TY - JOUR
T1 - Degradation of perfluorooctanoic acid adsorbed on Fe-zeolites with molecular oxygen as oxidant under UV-A irradiation
AU - Qian, Lin
AU - Georgi, Anett
AU - Gonzalez-Olmos, Rafael
AU - Kopinke, Frank Dieter
N1 - Funding Information:
We thank Mireia Arqué Hernández for technical support in experimental design, Dr. Roberto Köferstein (Martin-Luther-Univeristät Halle-Wittenberg, Germany) for the XRD analysis. L.Q. acknowledges financial support by China Scholarship Council .
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12/5
Y1 - 2020/12/5
N2 - Perfluorooctanoic acid (PFOA) is of emerging concern owing to its global distribution and environmental persistence. Efficient degradation approaches are so far limited. Herein, we demonstrate for the first time the photochemical degradation of PFOA under UV-A irradiation after adsorption on Fe-doped zeolites with molecular oxygen as the terminal oxidant. In a system containing 1 g L−1 PFOA-loaded Fe-zeolites, outstanding PFOA decomposition (> 99 %) was achieved within 24 h under slightly acidic conditions (pH ≤ 5.5). Short-chain perfluorinated carboxylic acids (PFCAs) are the main intermediates, beside fluoride and CO2. No PFOA degradation occurs with Fe-free zeolites or dissolved ferric ions. Furthermore, we investigated the effects of pH, inorganic ions and gas atmospheres on PFOA degradation. A photochemical degradation mechanism with zeolite-bound iron species as catalytic sites for carboxylate-to-metal charge transfer is proposed. The presented study offers a novel approach for the removal of the highly recalcitrant PFOA from contaminated waters.
AB - Perfluorooctanoic acid (PFOA) is of emerging concern owing to its global distribution and environmental persistence. Efficient degradation approaches are so far limited. Herein, we demonstrate for the first time the photochemical degradation of PFOA under UV-A irradiation after adsorption on Fe-doped zeolites with molecular oxygen as the terminal oxidant. In a system containing 1 g L−1 PFOA-loaded Fe-zeolites, outstanding PFOA decomposition (> 99 %) was achieved within 24 h under slightly acidic conditions (pH ≤ 5.5). Short-chain perfluorinated carboxylic acids (PFCAs) are the main intermediates, beside fluoride and CO2. No PFOA degradation occurs with Fe-free zeolites or dissolved ferric ions. Furthermore, we investigated the effects of pH, inorganic ions and gas atmospheres on PFOA degradation. A photochemical degradation mechanism with zeolite-bound iron species as catalytic sites for carboxylate-to-metal charge transfer is proposed. The presented study offers a novel approach for the removal of the highly recalcitrant PFOA from contaminated waters.
KW - Degradation
KW - Fe-zeolites
KW - Heterogeneous photochemistry
KW - Perfluorooctanoic acid
KW - UV-A
UR - http://www.scopus.com/inward/record.url?scp=85087378199&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2020.119283
DO - 10.1016/j.apcatb.2020.119283
M3 - Article
AN - SCOPUS:85087378199
SN - 0926-3373
VL - 278
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 119283
ER -