Polyoxometalate-Enhanced Oxidation of Organic Compounds by Nanoparticulate Zero-Valent Iron and Ferrous Ion in the Presence of Oxygen
TLDR
Comparable enhancements in oxidant yields are observed when nZVI or Fe(II) is exposed to oxygen in the presence of silica-immobilized POM, suggesting that coordination of iron by POM alters the mechanism of the Fenton reaction by converting the active oxidant from ferryl ion to hydroxyl radical.Abstract:
In the presence of oxygen, organic compounds can be oxidized by zerovalent iron or dissolved Fe(II). However, this process is not a very effective means of degrading contaminants because the yields of oxidants are usually low (i.e., typically less than 5% of the iron added is converted into oxidants capable of transforming organic compounds). The addition of polyoxometalate (POM) greatly increases the yield of oxidants in both systems. The mechanism of POM enhancement depends on the solution pH. Under acidic conditions, POM mediates the electron transfer from nanoparticulate zerovalent iron (nZVI) or Fe(II) to oxygen, increasing the production of hydrogen peroxide, which is subsequently converted to hydroxyl radical through the Fenton reaction. At neutral pH values, iron forms a complex with POM, preventing iron precipitation on the nZVI surface and in bulk solution. At pH 7, the yield of oxidant approaches the theoretical maximum in the nZVI/O2 and the Fe(II)/O2 systems when POM is present, suggesting th...read more
Citations
More filters
Journal ArticleDOI
Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application
Jianlong Wang,Le Jin Xu +1 more
TL;DR: In this paper, the authors summarize the formation reactions of the hydroxyl radical (·OH) and the mechanisms of pollutants degradation in six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton based reactions, and ozone-based processes.
Journal ArticleDOI
Magnetic Nanoscaled Fe3O4/CeO2 Composite as an Efficient Fenton-Like Heterogeneous Catalyst for Degradation of 4-Chlorophenol
Lejin Xu,Jianlong Wang +1 more
TL;DR: The high utilization efficiency of H(2)O(2), calculated as 79.2%, showed a promising application of the catalyst in the oxidative degradation of organic pollutants, and the reusability of Fe(3)O (4)/CeO (2) composite was investigated after six successive runs.
Journal ArticleDOI
Activation of persulfates by carbon nanotubes: Oxidation of organic compounds by nonradical mechanism
TL;DR: Carbon nanotubes (CNTs) have been found to activate persulfates (i.e., peroxymonosulfate and peroxydisulfate) into reactive species that are capable of oxidizing organic compounds in water.
Journal ArticleDOI
Activation of Persulfates by Graphitized Nanodiamonds for Removal of Organic Compounds
Hongshin Lee,Hyoung Il Kim,Seunghyun Weon,Wonyong Choi,Yu Sik Hwang,Jiwon Seo,Chang Ha Lee,Jae-Hong Kim +7 more
TL;DR: Results indicate that radical intermediates such as sulfate radical anion and hydroxyl radical are not majorly responsible for this persulfate-driven oxidation of organic compounds, and suggest that G-ND plays a critical role in mediating facile electron transfer from phenol to persulfates.
Journal ArticleDOI
Fenton-like degradation of 2,4-dichlorophenol using Fe3O4 magnetic nanoparticles
Lejin Xu,Jianlong Wang +1 more
TL;DR: In this paper, the effect of different reaction parameters such as initial pH, H2O2 dosage, Fe3O4 nanoparticles addition, initial concentration of 2,4-DCP and temperature on two-stage first-order kinetics of degradation was studied.
References
More filters
Journal ArticleDOI
Critical Review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (⋅OH/⋅O− in Aqueous Solution
TL;DR: In this article, the rate constants for over 3500 reaction are tabulated, including reaction with molecules, ions and other radicals derived from inorganic and organic solutes, and the corresponding radical anions, ⋅O− and eaq−, have been critically pulse radiolysis, flash photolysis and other methods.
Journal Article
Critical review of rate condtants for reaction of hydrated electrons, hydrogen atoms and hydroxyl radicals in aqueous solution
Journal ArticleDOI
Catalysis by Heteropoly Acids and Multicomponent Polyoxometalates in Liquid-Phase Reactions
Book
Standard Potentials in Aqueous Solution
TL;DR: Standard Potentials in Aqueous solution as mentioned in this paper is a collection of thermodynamic data from the IUPAC Commissions onElectrochemistry and Electroanalytical Chemistry, and it is a valuable supplementarytext for undergraduate and graduate-level chemistry students.
Related Papers (5)
Factors affecting the yield of oxidants from the reaction of nanoparticulate zero-valent iron and oxygen.
Iron-catalyzed oxidation of arsenic(III) by oxygen and by hydrogen peroxide: pH-dependent formation of oxidants in the Fenton reaction.
Stephan J. Hug,Olivier X. Leupin +1 more