Antimony (Sb) is a recognized priority pollutant with toxicity that is influenced by its migration and transformation processes. Oxidation of Fe(II) to Fe(III) oxides, which is a common phenomenon in the environment, is often accompanied by the formation of Mn(III/IV) and might affect the fate of Sb. In this study, incorporated Mn(III) and sorbed/precipitated Mn(III/IV) associated with lepidocrocite were prepared by adding Mn(II) during and after Fe(II) oxidation, respectively, and the effects of these Mn species on Sb fate were investigated. Our results indicated that the association of these Mn species with lepidocrocite obviously enhanced Sb(III) oxidation to Sb(V), while concomitantly inhibiting Sb sorption due to the lower sorption capacity of lepidocrocite for Sb(V) than Sb(III). Additionally, Mn oxide equivalents increased in the presence of Sb, indicating that Sb oxidation by Mn(III/IV) associated with lepidocrocite was a continuous recycling process in which Mn(II) released from Mn(III/IV) reduction by Sb(III) could be oxidized to Mn(III/IV) again. This recycling process was favorable for effective Sb(III) oxidation. Moreover, Sb(V) generated from Sb(III) oxidation by Mn(III/IV) enhanced Mn(II) sorption at the beginning of the process, and thus favored Mn(III/IV) formation, which could further promote Sb(III) oxidation to Sb(V). Overall, this study elucidated the effects of Mn(III/IV) associated with lepidocrocite arisen from Fe(II) oxidation on Sb migration and transformation and revealed the underlying reaction mechanisms, contributing to a better understanding of the geochemical dynamics of Sb.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jes.2021.08.001 | DOI Listing |
Chemosphere
November 2024
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. Electronic address:
J Hazard Mater
December 2024
School of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, PR China; Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing & Finishing, Wuhan Textile University, Wuhan 430200, PR China. Electronic address:
In the field of peroxymonosulfate (PMS) activation technology, there is a pressing need to reduce PMS consumption and enhance its utilization rate. The present study demonstrates that the introduction of dissolved oxygen (DO) into the Mn(II)-nitrilotriacetic acid (NTA)-activated PMS system significantly enhances the degradation efficiency of sulfadiazine and increases the PMS utilization rate from approximately 15.0 to 41.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
November 2024
Fachbereich Chemie und Forschungszentrum OPTIMAS, RPTU Kaiserslautern-Landau, 67663 Kaiserslautern, Germany.
Manganese complexes exhibit a rich redox chemistry, usually accompanied by structural reorganization during the redox processes often followed by ligand dissociation or association. The push-pull ligand 2,6-diguanidylpyridine (dgpy) stabilizes manganese in the oxidation states +II, +III, and + IV in the complexes [Mn(dgpy)] ( = 2-4) without change in the coordination sphere in the condensed phase [Heinze et al., , 61, 14616].
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2023
Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT 59812.
The hydroxylation of C-H bonds can be carried out by the high-valent Co(µ-O) complex supported by the tetradentate tris(2-pyridylmethyl)amine ligand via a Co(µ-O)(µ-OH) intermediate (). Complex can be independently generated either by H-atom transfer (HAT) in the reaction of with phenols as the H-atom donor or protonation of its conjugate base, the Co(µ-O) complex . Resonance Raman spectra of these three complexes reveal oxygen-isotope-sensitive vibrations at 560 to 590 cm associated with the symmetric Co-O-Co stretching mode of the CoO diamond core.
View Article and Find Full Text PDFWater Res
May 2023
Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States; Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States; Department of Microbiology, University of Tennessee, Knoxville, Tennessee 37996, United States; Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee 37996, United States; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States. Electronic address:
Bisphenol A (BPA) is a high production volume chemical with potential estrogenic effects susceptible to abiotic degradation by MnO. BPA transformation products and reaction mechanisms with MnO have been investigated, but detailed process understanding of Mn(III)-mediated degradation has not been attained. Rapid consumption of BPA occurred in batch reaction vessels with 1 mM Mn(III) and 63.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!