Show simple item record

dc.creatorCajal Marinosa, Paula
dc.date.accessioned2011-10-24T09:19:19Z
dc.date.available2011-10-24T09:19:19Z
dc.date.issued2011-10-24
dc.identifier.urihttp://dspace.cc.tut.fi/dpub/handle/123456789/20702
dc.description.abstractPCBs are man-made organic compounds classified as persistent organic pollutants (POPs). They are characterised by their high applicability as cooling liquid, softener, surfactant, flame retardant, lubricator or dispergent. Such applicability leaded to a production of more than one million tones since the 1930s. They were mainly used in closed systems as dielectric fluids in transformers and capacitors, but also highly used in open applications as plasticizers in building materials. From this usage, release of PCB from the falling plaster of buildings, the flaking paint or the volatilisation of lower chlorinated congeners has been happening since the begins of 1980s, when the use of PCBs was banned. This project has focused on the degradation of PCBs directly over the surfaces in means of the advanced oxidation process known as Fenton. This technique is based on the capability of H2O2 for creating hydroxyl radicals when catalyzed with iron. The final aim is to treat real surfaces in order to decrease the PCB concentration to acceptable level. Also might be suitable for treating contaminated surfaces affected by condensator fires or explosions. Two different surfaces have been used in order to simulate the real conditions. These surfaces have been glass and brick. They both have been artificially contaminated with a commercial mixture of PCBs known as Aroclor 1260, which was typically used in paints and sealants. The concentrations used are found among the real ones detected in several causes in Finland. Subsequently, the surfaces were treated with the Fenton reagents. Then, an extraction of the PCBs has been made in order to analyse them with GC-MS. The effects of the ratio of H2O2 and Aroclor 1260, the time of reaction, the way of adding the reagents and the degree of chlorination of the PCB congeners, are the main subjects involved in this study. Also two ways of extracting the PCBs from the surfaces, one with a solution of hexane/acetone and other with wiped cotton, have been compared. Results show a reduction around 70% in both surfaces, but lower weight ratio Fe2+/H2O2/Aroclor is needed in the glass (204:250:1) than in the brick surface (136:500:1). It seems that more than seven days are needed for maximal degradation. Degradation occurs in a higher grade on the low chlorinated congeners. Also it has been found that the extraction of PCBs with cotton wiped in alcohol does not seem to be very repeatable when compared with the extraction by hexane-acetone solution. /Kir11
dc.format.mimetypeapplication/pdf
dc.language.isoenen
dc.relation.isformatof64 p.en
dc.rightsThis publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.en
dc.titleFenton Treatment of PCB-contaminated Surfacesen
dc.typeDiplomityö
dc.identifier.urnURN:NBN:fi:tty-2011102414851
dc.thsTuhkanen, Tuula
dc.contributor.laitosBio- ja ympäristötekniikan laitos – Institute of Environmental Engineering and Biotechnologyen
dc.contributor.tiedekuntaYmpäristötekniikan osasto – Department of Environmental Technology
dc.contributor.yliopistoTampereen teknillinen yliopisto - Tampere University of Technologyfi
dc.date.published2007-06-06
dc.contributor.laitoskoodibio


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record