|
KMID : 1024520110200111499
|
|
Journal of the Environmental Sciences
2011 Volume.20 No. 11 p.1499 ~ p.1507
|
|
|
Chemical Treatment of the PCBs-laden Transformer Insulation Oil
|
|
Ryoo Keon-Sang
Choi Jong-Ha
Choi Jin-Whan
|
|
|
Abstract
|
|
|
Practical disposal of transformer insulation oil laden with PCBs (polychlorinated biphenyls) by a chemical treatment has been studied in field work. The transformer insulation oil containing PCBs was treated by the required amounts of PEG (polyethylene glycol) and KOH, along with different reaction conditions such as temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. Removal efficiencies of PCBs in insulation oil before and after chemical treatment were examined.
The removal efficiency of PCBs was very low at lower temperatures of 25 and 50 o C. Under the reaction condition of PEG 600/KOH/100 o C/2hr, removal efficiency of PCBs was approximately 70%, showing completely removal of PCBs containing 7～9 chlorines on biphenyl frame which appear later than PCB IUPAC Number 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to 150 o C and 4 hours, removal efficiency of PCBs reached 99.99% without any formation of PCDDS/PCDFs during the process. Such reaction conditions were verified by several official analytical institutions. In studying the reaction of PEG with PCBs, it confirmed that the process of chemical treatment led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.
|
|
|
KEYWORD
|
|
|
PCBs, Transformer insulation oil, PEG, Chemical treatment, Chlorine
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|