Document Detail


Dechlorination of polychlorinated biphenyls in transformer oil using UV and visible light.
MedLine Citation:
PMID:  23030392     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
A study on dechlorination of PCB138 in transformer oil (TO) and 2-propanol (IPA) using 254 nm ultraviolet (UV) light as well as dye sensitized visible light has been conducted. Studies on dechlorination of polychlorinated biphenyls (PCBs) in TO using visible light in the presence of methylene blue (MB) and triethylamine (TEA) (providing a 'photocatalytic' cycle) in both deaerated and aerated conditions have been conducted to determine effects of TO, MB and TEA on reaction rates. The results show that photolytic methods are effective in treating PCBs in TO, and that the oil plays a limited adverse role. Under UV irradiation, PCB 138 can be >99% dechlorinated in the presence 0.06% (w/w) TO in IPA within 1 h with a rate constant of 0.0853 min(-1), while 47% of PCB138 can be dechlorinated in 92.1% (w/w) TO in IPA within 2 h with a rate constant of 0.0051 min(-1). In the 'photocatalytic' system, 94% reduction of PCB 138 was achieved within 30 min with a rate constant of 0.0968 min(-1) when the solvent was 60.70% (w/w) TO in IPA, while 71% dechlorination of PCB138 was achieved within 30 min with a rate constant of 0.0382 min(-1) when 81.62% (w/w) TO was present. In treatment of 30-73 ppm PCBs in TO, the optimal concentration of MB and TEA were found to be 0.5 g/L and 58.08 g/L respectively. Because of quenching by oxygen, deaeration of the solution is necessary for an efficient reaction. The photocatalytic system is especially adapted for treating lower concentration of PCBs in TO.
Authors:
Jiansong Kong; Gopal Achari; Cooper H Langford
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering     Volume:  48     ISSN:  1532-4117     ISO Abbreviation:  J Environ Sci Health A Tox Hazard Subst Environ Eng     Publication Date:  2013  
Date Detail:
Created Date:  2012-10-03     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9812551     Medline TA:  J Environ Sci Health A Tox Hazard Subst Environ Eng     Country:  England    
Other Details:
Languages:  eng     Pagination:  92-8     Citation Subset:  IM    
Affiliation:
a Department of Civil Engineering , University of Calgary , Calgary , Canada.
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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