Iron (Fe) isotope is a potential tool for tracking redox process and geochemical cycling in terrestrial environment. In this study, Fe concentration and its isotopic composition (δFe) in two typical Gleysol profiles (M1 and M2) were investigated to distinguish the processes which influence the variation of Fe isotopic composition during redox regimes in the Mun River Basin (MRB). Under oxidizing condition, Fe(II) was oxidized and re-precipitated to form Fe(III) (hydr)oxides zone (Fe nodule-containing zone) in two Gleysol profiles, leading to extremely light Fe isotopes in these zones. The results revealed that the lowest δFe value in Fe(III) (hydr)oxides zone was derived from the migration of light Fe isotopes in upper zone, and Fe(II) was retained and oxidized to Fe(III) (hydr)oxides. Proton-promoted dissolution and leaching were two critical factors leading to a decrease in Fe concentration, which were accompanied by the accumulation of heavy Fe isotopes in the upper zone of M1 profile. In M2 profile, light Fe induced by soil organic matter was accumulated in the topsoil with abundant organic matter. These findings provide comprehensive information of Fe isotopic fractionation and Fe cycling in soil profiles, which would contribute to the understanding of biogeochemical elemental cycling in terrestrial ecosystems.
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http://dx.doi.org/10.1016/j.scitotenv.2023.166664 | DOI Listing |
Chemistry
January 2025
Department of Chemistry, & Department of Bioscience & Biomedical Engineering, Indian Institute of Technology Bhilai, Durg, 491002, Chattisgarh, India.
The biotin-conjugated Fe(III) catecholate complex [Fe(BioL)], Fe(BioL) (BioLH=N-(3,4-dihydroxyphenethyl)-5-((3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide) is reported as targeted magnetic resonance imaging (MRI) contrast agents (CAs) to increase the payload for early-stage imaging of tumours. The high spin state and octahedral coordination of the Fe(III) complex are confirmed by EPR spectra and DFT optimized structure, respectively. The overall formation constant (log K) of Fe(BioL) is determined as 45, which is higher than the known, more stable complex [Fe(EDTA)].
View Article and Find Full Text PDFChemosphere
December 2024
V.V. Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3 Institutskaya str., 630090, Novosibirsk, Russian Federation. Electronic address:
Int J Biol Macromol
January 2025
Laboratory of Synthesis of Molecules with Biological Interest, University of Frères Mentouri Constantine 1, Constantine 25017, Algeria. Electronic address:
Monolignols, p-coumaryl alcohol (CouA), coniferyl alcohol (ConiA), and sinapyl alcohol (SinA), are the fundamental materials for lignin biosynthesis, a major component of lignocellulosic biomass. In the present study, we report a comprehensive analysis of the antioxidant properties of monolignols, using density functional theory (DFT) calculations. Under model physiological conditions, monolignols demonstrated a high hydroperoxyl radical scavenging capacity in polar media, with overall rate constants (k) ranging from 5.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
There is increasing concern about discoloration problems and microbial risks in drinking water. Until recently, how to control iron release and pathogenic bacterial growth in distribution pipes has been a knowledge gap. In our study, nanofiltration removed 13.
View Article and Find Full Text PDFNanoscale
November 2024
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, 110016, New Delhi, India.
Among the reported spinel ferrites, the p-block metal containing SnFeO is scarcely explored, but it is a promising water-splitting electrocatalyst. This study focuses on the reaction kinetics and atomic scale insight of the reaction mechanism of the oxygen evolution reaction (OER) catalyzed by SnFeO and analogous FeO. The replacement of FeIIOh sites with SnIIOh in SnFeO improves the catalytic efficiency and various intrinsic parameters affecting the reaction kinetics.
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