Avancerad sökning

Visar resultat 1 - 5 av 13 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Thermal formation and chlorination of dioxins and dioxin-like compounds

   Författare :Stina Jansson; Stellan Marklund; Mats Tysklind; Jochen F. Müller; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dioxin; dioxin-like compounds; isomer distribution pattern; homologue profile; injection; O2PLS; PCDD; PCDF; PCN; PCBz; PCPh; MSW combustion; formation; chlorination; flue gas; quench profiles; Environmental chemistry; Miljökemi;

   Sammanfattning : This thesis contributes to an increased understanding of the formation of dioxins and dioxin-like compounds in combustion processes. Although emissions to air from waste incineration facilities have been greatly reduced by the use of efficient air pollution control measures, the resulting residues (ashes and filters) are highly toxic and are classified as hazardous waste. LÄS MER

3. 2. Effects of Varying Combustion Conditions on PCDD/F Formation

   Författare :Johanna Aurell; Stellan Marklund; Sukh Sidhu; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dioxin; formation; PCDD; PCDF; MSW incineration; transient combustion; sulfur; memory effects; quench time; chlorine; combustion; polychlorinated dibenzothiophenes; NO; water; Environmental chemistry; Miljökemi;

   Sammanfattning : Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are by-products emitted from combustion sources such as municipal solid waste (MSW) incineration plants. These organic compounds are recognized as toxic, bioaccumulative and persistent in the environment. LÄS MER

4. 3. Formation and degradation of PCDD/F in waste incineration ashes

   Författare :Lisa Lundin; Stellan Marklund; Mats Tysklind; James Mulholland; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MSW; fly ash; remediation; ash; PCDD; PCDF; formation; degradation; destruction; dechlorination; thermal treatment; Environmental chemistry; Miljökemi;

   Sammanfattning : The disposal of combustible wastes by incineration is a controversial issue that is strongly debated by both scientists and environmental activists due to the resulting emissions of noxious compounds, including (inter alia) polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), heavy metals and acid gases like sulfur dioxide. Currently available air pollution control devices are capable of effectively cleaning flue gases, and PCDD/F emissions to air from modern municipal solid waste (MSW) incinerators are low. LÄS MER

5. 4. Fate and exposure assessment of PCDD/Fs at contaminated sites

   Författare :Annika Åberg; Karin Wiberg; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; contaminated sites; dioxins; PCDD F; exposure; food chain; modeling; risk assessment; physical-chemical properties; förorenade områden; dioxiner; PCDD F; exponering; födokedja; modellering; riskbedömning; fysikaliska-kemiska egenskaper; Environmental chemistry; Miljökemi;

   Sammanfattning : Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzo-furans (PCDFs) belong to the most toxic compounds known to science and they are defined as Persistent Organic Pollutants (POPs) under the Stock-holm Convention. The general human exposure to PCDD/Fs is primarily through dietary intake. LÄS MER

7. 5. Extraction of PCBs and PCDD/Fs from Food and Feed Matrices Using Pressurised Liquid Extraction (PLE)

   Författare :Sune Sporring; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytisk kemi; Analytical chemistry; Feed; Pressurised Liquid Extraction PLE ; Food; PCDD F; PCB;

   Sammanfattning : Since the Belgian dioxin crisis in 1999 there has been a great demand for fast, cheap and reliable methods to analyse food and feed samples. Traditional methods use large amounts of solvent for the extraction, are time demanding and laborious, but new and more sophisticated methods have been developed in recent years. LÄS MER