Complete removal of chlorinated aromatic compounds from oils by channel-type gamma-cyclodextrin assembly.
This paper describes the complete removal of chlorinated aromatic compounds from insulating oil by a channel-type gamma-cyclodextrin (gamma-CD) assembly as a new adsorbent. Using this type of adsorbent (50-60 wt % of oil), 1,2,4- and 1,3,5-trichlorobenzenes, 2- and 4-chlorobiphenyls (2- and 4-MCBs), 4,4'-dichlorobiphenyl (4,4'-DiCB), and 3,4,4'-trichlorobiphenyl (3,4,4'-TrCB), whose initial concentrations were 100 ppm, were completely removed from the insulating oil. Competitive adsorption experiments using a mixture of 2-MCB and 4-MCB or a mixture of 4-MCB, 4,4'-DiCB, and 3,4,4'-TrCB revealed that selective adsorption based on the shape and size of the chlorinated aromatics was achieved by the channel-type gamma-CD assembly, implying that inclusion into the cavity of the channel-type gamma-CD was responsible for the removal of chlorinated aromatics from insulating oil. It was also found that more than 70% of adsorbed chlorinated aromatics was easily recovered from the channel-type gamma-CD by simply washing with n-hexane, and chlorinated aromatics were completely removed from the insulating oil even by the regenerated adsorbent, indicating that the gamma-CD assembly can be easily regenerated and recycled.
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Toshiyuki
T
Kida
Takeshi
T
Nakano
Yoshinori
Y
Fujino
Chisato
C
Matsumura
Kazuhiro
K
Miyawaki
Eiichi
E
Kato
Mitsuru
M
Akashi
D000327:Adsorption; D002722:Chlorobenzenes / Q000302:isolation & purification; D006841:Hydrocarbons, Aromatic / Q000302:isolation & purification*; D006843:Hydrocarbons, Chlorinated / Q000302:isolation & purification*; D009821:Oils / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000302:isolation & purification; D047408:gamma-Cyclodextrins / Q000737:chemistry*
D002722:Chlorobenzenes; D006841:Hydrocarbons, Aromatic; D006843:Hydrocarbons, Chlorinated; D009821:Oils; D047408:gamma-Cyclodextrins; C036720:trichlorobenzene; D011078:Polychlorinated Biphenyls