Iron-induced association between selenium and humic substances in groundwater from deep sedimentary formations

Terashima, Masanao; Endo, Takashi R.; Kimuro, Shingo; Beppu, Hikari; Nemoto, Kazuaki; Amano, Yuki

doi:10.1080/00223131.2022.2111376

Cited by 2 publications

(2 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…of the NOM. ,,, Studies have also proposed that since NOM is a negatively charged species at near-neutral pH, the complexation of negatively charged selenate and selenite with NOM requires metal cation bridging to form a ternary complex (Se-M-NOM, where M is a polyvalent cation). Formation of such ternary complex has been hypothesized when selenite was added to the humic-rich brown lake water, upon sorption of selenite onto organic component separated from the bulk soil of >200 and 200–50 μm size fraction of grassland soil, and in soil extract, and groundwater system . Martin et al have tested the efficacy of different polyvalent metal cations (e.g., Fe 3+ , Cr 3+ , Al 3+ , and Ga 3+ ) for the ternary complexation of Se species with NOM.…”

Section: Introductionmentioning

confidence: 99%

“…Formation of such ternary complex has been hypothesized when selenite was added to the humic-rich brown lake water, 18 upon sorption of selenite onto organic component separated from the bulk soil of >200 and 200−50 μm size fraction of grassland soil, 23 and in soil extract, 28 and groundwater system. 29 Martin et al 24 have tested the efficacy of different polyvalent metal cations (e.g., Fe 3+ , Cr 3+ , Al 3+ , and Ga 3+ ) for the ternary complexation of Se species with NOM. They have found only Fe 3+ and Cr 3+ to be effective for such complexation, although their behavior in the complexation was different.…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanistic Insight into the Abiotic Interactions of Selenate and Selenite with Natural Organic Matter

Dalai,

Sivan,

Husain

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

Natural organic matter (NOM) decreases the selenium (Se) mobility in soil and sediment. Biotic dissimilatory reduction of selenate and selenite and assimilation of the reduced Se species into biomolecules are thought to be primarily responsible for this decreased Se mobility. However, the possibility of Se immobilization due to the abiotic interaction of Se species with NOM is still poorly understood. Equilibrating selenate and selenite with a model NOM (Pahokee peat soil), followed by X-ray absorption spectroscopic analysis, this study shows that the NOM can abiotically reduce highly mobile selenate into relatively less mobile selenite. NOM can sorb Se species, especially selenite, considerably. Preloading of the NOM with Fe(III) increases the sorption of selenite and selenate by several orders of magnitude. Modeling of the Se and Fe K-edge EXAFS data revealed that Se species are sorbed to NOM due to indirect complexation with the organically complexed Fe(O,OH) 6 octahedra through the corner-( 2 C) and edge-sharing ( 1 E) and direct complexation with the oxygencontaining functional groups of the NOM. This study concludes that the abiotic reduction and complexation of the Se species with NOM can be the additional or alternative route of Se immobilization in the NOM-rich soil and sediment.

show abstract