Photochemical decomposition of perfluorooctanoic acid in aqueous periodate with VUV and UV light irradiation.
The photochemical decomposition of perfluorooctanoic acid (PFOA) in aqueous periodate (IO(4)(-)) was investigated under two types of low-pressure mercury lamps: one emits at 254nm light (UV light) and the other emits both 254 nm and 185 nm light (VUV light). PFOA decomposed efficiently under VUV light irradiation while it decomposed poorly under UV light irradiation. The addition of IO(4)(-) significantly increased the rate of decomposition and defluorination of PFOA irradiated with UV light whereas it decreased both processes under VUV irradiation. Reactive radical (IO(3)) generated by photolysis of IO(4)(-) initiated the oxidation of PFOA in UV process. Aquated electrons (e(aq)(-)), generated from water homolysis, scavenged IO(4)(-) resulting in decrease of reactive radical species production and PFOA decomposition. The shorter-chain perfluorocarboxylic acids (PFCAs) formed in a stepwise manner from long-chain PFCAs.
Cao
M H
MH
Environmental Science Research Institution, College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Wang
B B
BB
Yu
H S
HS
Wang
L L
LL
Yuan
S H
SH
Chen
J
J
D002210:Caprylates / Q000737:chemistry* / Q000528:radiation effects*; D005461:Fluorine / Q000737:chemistry / Q000528:radiation effects; D005466:Fluorocarbons / Q000737:chemistry* / Q000528:radiation effects*; D005609:Free Radicals / Q000032:analysis; D007452:Iodates / Q000737:chemistry; D008027:Light; D010504:Periodic Acid / Q000737:chemistry*; D010777:Photochemistry; D010782:Photolysis; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D014867:Water
D002210:Caprylates; D005466:Fluorocarbons; D005609:Free Radicals; D007452:Iodates; D012996:Solutions; D014867:Water; D010504:Periodic Acid; D005461:Fluorine; C023036:perfluorooctanoic acid; C032285:sodium iodate