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A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration
Published on: December 5, 2019
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Antimony isotope fractionation during complexation with humic acid
Shufang Zeng1, Weiqing Zhou1, Ziyi Zhou1
1School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
Journal of Hazardous Materials
|December 10, 2025
Summary
Antimony (Sb) adsorption onto humic acid shows minimal isotope fractionation at equilibrium. Early reaction stages reveal kinetic control, suggesting Sb isotopes can trace sources in organic-rich environments.
Area of Science:
- Environmental Chemistry
- Geochemistry
- Isotope Geochemistry
Background:
- Antimony (Sb) environmental fate is linked to dissolved organic matter (DOM) interactions.
- Isotope effects of Sb adsorption on DOM are not well understood.
Purpose of the Study:
- Investigate Sb(V) adsorption mechanism and isotope fractionation on humic acid (HA).
- Determine Sb isotope behavior during adsorption onto organic matter.
Main Methods:
- Kinetic, isothermal, and pH-dependent adsorption experiments.
- Extended X-ray absorption fine structure (EXAFS) spectroscopy.
- Antimony isotope analysis.
Main Results:
- Sb(V) binds to HA primarily via outer-sphere complexation.
- Negligible equilibrium isotope fractionation observed (Δ123Sb ≈ 0 ± 0.03‰).
- Transient enrichment of heavier Sb isotopes at early stages indicates kinetic control.
Conclusions:
- Sb isotope signatures can reflect sources in organic-rich environments.
- Sb isotopes are potential tracers for geogenic vs. anthropogenic sources and Sb cycling.
- First evidence of isotope fractionation during Sb(V)-HA adsorption, expanding Sb behavior knowledge beyond mineral studies.
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