We introduced superoxide as potassium superoxide (KO2) to artificial lake water containing dissolved organic matter (DOM) without or with introduced ferric iron complexes (DOM-Fe), and monitored the production rate of hydroxyl radicals as well as changes in the absorption and fluorescence properties of DOM. The introduction of KO2 decreased the absorption by DOM but increased the spectral slope coefficient of DOM more with complexed ferric Fe than without it. The introduction of KO2 increased the fluorescence of humic-like components in DOM without introduced ferric Fe but resulted in the loss of fluorescence in DOM with introduced ferric Fe. A single introduction of 13 µmol L–1 KO2 produced 10 µmol L–1 and 104 µmol L–1 hydroxyl radicals during a week-long experiment without and with the introduced DOM-Fe complexes, respectively. The production rate of hydroxyl radicals decreased exponentially with time but levelled off and continued several days in DOM with introduced ferric Fe. These findings suggest that in the presence of DOM-Fe complexes, superoxide can trigger an autocatalytic Fenton reaction that produces hydroxyl radicals and breaks down DOM.

Superoxide-driven autocatalytic dark production of hydroxyl radicals in the presence of complexes of natural dissolved organic matter and iron

Luca Carena;
2020-01-01

Abstract

We introduced superoxide as potassium superoxide (KO2) to artificial lake water containing dissolved organic matter (DOM) without or with introduced ferric iron complexes (DOM-Fe), and monitored the production rate of hydroxyl radicals as well as changes in the absorption and fluorescence properties of DOM. The introduction of KO2 decreased the absorption by DOM but increased the spectral slope coefficient of DOM more with complexed ferric Fe than without it. The introduction of KO2 increased the fluorescence of humic-like components in DOM without introduced ferric Fe but resulted in the loss of fluorescence in DOM with introduced ferric Fe. A single introduction of 13 µmol L–1 KO2 produced 10 µmol L–1 and 104 µmol L–1 hydroxyl radicals during a week-long experiment without and with the introduced DOM-Fe complexes, respectively. The production rate of hydroxyl radicals decreased exponentially with time but levelled off and continued several days in DOM with introduced ferric Fe. These findings suggest that in the presence of DOM-Fe complexes, superoxide can trigger an autocatalytic Fenton reaction that produces hydroxyl radicals and breaks down DOM.
2020
Inglese
Esperti anonimi
177
15
115782
115782
1
https://www.sciencedirect.com/science/article/pii/S0043135420303195?via=ihub
dissolved organic matter, iron, superoxide, hydroxyl radicals, production rate, absorption
FINLANDIA
REPUBBLICA POPOLARE CINESE
1 – prodotto con file in versione Open Access (allegherò il file al passo 6 - Carica)
262
4
Yihua Xiao; Luca Carena; Marja-Terttu Näsi; Anssi V. Vähätalo
info:eu-repo/semantics/article
partially_open
03-CONTRIBUTO IN RIVISTA::03A-Articolo su Rivista
File in questo prodotto:
File Dimensione Formato  
WR_Superoxide.pdf

Open Access dal 13/09/2024

Descrizione: articolo versione OA
Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 523.4 kB
Formato Adobe PDF
523.4 kB Adobe PDF Visualizza/Apri
2020_Xiao_Superoxide-driven autocatalytic dark production of HO radicals.pdf

Accesso riservato

Descrizione: articolo
Tipo di file: PDF EDITORIALE
Dimensione 862.17 kB
Formato Adobe PDF
862.17 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
2020_Xiao_SM.pdf

Accesso aperto

Descrizione: Supplementary Material
Tipo di file: PDF EDITORIALE
Dimensione 1.39 MB
Formato Adobe PDF
1.39 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1932291
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 37
  • ???jsp.display-item.citation.isi??? 36
social impact