Dissolved organic matter promoted hydroxyl radical formation and phenanthrene attenuation during oxygenation of iron-pillared montmorillonites.
Chemosphere
; 352: 141264, 2024 Mar.
Article
en En
| MEDLINE
| ID: mdl-38244867
ABSTRACT
The oxygenation of Fe(II)-bearing minerals for hydroxyl radicals (HOâ¢) formation and contaminant attenuation receives increasing attentions. However, information on dissolved organic matter (DOM) with different types, concentrations, and molecular weights (MWs) in manipulating HO⢠formation and contaminant attenuation during mineral oxygenation remain unclear. In this study, four iron-pillared montmorillonites (IPMs) and two DOM samples [e.g., humic acids (HA) and fulvic acids (FA)] were prepared to explore the HO⢠formation and phenanthrene attenuation during the oxygenation of IPMs in the presence or absence of DOMs. Results showed that iron-pillared and high-temperature calcination procedures extended the interlayer domain of IPMs, which provided favorable conditions for a high HO⢠production from 1293 to 14537 µmol kg-1. The surface-absorbed/low crystalline Fe(â
¡) was the predominant Fe(â
¡) fractionations for HO⢠production, and presence of DOMs significantly enhanced the HO⢠production and phenanthrene attenuation. Moreover, regardless of the types and concentrations, the low MW (LMW, <1 kDa) fraction within DOM pool contributed highest to HO⢠production and phenanthrene attenuation, followed by the bulk and high MW (HMW-, 1 kDaâ¼0.45 µm) fractions, and FA exhibited more efficient effects in promoting HO⢠production and phenanthrene attenuation than HA. The fluorescent spectral analysis further revealed that phenolic-like fluorophores in LMW-fraction were the main substances responsible for the enhanced HO⢠production and phenanthrene attenuation. The results deepen our understandings toward the behaviors and fate of aquatic HO⢠and contaminants, and also provide technical guidance for the remediation of contaminated environments.
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MEDLINE
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Fenantrenos
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En
Revista:
Chemosphere
Año:
2024
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Article
País de afiliación:
China