Heating-Induced Redox Property Dynamics of Peat Soil Dissolved Organic Matter in a Simulated Peat Fire: Electron Exchange Capacity and Molecular Characteristics

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Peatlands store one-third of the world's soil organic carbon. Globally increased fires altered peat matter chemistry, yet redox property and molecular dynamics peat-dissolved (PDOM) during remain poorly characterized, limiting our understanding postfire biogeochemical processes. Clarifying these dynamic changes is essential for effective peatland fire management. This study demonstrates temperature-dependent in electron exchange capacity (EEC) PDOM by simulating burning, significantly affecting microbial iron reduction. At low temperatures (200-250 °C), EEC remains constant releasing more phenolic moieties to enhance electron-donating (EDC). Higher (500 °C) diminish 90% consuming phenolic-quinone moieties. Pyrolytic (pyPDOM) contributes 40% soil, with this contribution declining at higher temperatures. Phenolic-quinone primary redox-active pyPDOM. Fourier transform ion cyclotron resonance mass spectrometry analysis shows that EDC depends on types than abundance, monophenol-like molecules (

Язык: Английский

Electrochemical Characterization of Pyrogenic Carbons: Implications for Degradation of Groundwater Contaminants with Carbon-Based Amendments

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Апрель 15, 2025

Pyrogenic carbons (PCs) are important mediators of biogeochemical redox reactions and contribute to contaminant degradation in some remediation methods. Contaminant by electron transfer from PC is influenced its conductivity storage capacity, atom involving atomic hydrogen, but resolving their contributions difficult. In this study, we developed a method modify working electrodes with agarose-stabilized thin films PCs used them characterize reactivity using 2,4,6-trinitrotoluene (TNT) as model several electrochemical Chronoamperometry showed that TNT reduction rates increase increasing temperature, impedance spectroscopy because the heterogeneous rate constants (k0) inversely correlated resistivity (Rp) films. As result, like biochars, which have higher charge resistance (Rct), give lower rates, whereas Rct activated faster reduction. Current H2O/H+ H2 (HER) was significant only for low Rp PC-films on Pt electrodes. The reactive intermediates involved HER react preferentially quinonoid moieties PC, thereby competing limiting at overpotentials (

Язык: Английский

Chemical and Optical Distinctions Between Elemental Carbon Subcategories Char-EC and Soot-EC: Insights from a Haze Event in North China

Environmental Pollution, Год журнала: 2025, Номер unknown, С. 126306 - 126306

Опубликована: Апрель 1, 2025

Язык: Английский