Reductive defluorination of perfluorooctanoic acid by titanium(III) citrate with vitamin B12 and copper nanoparticles

[Display omitted] •Reductive defluorination of PFOA using titanium(III) citrate with vitamin B12 and Cu0 was investigated.•The combination of B12 and Cu0 generate extraordinary reactive radicals for PFOA removal.•The performance of reductants for PFOA removal was titanium(III) citrate≫nano zero-vale...

Full description

Saved in:
Bibliographic Details
Published in:Journal of hazardous materials 2017-10, Vol.340, p.336-343
Main Authors: Lee, Yu-Chi, Chen, Yi-Pei, Chen, Meng-Jia, Kuo, Jeff, Lo, Shang-Lien
Format: Article
Language:English
Subjects:
Catalytic defluorination
Copper nanoparticles
Perfluorooctanoic acid
Reductive defluorination
Vitamin B12
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Reductive defluorination of PFOA using titanium(III) citrate with vitamin B12 and Cu0 was investigated.•The combination of B12 and Cu0 generate extraordinary reactive radicals for PFOA removal.•The performance of reductants for PFOA removal was titanium(III) citrate≫nano zero-valent Iron>NaBH4.•Mechanisms of PFOA hydrodefluorination through sequential electron transfer pathways were proposed. Perfluorooctanoic acid (PFOA) is widespread in the environment, which causes serious health and safety concerns. A mechanistic study on reductive defluorination of PFOA by titanium(III) citrate in the presence of catalysts was conducted. Vitamin B12 was used to catalyze reduction reactions by shuttling electrons from a reducing agent (electron donor) to PFOA to produce a Co-carbon bond intermediates. In the presence of copper nanoparticles, a precursor complex, B12-C7F14COOH, adsorbed on the metal surface, followed by a hydrogenolytic reaction to form less-fluorinated products. The synergistic effect between vitamin B12 and copper nanoparticles enhances the reductive activities by electron-transfer reactions and hydrogenolysis. The efficient reduction of PFOA to less-noxious compounds was demonstrated with a copper dose of 2gL−1, titanium(III) citrate (45mM), and vitamin B12 (0.2mM) with an initial pH of 9.0 and 70°C. In this anoxic aqueous solution, the biomimetic reductive system effectively removed 65% of PFOA. The mass balance on fluoride matched the observed degradation of PFOA, while no short-chain intermediates were detected.
ISSN:0304-3894
1873-3336
DOI:10.1016/j.jhazmat.2017.06.020