist.ac.kr.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Yang
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D010636:Phenols / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy; D014961:X-Ray Diffraction
chemical_list: C045076:Fenton's reagent; D010636:Phenols; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron
keywords: EXAFS; Fenton reaction; Hydrogen peroxide; XANES; XRD; ZVI