PMID- 22827582
OWN - NLM
STAT- MEDLINE
DCOM- 20121217
LR  - 20131121
IS  - 1520-5851 (Electronic)
IS  - 0013-936X (Linking)
VI  - 46
IP  - 16
DP  - 2012 Aug 21
TI  - Iodine-sensitized degradation of 2,4,6-trichlorophenol under visible light.
PG  - 9005-11
LID - 10.1021/es301577p [doi]
AB  - Molecular iodine has been studied, for the first time, as a sensitizer for the 
      degradation of 2,4,6-trichlorophenol (TCP) in aqueous solution under visible 
      light (lambda >/= 450 nm). TCP was degraded in the presence of commercial I(2), but the 
      reaction rate decreased significantly after 2 h. When a solution of NaI and 
      H(2)O(2) was used as an iodine source with phosphotungstic acid (PW) as a 
      catalyst, TCP degradation was not only fast but also followed zero-order 
      kinetics. Importantly, the I(2) concentration remained unchanged with time, 
      indicative of I(2) recycling as a kind of photocatalyst. During TCP degradation, 
      2,6-dichloro-1,4-benzoquinone was produced as the main intermediate (76%), which 
      slowly degraded in the irradiated solution. For every equivalent of TCP consumed 
      at the 2 h time point, approximately 1.7 equivalents of chloride ions were 
      produced. Further study of the effect of variables including the type of 
      polyoxometalates (POM) and the initial concentration of each component revealed 
      that the rate of TCP degradation under visible light was determined by the rate 
      of I(2) production in the dark. The optimum pH and apparent activation energy for 
      TCP disappearance were 4.5 and 42.8 kJ/mol, respectively. It is proposed that TCP 
      degradation is initiated by iodine radicals produced from I(2) photolysis, 
      followed by I(2) regeneration through a POM-catalyzed oxidation of I(3)(-) by 
      H(2)O(2).
FAU - Hu, Meiqin
AU  - Hu M
AD  - Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
FAU - Wang, Yan
AU  - Wang Y
FAU - Xiong, Zhigang
AU  - Xiong Z
FAU - Bi, Dongqin
AU  - Bi D
FAU - Zhang, Yuhong
AU  - Zhang Y
FAU - Xu, Yiming
AU  - Xu Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120803
PL  - United States
TA  - Environ Sci Technol
JT  - Environmental science & technology
JID - 0213155
RN  - 0 (Chlorophenols)
RN  - 9679TC07X4 (Iodine)
RN  - MHS8C5BAUZ (2,4,6-trichlorophenol)
SB  - IM
MH  - Catalysis
MH  - Chlorophenols/*chemistry
MH  - Chromatography, High Pressure Liquid
MH  - Iodine/*chemistry
MH  - Kinetics
MH  - *Light
MH  - Spectrometry, Mass, Electrospray Ionization
MH  - Spectrophotometry, Ultraviolet
EDAT- 2012/07/26 06:00
MHDA- 2012/12/18 06:00
CRDT- 2012/07/26 06:00
PHST- 2012/07/26 06:00 [entrez]
PHST- 2012/07/26 06:00 [pubmed]
PHST- 2012/12/18 06:00 [medline]
AID - 10.1021/es301577p [doi]
PST - ppublish
SO  - Environ Sci Technol. 2012 Aug 21;46(16):9005-11. doi: 10.1021/es301577p. Epub 
      2012 Aug 3.