Photodegradation of bisphenol Z by UV irradiation in the presence of beta-cyclodextrin.
In this work, the formation of the inclusion complex of bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane, abbreviated as BPCH) with beta-cyclodextrin (beta-CD) has been studied, 1:1 inclusion complex can be obtained, the formation constant of the beta-CD/BPCH complex is 5.94x10(3)M(-1). The photodegradation behavior of BPCH was investigated under monochromatic UV irradiation (lambda=254 nm). The photodegradation rate constant of BPCH in aqueous solutions with beta-CD showed a 9.0-fold increase, and simultaneously the mineralization of BPCH can be enhanced by beta-CD. The influence factors on photodegradation of BPCH were also studied and described in details, such as concentration of beta-CD, initial concentration of BPCH, organic solvent and pH. The photodegradation of BPCH in the presence of beta-CD includes the direct photolysis and the photooxidation of BPCH during the photochemical process. Some predominant photodegradation products are 4-(2,4,5-trihydroxy-phenyl)-4-(4-hydroxyphenyl) butanoic acid, 5,5-bis(4-hydroxyphenyl)pentanoic acid, meta-hydroxylated BPCH, ortho-hydroxylated BPCH and 4-(1-(4-hydroxyphenyl)pentyl)phenol respectively. The enhancement of photodegradation of BPCH mainly results from moderate inclusion depth of BPCH molecule in the beta-CD cavity. This kind of inclusion structure allows BPCH molecule sufficient proximity to secondary hydroxyl groups of the beta-CD cavity, and these hydroxyl groups could be activated and converted to hydroxyl radicals under UV irradiation, which can enhance the photooxidation of BPCH.
Wang
Guanghui
G
School of Resources and Environmental Science, Wuhan University, Wuhan 430079, PR China.
Qi
Purong
P
Xue
Xiaofei
X
Wu
Feng
F
Deng
Nansheng
N
D000097:Acetonitriles; D001559:Benzhydryl Compounds; D002853:Chromatography, Liquid; D003510:Cyclohexanes / Q000737:chemistry* / Q000528:radiation effects*; D052244:Endocrine Disruptors / Q000737:chemistry* / Q000528:radiation effects*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013058:Mass Spectrometry; D010782:Photolysis; D012997:Solvents; D013050:Spectrometry, Fluorescence; D014466:Ultraviolet Rays; D047392:beta-Cyclodextrins / Q000737:chemistry*; D000098704:Bisphenols
D000097:Acetonitriles; D001559:Benzhydryl Compounds; D003510:Cyclohexanes; D052244:Endocrine Disruptors; D012997:Solvents; D047392:beta-Cyclodextrins; C517113:bisphenol Z; D000098704:Bisphenols; C031215:betadex; C032159:acetonitrile