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1
Yang, Yun. "Temperature dependent PCDD/PCDF product distributions from phenols". Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/20182.
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Moore, Paul 1962. "The Analysis of PCDD and PCDF Emissions from the Cofiring of Densified Refuse Derived Fuel and Coal". Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc330690/.
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The United States leads the world in per capita production of Municipal Solid Waste (MSW), generating approximately 200 million tons per year. By 2000 A.D. the US EPA predicts a 20% rise in these numbers. Currently the major strategies of MSW disposal are (i) landfill and (ii) incineration. The amount of landfill space in the US is on a rapid decline. There are -10,000 landfill sites in the country, of which only 65-70% are still in use. The Office of Technology Assessment (OTA) predicts an 80% landfill closure rate in the next 20 years. The development of a viable energy resource from MSW, in the form of densified Refuse Derived Fuel (dRDF), provides solutions to the problems of MSW generation and fossil fuel depletions. Every 2 tons of MSW yields approximately 1 ton of dRDF. Each ton of dRDF has an energy equivalent of more than two barrels of oil. At current production rates the US is "throwing away" over 200,000,000 barrels of oil a year. In order to be considered a truly viable product dRDF must be extensively studied; in terms of it's cost of production, it's combustion properties, and it's potential for environmental pollution. In 1987 a research team from the University of North Texas, in conjunction with the US DOE and Argonne National Laboratory (ANL), cofired over 550 tons of dRDF and bdRDF with a high sulfur Kentucky coal in a boiler at ANL. This work examines the emission rates of polychlorinated dioxins (PCDDs) and furans (PCDFs) during the combustion of the dRDF, bdRDF, and coal. Even at levels of 50% by Btu content of dRDF in the fuel feedstock, emission rates of PCDDs and PCDFs were below detection limits. The dRDF is shown to be an environmentally acceptable product, which could help resolve one of the major social and environmental problems facing this country today.
3
Weber, P. [Verfasser]. "Der Chlortransfer bei der Bildung von polychlorierten organischen Spurenstoffen (PCDD/PCDF) in industriellen thermischen Prozessen (Müllverbrennung) / P. Weber". Karlsruhe : KIT-Bibliothek, 2000. http://d-nb.info/1198219823/34.
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4
Lundin, Lisa. "Formation and degradation of PCDD/F in waste incineration ashes". Doctoral thesis, Umeå : Department of Chemistry, Umeå University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1395.
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Frýba, Lukáš. "Analýza alternativ odstraňování PCDD/F při spalování odpadů". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229471.
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The thesis is focused on analyzing the current status of the technology used for cleaning flue gas from persistent organic pollutants, especially PCDD/F. For the three most commonly used methods of solution operational and energy efficiency comparison was made, where achievable energy export and the impact of the change in working conditions on the efficiency indicators of energy production and use of the energy was evaluated. In conditions we considered an alternative machine-technological solutions used for the final disposal of persistent organic pollutants resulting from the waste combustion in terms of additional operating costs and energy efficiency.
6
Aurell, Johanna. "Effects of Varying Combustion Conditions on PCDD/F Formation". Doctoral thesis, Umeå universitet, Kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1795.
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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. PCDD/Fs are removed from flue gases before released from MSW incineration. However, the PCDD/Fs are not destroyed but retained in the residues, thus in the environment. Understanding the pathways that lead to their formation is important in order to develop ways to suppress their formation and prevent their release into the environment. Suppressing the formation can also allow less expensive air pollution control system to be used, and/or the costs of thermally treating the residues to be reduced. The main objective of the studies underlying this thesis was to elucidate process, combustion and fuel parameters that substantially affect the emission levels and formation of PCDD/Fs in flue gases from MSW incineration. The experiments were conducted under controllable, realistic combustion conditions using a laboratory-scale reactor combusting artificial MSW. The parameter found to most strongly reduce the PCDD/F emissions, was prolonging the flue gas residence time at a relatively high temperature (460°C). Increasing the sulfur dioxide (SO2) to hydrogen chloride (HCl) ratio to 1.6 in the flue gas was also found to reduce the PCDF levels, but not the PCDD levels. Fluctuations in the combustion process (carbon monoxide peaks), high chlorine levels in the waste (1.7%) and low temperatures in the secondary combustion zone (660°C) all tended to increase the emission levels. The PCDD/PCDF ratio in the flue gas was found to depend on the chlorine level in the waste, fluctuations in the combustion process and the SO2:HCl ratio in the flue gas. The formation pathways were found to be affected by the quench time profiles in the post-combustion zone, fluctuations in the combustion process and addition of sulfur. In addition, increased levels of chlorine in the waste increased the chlorination degrees of both PCDDs and PCDFs. A tendency for increased SO2 levels in the flue gas to increase levels of polychlorinated dibenzothiophenes (sulfur analogues of PCDFs) was also detected, however the increases were much less significant than the reduction in PCDF levels.
7
Åberg, Annika. "Fate and exposure assessment of PCDD/Fs at contaminated sites". Licentiate thesis, Umeå University, Chemistry, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-5717.
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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. The importance of contaminated sites as secondary PCDD/F sources (i.e. sources that once received its contamination from a primary source) are getting increased attention. To be able to assess the risks for human exposure at PCDD/F contaminated sites, the environmen-tal distribution of PCDD/Fs and the potential mobilization between dif-ferent environmental media (e.g. food chain transfer) must be known. The primary aim of the work presented in this thesis was to investigate human exposure pathways associated with PCDD/F contaminated sites by combining field measurements and modeling. Site specific field measurements were made at a PCDD/F contaminated site in Sweden and multimedia modeling scenarios were evaluated against site specific data and national reference data.
The results show that the congener distributions in exposure media affected by contaminated soil may differ significantly from the distribu-tions found in media from reference locations. Higher chlorinated PCDD/Fs may be transferred into food chains where they contribute to a large fraction of the toxic equivalent concentration (TEQ). Ingestion of locally produced animal food may be an important exposure pathway al-ready at low or moderate PCDD/F soil concentrations. However, the con-gener composition of the source is critical for the exposure. The signifi-cance of the individual exposure routes varies depending on e.g. the spatial distribution and magnitude of the soil contamination, the pro-perties of the exposure media and the human behavior. Multimedia mo-deling can be used in risk assessments as long as model algorithms and model parameters are representative for the superhydrophobic properties of PCDD/Fs. However, selection of physical-chemical PCDD/F properties is a challenge due to large variation in reported values. For some proper-ties, data is scattered or completely lacking
8
Stark, Marie Luise [Verfasser]. "Transfer von Dioxinen (PCDD), Furanen (PCDF) und polychlorierten Biphenylen (PCB) aus dem Futter in ausgewählte Gewebe wachsender Schafe / Marie Luise Stark". Berlin : Freie Universität Berlin, 2021. http://nbn-resolving.de/urn:nbn:de:kobv:188-refubium-31051-8.
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Liljeroos, Tom. "Är saltglaseringsindustrin en källa till tidig organokloridförekomst?" Thesis, Halmstad University, School of Teacher Education (LUT), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-2365.
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Abstract.
The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc.
Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed.
Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that. Some sources date the origin of the technique to the 13'Th century. Salt glazed ceramics were the prime type of industrial vessels and it was extensively used for food preservation in households from the 17'Th century to the early/mid 20'Th century.
The method was/is primarily used by Germany, Great Britain, America and Sweden.
Salt glazing is a source of graphite structures from soot, and of chlorine gas. Hence, the formation of organochlorides should be able to occur.
The reports main objective is to highlight the question; “Could the salt glazing industry be one of the sources to early dioxin emissions?” Secondary objectives are to present an introduction to dioxin and comparable substances, methods of analysis and symptoms of exposure.
The salt glazing industry is much likely one of the anthropogenic sources of early PCDD/F emissions. Though emission levels seem to be quite low, due to the persistence of PCDD/F noticeable levels could have accumulated. When the Leblanc soda process (a known source of PCDD/F) was introduced in 1791, the salt glazing process had already been used for nearly three hundred years.
10
Sewart, Andrew Paul. "The fate and behaviour of polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls in sewage sludge : amended agricultural soils and their potential transfer into terrestrial foodchain via lactating cattle". Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261004.
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Quinn, Laura Penelope. "Persistent organic pollutants (POPs) in soil associated with an active incinerator in Potchefstroom, South Africa / L.P. Quinn". Thesis, North-West University, 2005. http://hdl.handle.net/10394/1013.
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POPs are a group of chemicals that have been extensively studied over the last few
years. The main reason that these chemicals have received so much scientific
attention is the myriad of negative effects they have on the environment and human
health. The properties that cause the deleterious effects include a high molecular
stability, rendering them highly persistent. Added to this is the lipophilic and
hydrophobic nature of the compounds. POPs will thus tend to bio-accumulate and
bio-magnify in the environment, causing a direct threat to humans and wildlife. To
address this threat, the Stockholm Convention on Persistent Organic Pollutants,
under the supervision of United Nations Environment programme (UNEP), was
initiated and became legally binding on 17 May 2004. All countries, including South
Africa, which ratified this agreement, will be expected to monitor and regulate the
formation of POPs.
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs)
and polychlorinated biphenyls (PCBs) are all members of the dioxin-like family of
POPs. This family of chemicals pose serious health threats such as carcinogenic
effects and negative effects on reproduction. These substances, with the exception of
PCBs, are formed unintentionally as by-products of industrial and thermal processes.
One of the main sources of dioxin-like chemicals is medical waste incinerators.
In this project the area surrounding a medical waste incinerator was monitored using
a bio-assay technique. The determination of dioxin concentrations is usually
preformed by chemical analysis, however, bio-assays have proven themselves to be
a cheaper and time-saving screening method. The Toxic Equivalency Quotient
(TEQs) determined through bio-assays can support chemical analysis in determining
biologically-relevant risk assessments since bio-assay data has ecotoxicological
relevance. These assays represent an integrated biological response to chemical
pollutants, where biological effects are accounted for which is not possible in
chemical analyses. One of the bio-assays used in the determination of the dioxin-like
chemical TEQ is the H411 E reporter gene bio-assay. This assay is based on the Ah-receptor
mediated toxicity of dioxin-like chemicals. Using this technique the TEQs for
areas surrounding an active incinerator were determined, to indicate the distribution
of these substances. The TEQs for the soil samples collected ranged between nondetectable
and 154 ngTEQ/kg. There was no clear distributional pattern and the total
organic carbon content in the soil did not seem to play a crucial role in the distribution
of dioxin-like chemicals. Although a decrease in soil tillage showed a corresponding
increase in TEQ. The predominant wind direction was taken into account but no
correlation could be seen. However, meteorological parameters such as the ambient
temperature and low precipitation in the area may have contributed to lower TEQ
values. Cytotoxicity excluded data points and the phenomenon has to be addressed.
High TEQ values in a residential area where free-range chickens are raised pose a
serious concern to the level of dietary dioxin-like chemical intake. Eggs in the area
could theoretically contain between 2.75 and 28.75 pgTEQ/g egg fat. Further studies
are needed to determine how much dioxin-like chemicals are being transferred to
humans through the consumption of free-range eggsThesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
12
Gaus, Caroline, i n/a. "Dioxins in the Marine Environment: Sources, Pathways and Fate of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Queensland, Australia". Griffith University. School of Public Health, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030624.144111.
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Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans(PCDFs) are two groups of lipophilic, persistent organic pollutants that are produced as by-products of various anthropogenic and industrial processes. Due to their relatively high toxic potencies and potential to bioaccumulate and biomagnify in organisms and through the food chain, the contemporary widespread distribution of these compounds is a concern to the health of the environment, wildlife and humans. This study determined the distribution, pathways and fate of PCDD/Fs in the coastal zone of Queensland, Australia, including the inshore marine environment of the World Heritage Great Barrier Reef Marine Park. This ecosystem supports unique fauna and flora such as the marine herbivorous mammal dugong (Dugong dugon) and its food source, seagrass. Elevated PCDD/Fs were present in soils and sediments along the entire Queensland coastline. Highest concentrations were found in soil from agricultural irrigation drains and in sediments near the mouths of major rivers. Elevated concentrations were associated with rural and urban types of land-use, and PCDD/Fs were present even in locations remote from anthropogenic activities. PCDD/F congener-specific analysis revealed an unusual profile in all samples, dominated by OCDD, with PCDFs present in low concentrations or below the limit of detection. Distinct HxCDD isomer patterns were observed, with the 1,2,3,7,8,9-HxCDD/1,2,3,4,6,7-HxCDD isomer pair dominating the 2,3,7,8-substituted HxCDDs. Similar congener and isomer characteristics were reported in sediments, soil and clay samples from other continents, but could not be attributed to any known source. Possible PCDD/F sources in Queensland were assessed using segmented estuarine sediment cores, for which radiochemical chronologies were established for each depth. Variations of PCDD/F concentrations in the sediment cores over several centuries of depositional history were relatively small. Elevated PCDD levels were still present in sediment slices from the early 17th century. PCDD/F homologue profiles in sediments deposited during the last 350 years were almost identical and correlated well to the characteristic profiles observed in surface sediments and soils from the entire Queensland coastline. These results suggested the presence of an unidentified PCDD source prior to the production of commercial organochlorine products. To investigate the formation of the unusual PCDD/F profiles, congener and isomer specific analyses were undertaken in soils, sediments and dated sediment cores. The results demonstrated that specific transformation processes in the environment have resulted in the observed PCDD profile characteristics. Dechlorination of OCDD was proposed to result in distinct 1,4-pattern characteristics (i.e. formation of isomers chlorinated in the 1,4,6,9-positions). Consequently, the environmental samples do not reflect the signatures of the original source. An alternative hypothesis to natural formation is discussed evaluating these processes and their implications for possible source contributions. This hypothesis explores the potential for the influence of anthropogenic PCDD precursors (e.g. pentachlorophenol) during the 1940s to 1990s. Transport of PCDD/Fs from the land-based source via impacted tributary river systems, and subsequent deposition processes are proposed to result in PCDD/F accumulation in the inshore marine ecosystem. The extent of the sediment PCDD/F contamination governs the concentrations in the extensive inshore marine seagrass meadows of Queensland. Partitioning processes in the sediment-seagrass system lead to increased toxic equivalency (TEQ) in the seagrass, compared to sediment.The relationship between contaminated inshore sediments, seagrass and dugongs were evaluated using six dugong habitat regions along the coastline. PCDD/F body burdens in dugongs are governed by sediment (and seagrass) PCDD/F concentrations in their habitat. High seagrass (and incidental sediment) ingestion rates, selective retention of toxicologically potent congeners and relatively low PCDD/F elimination capacities in dugongs are proposed to result in elevated PCDD/F concentrations and TEQ levels in adult animals. Transfer efficiencies of 4 and 27% of maternal TEQ levels to foetuses and calves (respectively) during gestation and lactation result in relatively high exposure potentials to offspring. Compared to no-observed-adverse-effect-levels in other mammals, and based on the results of this study, a tolerable daily intake (TDI) of 10-24 pg TEQ kg-1 day-1 was estimated for dugongs. The results of the present study found that dugongs from some regions along the coastline of Queensland exceed this TDI by up to 20 fold, suggesting that these populations may be at risk from PCDD/F contamination in their habitat. These results have important implications for the health of the environment, wildlife and humans and were used to develop a conceptual understanding of the sources, pathways and fate of dioxins in Queensland, Australia.
13
Gaus, Caroline. "Dioxins in the Marine Environment: Sources, Pathways and Fate of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Queensland, Australia". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367537.
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Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans(PCDFs) are two groups of lipophilic, persistent organic pollutants that are produced as by-products of various anthropogenic and industrial processes. Due to their relatively high toxic potencies and potential to bioaccumulate and biomagnify in organisms and through the food chain, the contemporary widespread distribution of these compounds is a concern to the health of the environment, wildlife and humans. This study determined the distribution, pathways and fate of PCDD/Fs in the coastal zone of Queensland, Australia, including the inshore marine environment of the World Heritage Great Barrier Reef Marine Park. This ecosystem supports unique fauna and flora such as the marine herbivorous mammal dugong (Dugong dugon) and its food source, seagrass. Elevated PCDD/Fs were present in soils and sediments along the entire Queensland coastline. Highest concentrations were found in soil from agricultural irrigation drains and in sediments near the mouths of major rivers. Elevated concentrations were associated with rural and urban types of land-use, and PCDD/Fs were present even in locations remote from anthropogenic activities. PCDD/F congener-specific analysis revealed an unusual profile in all samples, dominated by OCDD, with PCDFs present in low concentrations or below the limit of detection. Distinct HxCDD isomer patterns were observed, with the 1,2,3,7,8,9-HxCDD/1,2,3,4,6,7-HxCDD isomer pair dominating the 2,3,7,8-substituted HxCDDs. Similar congener and isomer characteristics were reported in sediments, soil and clay samples from other continents, but could not be attributed to any known source. Possible PCDD/F sources in Queensland were assessed using segmented estuarine sediment cores, for which radiochemical chronologies were established for each depth. Variations of PCDD/F concentrations in the sediment cores over several centuries of depositional history were relatively small. Elevated PCDD levels were still present in sediment slices from the early 17th century. PCDD/F homologue profiles in sediments deposited during the last 350 years were almost identical and correlated well to the characteristic profiles observed in surface sediments and soils from the entire Queensland coastline. These results suggested the presence of an unidentified PCDD source prior to the production of commercial organochlorine products. To investigate the formation of the unusual PCDD/F profiles, congener and isomer specific analyses were undertaken in soils, sediments and dated sediment cores. The results demonstrated that specific transformation processes in the environment have resulted in the observed PCDD profile characteristics. Dechlorination of OCDD was proposed to result in distinct 1,4-pattern characteristics (i.e. formation of isomers
chlorinated in the 1,4,6,9-positions). Consequently, the environmental samples do not reflect the signatures of the original source. An alternative hypothesis to natural formation is discussed evaluating these processes and their implications for possible source contributions. This hypothesis explores the potential for the influence of anthropogenic PCDD precursors (e.g. pentachlorophenol) during the 1940s to 1990s. Transport of PCDD/Fs from the land-based source via impacted tributary river systems, and subsequent deposition processes are proposed to result in PCDD/F accumulation in the inshore marine ecosystem. The extent of the sediment PCDD/F contamination governs the concentrations in the extensive inshore marine seagrass meadows of Queensland. Partitioning processes in the sediment-seagrass system lead to increased toxic equivalency (TEQ) in the seagrass, compared to sediment.The relationship between contaminated inshore sediments, seagrass and dugongs were evaluated using six dugong habitat regions along the coastline. PCDD/F body burdens in dugongs are governed by sediment (and seagrass) PCDD/F concentrations in their habitat. High seagrass (and incidental sediment) ingestion rates, selective retention of toxicologically potent congeners and relatively low PCDD/F elimination capacities in dugongs are proposed to result in elevated PCDD/F concentrations and TEQ levels in adult animals. Transfer efficiencies of 4 and 27% of maternal TEQ levels to foetuses and calves (respectively) during gestation and lactation result in relatively high exposure potentials to offspring. Compared to no-observed-adverse-effect-levels in other mammals, and based on the results of this study, a tolerable daily intake (TDI) of 10-24 pg TEQ kg-1 day-1 was estimated for dugongs. The results of the present study found that dugongs from some regions along the coastline of Queensland exceed this TDI by up to 20 fold, suggesting that these populations may be at risk from PCDD/F contamination in their habitat. These results have important implications for the health of the environment, wildlife and humans and were used to develop a conceptual understanding of the sources, pathways and fate of dioxins in Queensland, Australia.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Public Health
Faculty of Health Sciences
Full Text
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Fàbrega, Bonadona Francesc. "Physiologically-Based Pharmacokinetic (Pbpk) Modeling of Pcdd/Fs and Pfass in Humans". Doctoral thesis, Universitat Rovira i Virgili, 2014. http://hdl.handle.net/10803/284035.
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Els models farmacocinètics (PBPK) són representacions matemàtiques del cos humà, que tenen com a objectiu calcular la concentració de compostos químics en els teixits humans. Els models PBPK poden millorar el càlcul del risc per a la salut humana, però de moment no han estat escassament utilitzats. Entre els compostos ambientals més perillosos per a la salut humana destaquen les dibenzo-p-dioxines policlorades i dibenzofurans policlorats (PCDD/Fs) i els compostos perfluorats (PFASs).
L’objectiu de la present tesis es el desenvolupament de un model PBPK per calcular la concentració de PCDD/Fs i PFASs en teixits humans.
Prèviament al desenvolupament del model PBPK, es va desenvolupar un índex de risc utilitzant mapes auto-organitzats (SOM), per calcular els compostos ambientals més perillosos per a la salut humana. Entre els compostos més perillosos es van trobar els PFASs. Després es va desenvolupar el model PBPK per predir les concentracions de PCDD/Fs en sang i en teixit adipós. Els resultats finals van ser altament coincidents amb els resultats experimentals trobats a l’àrea de Tarragona (NE d’Espanya), y per això es va considerar el model com a validat. A continuació el model es va adaptar per calcular les concentracions de PFASs. Per això, primer es va adaptar el model per PFOS i PFOA, que són els compostos perfluorats més estudiats en la literatura, i després es va estendre el model a 9 PFASs més. Finalment, es va fer un anàlisis de la incertesa del model PBPK, i la incertesa paramètrica es va estudiar visual i estadísticament.Los modelos farmacocinéticos (PBPK) son representaciones matemáticas del cuerpo humano, que tienen como objetivo calcular la concentración de químicos en los tejidos humanos. Los modelos PBPK pueden mejorar el cálculo de riesgo para la salud humana, pero hasta el momento no han sido muy usados. Entre los compuestos ambientales más peligrosos para la salud humana destacan las dibenzo-p-dioxinas policloradas y los dibenzofuranos policlorados (PCDD/Fs) y los compuestos perfluorados (PFASs). El objetivo de la presente tesis es el desarrollo un modelo PBPK para calcular la concentración de PCDD/Fs y PFASs en tejidos humanos. Previo al desarrollo del modelo PBPK se desarrolló un índice de riesgo usando mapas auto-organizados (SOM), para calcular los compuestos ambientales más peligrosos para la salud humana. Los PFASs se encontraron entre los compuestos de más riesgo. Después se desarrolló el modelo PBPK para predecir las concentraciones de PCDD/Fs en sangre y en tejido adiposo. Los resultados finales fueron muy coincidentes con los resultados experimentales encontrados en el área de Tarragona (NE de España), y por esta razón el modelo se consideró como validado. A continuación el modelo se adaptó para calcular las concentraciones de PFASs. Para ello, primero se adaptó el modelo para PFOS y PFOA, que son los compuestos perfluorados más estudiados en la literatura, y después se extendió el modelo a otros 9 PFASs. Finalmente, se hizo un análisis de la incertidumbre del modelo PBPK, y la incertidumbre paramétrica se estudio visual y estadísticamente.
Physiologically based pharmacokinetic (PBPK) models are mathematic representations of the human body that aims to assess the time course distribution of chemicals in human tissues. PBPK models may improve the assessment of human health risk but until now were not well studied. Among the most harmful environmental pollutants for human health there are polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and perfluoroalkyl substances (PFASs). The objective of the present work is to develop a PBPK model to assess the time course concentration of PCDD/Fs and PFASs in human tissues. Previously to the PBPK model development, a ranking index was developed using self-organizing maps (SOM) to assess the most harmful environmental contaminants, being PFASs among the most harmful compounds. After that, the PBPK model was developed to assess and predict the concentration of PCDD/Fs in human blood and adipose tissue. The final outcomes were very coincident with the experimental data found in Tarragona County (NE of Spain), and the model was considered as a validated. After that, the model was adapted to assess the concentrations of PFASs. Firstly the model was developed for PFOS and PFOA, that are the most studied compounds in the research literature, and then the model was expended to 9 PFASs more. Finally the uncertainty analysis of the PBPK model was conducted, and the parametric uncertainty was visually and statistically studied.
15
Cornea, Flavia. "Evaluation of an alternative extraction method of PCDD/Fs from flue gas samples". Thesis, Umeå universitet, Kemiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-124550.
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Gao, Qiuju. "Dioxins and dioxin-like compounds in thermochemical conversion of biomass : formation, distribution and fingerprints". Doctoral thesis, Umeå universitet, Kemiska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-118861.
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In the transition to a sustainable energy supply there is an increasing need to use biomass for replacement of fossil fuel. A key challenge is to utilize biomass conversion technologies in an environmentally sound manner. Important aspects are to minimize potential formation of persistent organic pollutants (POPs) such as dioxins and dioxin-like compounds. This thesis involves studies of formation characteristics of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and naphthalenes (PCNs) in microwave-assisted pyrolysis (MAP) and torrefaction using biomass as feedstock. The research focuses are on their levels, distributions, fingerprints (homologue profiles and isomer patterns) and the underlying formation pathways. The study also included efforts to optimize methods for extracting chlorinated aromatic compounds from thermally treated biomass. The overall objective was to contribute better understanding on the formation of dioxins and dioxin-like compounds in low temperature thermal processes. The main findings include the following: Pressurized liquid extraction (PLE) is applicable for simultaneous extraction of PCDDs, PCDFs, PCNs, polychlorinated phenols and benzenes from thermally treated wood. The choice of solvent for PLE is critical, and the extraction efficiency depends on the degrees of biomass carbonization. In MAP experiments PCDDs, PCDFs and PCNs were predominantly found in pyrolysis oils, while in torrefaction experiments they were mainly retained in solid chars with minor fractions in volatiles. In both cases, highly chlorinated congeners with low volatility tended to retain on particles whereas the less chlorinated congeners tended to volatize into the gas phase. Isomer patterns of PCDDs, PCDFs and PCNs generated in MAP were more selective than those reported in combustion processes. The presence of isomers with low thermodynamic stability suggests that the pathway of POPs formation in MAP may be governed not only by thermodynamic stabilities but also by kinetic factors. Formation of PCDDs, PCDFs and PCNs depends not only on the chlorine contents in biomass but also the presence of metal catalysts and organic/metal-based preservatives. Overall, the results provide information on the formation characteristics of PCDDs, PCDFs and PCNs in MAP and torrefaction. The obtained knowledge is useful regarding management and utilization of thermally treated biomass with minimum environmental impact.
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Al, Mamoon Hassan. "Evaluation of the separation capacity of different GC columns for tetra- to octachlorinated PCDD/Fs". Thesis, Umeå universitet, Kemiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-68387.
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Rey, Martínez María Dolores. "Formación de PCDD/Fs y otros contaminantes en procesos térmicos: aprovechamiento de biomasa y motores de combustión interna". Doctoral thesis, Universidad de Alicante, 2014. http://hdl.handle.net/10045/41125.
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Sircar, Robin. "Untersuchung der Emissionen aus Einäscherungsanlagen und der Einsatzmöglichkeiten von Barrierenentladungen zur Verringerung des PCDD/F-Austrages". [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965442683.
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Swiegelaar, Caitlin Reneé. "The effect of different sample preparatory protocols on the induction of the aryl hydrocarbon receptor (AhR) in the H4IIE-luc reporter gene bio-assay / Caitlin Reneé Swiegelaar". Thesis, North-West University, 2012. http://hdl.handle.net/10394/9702.
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Concern on a global scale gave rise to the founding of the Stockholm Convention on persistent organic pollutants (POPs) with a view to restrict the use and production of these toxic chemicals. As a signatory, South Africa is legally bound to abide to the Convention’s objectives, including participating in relevant research and monitoring. However, developing countries such as South Africa have limited information concerning POPs, partially because these countries do not have sufficient analytical capabilities, and thus method development and refinement are necessary. One group of POPs consisting of polychlorinated dibenzo-pdioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs), collectively referred to as dioxins, are of particular concern due to their high toxicity and persistence. Additionally, the analysis of dioxins is recognised as one of the most analytically challenging of its kind. This study investigated the effect of different preparatory protocols on the semi-quantification of dioxins using the H4IIE-luc-reporter gene assay. The protocols evaluated were either Soxhlet or pressurised liquid extraction (PLE) combined with a manual acid digestion, gel permeation chromatography (GPC) and Florisil fractionation clean-up procedure as well as the automated Total Rapid Prep™(TRP) system which makes use of a PLE combined with a multi-layer silica, alumina and carbon column clean-up procedure. To evaluate the protocols, an eight point matrix matched calibration curve, two soil samples and a certified reference material (CRM) were used. The extracts were semi-quantified by the H4IIE-luc bio-assay. During the course of the assay, the appropriateness of different standards was investigated, and a mixed standard containing all 17 toxic PCDD/Fs was chosen for quantification. During the data review process, higher bioassay equivalent (BEQ) values were obtained from PLE compared to Soxhlet extraction, while no statistically significant difference (Kruskal-Wallis ANOVA: p > 0.05) was found between the assay quantifications for the different preparatory techniques. However, the results of the H4IIE bio-assay were larger than the expected values. The identity of the chemicals that were in all likelihood responsible for the higher response was investigated through instrumental analysis using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GCxGC-TOFMS). Instrumental results indicated a high level of PAHs in the extracts, which could lead to super induction of the aryl hydrocarbon receptor (AhR) and therefore, to a positive bias in the results. Instrumental screening proved that all selected preparatory protocols were inadequate at removing interfering compounds and not sufficiently selective for PCDD/Fs, although the TRP was more successful in removing interferences. The high matrix interference hindered peak identification. Additionally, as indicated by instrumental analysis, the weak recovery of PCDD/Fs could be ascribed to high evaporation temperatures. The effect of different reference standards in the H4IIE bio-assay used during semi-quantification needs further investigation; similarly, the optimisation of extraction, evaporation and clean-up protocols and the use of different GCxGC-TOFMS column combinations aimed at more efficient separation needs to be investigated.
The assistance of the National Metrology Institute (funded through the Department of Trade and Industry) towards this research is hereby acknowledged.Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2013.
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Weidemann, Eva. "Waste incineration residues : Persistent organic pollutants in flue gas and fly ash from waste incineration". Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-92765.
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Modern societies produce large quantities of municipal solid waste (MSW), which is commonly disposed of by incineration. This has several advantages: it reduces the waste’s volume and sterilizes it while also enabling energy recovery. However, MSW incineration has some notable disadvantages, the most widely debated of which is probably the production and release of persistent organic pollutants (POP) such as polychlorinated dibenzofurans (PCDF), dibenzo-p-dioxins (PCDD), biphenyls (PCB) and naphthalenes (PCN). Of the 210 PCDF and PCDD congeners, 17 are toxic, with hormone-disrupting and carcinogenic properties. Twelve of the 209 PCB congeners and at least 2 of the 75 PCN also exhibit such properties. These POP form in the post-combustion zones of MSW incineration plants and are removed from the flue gas using filtering devices that trap them in the fly ash This thesis concerns the formation and degradation of POP in processes related to MSW incineration. The first paper describes a case study in which PCDD were forming in filters designed to remove them from flue gases, causing emission-related issues in a full-scale MSW incineration plant. It was shown that the PCDD formation was probably due to chlorophenol condensation on the filters’ surfaces. The second paper describes the validation of a cooling probe designed to prevent POP formation during high temperature (>450 °C) flue gas sampling. The results obtained also confirmed that PCDF and PCDD formation takes place at temperatures below 600 °C. In the third paper, three different fly ashes were subjected to thermal treatment under an inert atmosphere in a rotary kiln and in sealed ampoules at 400 °C. The concentrations, degrees of chlorination and congener profiles of the POP in the treated ashes and emitted gases were compared to those for the untreated ashes. The trends observed for PCDF mirrored those for PCN, while the trends for PCDD closely resembled those for PCB. The PCDF congener profiles of the kiln ash were similar regardless of the initial ash composition, suggesting that the mechanisms of PCDF formation were similar in all cases. The fourth paper describes the surface characterization of the three fly ashes studied in paper three by SEM, EDX, XPS and XRD. In addition, the thermal desorption and subsequent degradation of POP from the ashes was studied at temperatures of 300-900 °C. The composition of the gases released as the temperature increased differed between the ashes and depended on their composition. Doping experiments using isotopically labelled PCDF and PCDD suggests that PCDD desorbed at lower temperatures than PCDF. This thesis examines several problems relating to POP formation during MSW incineration, from sampling to the ultimate fate of incineration residues. The results obtained illustrate the wide range of processes that contribute to thermal POP formation and degradation during and after MSW incineration.Förbränning av hushållssopor är en vanlig metod för att hantera ett växande avfallsproblem. Metoden har flera fördelar, såsom minskning av volym och vikt, sterilisering och energiåtervinning. Sopförbränning har dock vissa nackdelar och det mest debatterade är sannolikt utsläpp av persistenta organiska föroreningar (POPs) som polyklorerad dibensofuran (PCDF), dibenso-p-dioxin (PCDD), bifenyl (PCB) och naftalen (PCN). Det finns totalt 210 PCDF- och PCDD- kongener, med mellan ett till åtta klor på kolskelettet, varav 17 är giftiga med hormonstörande och cancerframkallande egenskaper. Även tolv av totalt 209 PCB-kongener samt minst två av totalt 75 PCN-kongener uppvisar liknande egenskaper. Dessa klorerade organiska föroreningar bildas då rökgaserna kyls ner i sopförbränningsanläggningarna och avlägsnas från rökgaserna med hjälp av filter och hamnar i flygaskan. Denna avhandling handlar om bildning och nedbrytning av POPs i sopförbränningsrelaterade processer. Den första artikeln är en fallstudie där PCDD bildas i filtren i en fullskalig sopförbränningsanläggning. Bildningen ledde till förhöjda halter organiska föroreningar i rökgaserna, vilket ledde till ökade utsläpp. Den funna bildningsvägen för PCDD i filtren befanns sannolikt bero på kondensation av klorfenoler på filterytorna. Den andra artikeln är en valideringsstudie av en kylprob avsedd att användas vid rökgasprovtagning vid hög temperatur (> 450 °C) för att undvika bildning av POPs under provtagningen. Studien bekräftade att majoriteten av PCDF- och PCDD- bildning i rökgaser från sopförbränning sker vid temperaturer under 600 °C. I den tredje artikeln berättas om behandling av tre olika flygaskor från olika sopförbränningsanläggningar. Askorna behandlades vid 400 °C i inert atmosfär i både en roterugn och i förseglade ampuller. De resulterande koncentrationerna, kloreringsgraderna och kongenprofilerna av de organiska föroreningarna jämfördes. Likheter hittades mellan PCDF och PCN, medan PCDD och PCB betedde sig på ett annat sätt. Studien fann också att PCDF kongenprofiler i aska som behandlats i roterugnen liknade varandra, oberoende av askornas sammansättning, vilket tyder på en liknande bildningsväg. För den fjärde artikeln, genomfördes ytkarakterisering (SEM, EDX, XPS och XRD) på de tre flygaskorna från artikel tre som sedan hettades upp från 30 °C till 900 °C i vacuum. Det som frigjordes på grund av uppvärmningen samt nedbrytningsprodukter från askorna studerades med hjälp av masspektrometri och infraröd spektroskopi. Studien fann att de gaser som frigjordes när temperaturen ökade skilde mellan askorna, beroende på deras sammansättning. Studien fann också att när aska dopad med isotopmärkt PCDF och PCDD utsattes för samma behandling, frigjordes PCDD vid lägre temperatur än PCDF. Denna avhandling berör flera aspekter av problematiken kring klorerade organiska föroreningar som bildas vid sopförbränning, från provtagning till hur man ska hantera flygaskan. Avhandlingen belyser även olika typer av bildning och nedbrytning av POPs i varma processer kopplade till sopförbränning.
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Plch, Michal. "Návrh technologické jednotky pro odstraňování perzistentních látek při termickém zpracování kontaminované biomasy". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228708.
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The Diploma’s work deals with design to use new methods of cleaning the combustion products for the incinerator of biomass, which guarantees removal of dioxins from the combustion products. Thesis depicts methods of cleaning the combustion products, like ADIOX, using ceramic filters, catalytically filters and methods REMEDIA. Thesis compares constituent methods in terms of effectiveness and according to economic analysis applicable to incinerator of biomass-power output 1 MW. Thesis acquaints with the conception of biomass and with thermic processing, which produces dioxins. Thesis processes using biomass in Czech Republic and plan for using in the future. Thesis processes detailed model of filter using the fabric filters REMEDIA. Suggestion of position of the filter and it is connection to original products line of cleaning the combustion products. Increased pressure loss of the new pipework way and increased consumption of ventilator incinerator is calculated for the new connection. In quest of decreasing the thermal loss of combustion products and in quest of increasing safety of operation is calculated and in quest of increasing safety of operation is calculated proposal of isolation for the filter and pipework. In the end of the thesis is depicted using the technology for decreased amount of dioxins from the fly ash from dioxin filter.
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Xu, Weiguang. "Risk assessment of dietary exposure to PCDD/PCDFs, DL-PCBs and NDL-PCBs of Hong Kong residents". HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1407.
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Cheng, Yao-Chiang, i 鄭銚強. "Investigation of PCDD/PCDF Formation by Inhibitors in Laboratory-scale Experimental System". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/10442761798255006376.
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碩士國立中央大學
環境工程研究所
92
Polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) are very toxic compounds mainly emitted from municipal solid waste incinerators(MSWI). These compounds will affect human health when inhaled. Activated carbon injection (ACI) and SCR decompostition are two major end-of-pipe pollution control technologies currently used. It is proved that addition of inhibitors (such as sulfur, SO2, urea, alkaline materials) could decrease formation of dioxins. Experimental results indicate that addition of sulfur in incineration process can reduce PCDD/F formation. PCDD/F formation can be effectively reduced when S/Cl molar ratio is about 2. Dioxins decrease dramatically at SO2/HCl ratio as 0.55. The sulfur component will react with Cl2 and convent it into HCl. In addition, S or SO2 affect dioxin formation by vulcanizating phenolic precursors and catalysis metal, thus inhibiting chlorination reaction. Calcium hydroxide can reduce dioxin formation by more than 90﹪when Ca/Cl molar ratio is over 0.5. Addition of urea can also reduce PCDD/F formation about 50~87﹪when N/Cl mole ratio is about 0.1. The role of urea is to block catalysis metal and to form complex compounds with Cu and to prevent Ullmann reaction. Inhibition of dioxins formation will be the best way to reduce dioxin emissions. The cost of applying inhibitors for reducing dioxin formation is considerably lower than that of using activated carbon injection (ACI) and SCR decompostition. Adding inhibitors technology has a good potential for controling dioxins formation and emission in the future.
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Tseng, Yi-hon, i 曾亦宏. "PCDD/Fs Distribution Characteristics". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/30737120076424258759.
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碩士國立屏東科技大學
環境工程與科學系
91
Thermal destruction (i.e. incineration) is one of the most effective processes to treat municipal solid waste (MSW) in view of the volume reduction. However, the secondary pollutions come out from the incinerator is a conflict issue about this state-of-art technology. Formation of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the flue gas and ash from the incineration system was recognized by two major pathways. One is incompletely destruction of the waste resources, the other is reformation by the precursors mechanism and de novo synthesis, respectively. Studies showed that the conditions in the post-combustion region are strongly influencing the formation these products of incomplete combustion (PICs). The favored temperature range and high surface area in the particulate matter play the important roles to increase the concentration of PCDD/Fs. The high removal efficiency of particulate active carbon injection was to apply for most of incineration systems to reduce the heavy metal compounds and PCDD/Fs. The adsorption carbon residue in the fly ash stream is still a controversial issue for the final disposal treatment. The preliminary investigation in this study is to analyze the physical and chemical characteristics of fly ash from two different thermal processes ( incinerator and steel arc furnace). The ash samples were collected at the units of air pollution control devices (APCDs). The results showed that PCDD/Fs concentration of fly ash is dependent on the chlorine contents and the active surface area. The comparison between the raw fly ash as received from the APCDs and the treated fly ash by the model precursors is made in this study. The operation parameters and the matrix of fly ash for the physical and chemical characteristics were investigated. Inducing precursors experiments took place in a laboratory scales packed bed reactor. Investigation of the correlation between the precursor compounds and the PCDD/Fs congeners profile is the trust of this study. The remaining PCDD/Fs in the matrix of fly ash would be demonstrated to understand the PCDD/Fs fate and the rate determining step during the PCDD/Fs formation and destruction. Based on these information, to identify the original PCDD/Fs pollution sources from the environmental medium may be possible.
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Liu, Chun-Hu, i 劉純湖. "The PCDD/PCDF/PCB Levels in Breast Milk Samples Collected in Tainan Area". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/ps289u.
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碩士國立成功大學
環境醫學研究所
90
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) are broadly distributed environmental contaminants. PCDDs/PCDFs/PCBs are highly stable in the environment. They are lipophilic and can be bioaccumulated via food chain into human bodies with long half-lives of elimination. The adipose tissue, blood, and breast milk are usually analyzed for the assessment of human exposure to PCDDs/PCDFs/PCBs. Among these three types of specimen, analysis of breast milk for exposure assessment provides two specific advantages. First, the collection of breast milk is noninvasive. Second, the analytical data can be used to assess the exposure of both the mother and the infant. The objectives of the study are (1) to measure the PCDDs/PCDFs/PCBs levels in breast milk samples collected in Tainan area, and (2) to utilize these data to evaluate infant’s exposure via breast-feeding. The samples were collected from NCKU, Sin-Lau, and Chi-Mei hospitals in Tainan city. Breast milk samples were collected from 41 volunteers in these hospitals in years 2000 and 2001. Breast milk lipids were extracted by ethanol and n-hexane, followed by sulfuric acid digestion. For the analysis of 17 PCDDs/PCDFs, the extracts were fractionated with ion exchange (SCX), silica (Si), and Florisil solid phase extraction columns, and the fraction containing dioxins and furans were analyzed by gas chromatography-high resolution mass spectrometry (GC-HRMS). For the analysis of PCBs, only Florisil column fractionation was used, and 36 PCB congeners were analyzed by gas chromatography electronic capture detector (GC-ECD). The average age of the subjects in this study was 30 years (N = 37, SD = 3.6 yrs). The total concentration of 17 dioxin congeners in the breast milk was 213 �b 141 pg/g-lipid. The concentration can be expressed as 12.7 �b 8.40 pg-I-TEQ/g-lipid when the international toxic equivalences (I-TEQs) of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) is calculated, or 14.6 �b 9.26 pg-WHO-TEQ/g-lipid using WHO toxic equivalences (WHO-TEQs). The total concentration of 36 PCB congeners in breast milk was 96.8 �b 96.0 ng/g-lipid. The data represent these mothers’ exposure, and infants’ exposure through breast-feeding nursing can be estimated. Assuming that the breast milk intakes per day for an infant are 805 mL in the first two months after birth, 810 mL in the third month, and 925 mL from the 4th to the 6th month respectively, with an absorption efficiency of 95 %, the average infant’s dioxin/furan exposure was estimated to be 216 �b 129 pg-I-TEQ/day (or 250 �b 148 pg-WHO-TEQ/day). Due to the weight difference between boys and girls, these values translate into 34.9 �b 20.7 pg-I-TEQ/kg/day (40.5 �b 23.8 pg-WHO-TEQ/kg/ day) for boys, and 40.1 �b 23.8 pg-I-TEQ/kg/day (46.5 �b 27.3 pg-WHO-TEQ/kg/ day) for girls. Using the same model, the average infant’s exposure to 36 PCBs was estimated to be 2671 �b 2526 ng/day, or 431 �b 408 ng/kg/day for boys and 495 �b 465 ng/kg/day for girls.
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Wang, Hsiao-Jou, i 王曉柔. "Exposure assessment of PCDD/PCDF/Co-PCBs for workers of secondary copper smelter". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/50353486686424917961.
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碩士國立成功大學
環境醫學研究所
93
The objective of this study was to determine the concentrations of serum PCDD/F/Co-PCBs of operation workers, the concentrations of airbrone PCDD/Fs of working environment, and the relationship between serum PCDD/F/Co-PCBs levels and health index of workers in secondary copper smelting plant. The personal exposure data and time activity pattern were collected with questionnaires. And thirteen blood biochemistry examinations, immunological index and five hormones were examined. All the results were integrated to conduct the PCDD/F/Co-PCBs exposure assessment of workers. 46 blood samples and 4 air samples were collected and analyzed in this study. The highest TEQ levels of airborne PCDD/Fs was 34.8 pg WHO-TEQ/Nm3 sampled in the casting area at plant A, and lowest was in the casting area at plant B. The partitioning of gas/particle data showed the PCDD/Fs in particle phase was higher than gas phase. All workers were grouped to foreign and local workers, then local workers were grouped to high and low-level groups by the median of serum PCDD/Fs (29.5 pg WHO98-TEQDF/g lipid). The average serum PCDD/F/Co-PCBs levels in high, low-level and foreign groups were 41.0、20.9 and 20.4 pg-WHO-TEQ/g-lipid respectively. The TEQ levels of serum PCDD/F/Co-PCBs of all workers （28.6 pg WHO98-TEQDF/g lipid）was higher than that of general populations in Taiwan. Besides the abnormal rates of glucose in low-level group and GGT in foreign group were marginally significant lower than the high-level group, there were no significant differences of blood biochemistry, hormone, and immunological index among three groups. The dominating homologue of PCDD/Fs in blood and air samples are both PeCDFs and HxCDFs, it meant that the workers were potentially exposure to higher levels of PCDD/Fs emitted from secondary copper plant. The major congeners of Co-PCBs were PCB77, PCB169 and PCB126. The regression data showed serum PCDD/F/Co-PCBs were highly correlated with seniority and the exposure indices .The lifetime average daily does （LADD） of workers were met the range of WHO daily tolerance dose. The usage of personal protective measures was suggested to effectively reduce the exposure of PCDD/F/Co-PCBs.
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Lin, Sin-chiou, i 林欣萩. "Effect and contribution assessment of PCDD/Fs in forage from PCDD/Fs emission sources in Taiwan". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/89409309473403624583.
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碩士國立成功大學
環境醫學研究所
95
Literatures showed that the higher PCDD/Fs levels in beef, mutton and milk were related to the higher PCDD/Fs levels in forages. Therefore, the establishment of clean and safe measures for forage production is too impatient to wait. Because of the livestock farm not only wide but scrappy, it will highly cost on manpower and economical recources by field survey in each place. This study is aimed to simulate the PCDD/Fs levels of forage from the pastures nearby the PCDD/Fs emission sources and to assess the contribution of those sources, and then establish the clean and safe zones for forage production. Three types of forage plant which are most commom used and planted on the livestock farm, Napiergrass, Pangolgrass and Silage Corn are selected to simulate PCDD/Fs levels. A and B County were chosen to be conducted in this study, because their high emissions of PCDD/Fs, high density of dairy farm and high production of forage. C county and D County were chosen as control area, because they also have wide pasture and less contaminated by PCDD/Fs. The basic information of pastures, dairy farm, PCDD/Fs emission sources and meteorological data were collected and the data were applied to simulate ambient levels and deposition of PCDD/Fs by atmospheric dispersion model (ISCST3). Then, the Multimedia model was applied to estimate the PCDD/Fs concentrations of environmental media and forage. The results were compared with the maximum limits for PCDD/Fs in feeding stuffs of EU. Finally, the spatial distribution of clean and safe pasture area were mapped by using the geographic information system (GIS). After comparing the simulated PCDD/Fs level to measured PCDD/Fs level of forage plants, the results show the range of their difference was acceptable. As above we could conclude that using multimedia model to simulate the PCDD/Fs level of forages in this study is practicable. The results of ambient PCDD/Fs level and total deposition by using ISC-ST3 atmospheric dispersion model reveal that A County was higher than others and D County was lowest. After using multimedia model to simulate the PCDD/Fs level of forages, we found that all counties have the lowest PCDD/Fs level of forage in winter. Besides, the simulated PCDD/Fs level of three kinds of forages in A County were higher than EU maximum limits (0.75 ng WHO98-TEQPCDD/F/kg, 12% H2O). We only included the PCDD/Fs emission data of the emission sources investigated by Taiwan EPA in this study, and the emission sources which not investigated by Taiwan EPA and some moving emission sources such as motorcycles, burning outdoors and flying dust from soil were excluded.
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SHU, Jing-Fang, i 許菁芳. "The relationship between blood levels of PCB/PCDD/PCDF congeners and abnormal liver function in Yu-Cheng patients". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/10364812442109420204.
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碩士國立成功大學
環境醫學研究所
88
Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzo-p-furans (PCDFs) are among the most widespread environmental pollutants. Accumulation in human tissues with these lipophilic compounds is often considered as a potential threat to human health. Livers are the most sensitive organs observed in toxicological animal studies and consequential liver damages caused by the toxins are commonly observed. Several epidemiological studies have shown that occupational and non-occupational human exposures of PCBs, PCDDs and PCDFs, such as those of PCBs in transformer/capacitor factories and PCDDs/PCDFs in an industrial accident occurring in Seveso, Italy, were linked to abnormalities in liver function. In these studies, levels of total PCBs/PCDDs/PCDFs, rather than levels of specific PCB/PCDD/PCDF congeners, in the blood samples are often used to study their association with the health effects. Abnormalities in liver function and liver cirrhosis were also reported in the Yu-cheng patients in Taiwan. A nested case-control design was used within a cohort of subjects, 2061 Yu-cheng patients in Taiwan, which has been followed up by Guo and his co-workers since 1991. The study aims to investigate the relationship between blood levels of PCB/PCDD/PCDF congeners and observed abnormal liver function in Yu-cheng patients by measuring the concentrations of specific congeners in the blood samples. Gas chromatography-electron capture detection (GC-ECD) and gas chromatography-high resolution mass spectrometry (GC-HRMS) are utilized for the congener-specific measurements. PCB/PCDD/PCDF congener levels in the blood of 41 Yu-cheng patients were analyzed. The average concentration of the total PCDDs/PCDFs of the blood samples was found to be 6893 pg/g-lipid and the concentration of 1,2,3,4,7,8-HxCDF (1741pg/g-lipid) was the highest among seventeen PCDD/PCDF congeners determined in the blood samples. The average total PCBs concentration in the blood samples was found to be 2921 pg/mg-lipid and the concentration of PCB 28/31 (397pg/mg-lipid) was the highest among thirty-four PCB congeners. After adjustment for cholesterol and body mass index (BMI), there were statistically significant positive correlations between liver function and some PCB levels (PCB 28/31, 44, and 189).
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Li, Hsing-Wang, i 李興旺. "Characterization of PCDD/F Emission from Industrial Thermal Processes". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/37920796071536918119.
Pełny tekst źródłaStreszczenie:
博士國立成功大學
環境工程學系碩博士班
96
The emission of polychlorinated dibenzo-p-dioxin and furans (PCDD/Fs) from the different thermal processes was investigated. These thermal processes included aluminum smelting plant, electric arc furnace, fly ash treatment plant, and municipal solid waste incinerators. Seventeen PCDD/F congeners were measured by high resolution gas chromatography/mass spectrometer (HRGC/HRMS). The four secondary aluminum smelters (ALS) yield much higher PCDD/Fs than the aluminum ingot smelters, or 7.94-22.7 vs 0.57-2.67 ng/Nm3, due to a large percentage of waste or recycled aluminum used in the former and over 50% ingot used in the latter. The PCDD/F emission factor is related to either raw materials used or product produced, and the average emission factor of four secondary ALS is much higher than that of aluminum ingot smelters, or approximately 20 times higher based on either raw materials or product. The most important PCDD/F source of input mass in the fly ash treatment plant (the Waelz process) was EAF fly ash, which had a mean PCDD/F content of 18.51 ng/g and contributed more than 99% of the PCDD/F input mass. For the PCDD/F output mass, the major total PCDD/F content of 43.73 and 10.78 ng/g were in bag-filter- and cyclone-ashes, which accounted for about 69% and 17%, respectively. The O/I ratio of total PCDD/F mass and total PCDD/F I-TEQ were 0.62 and 1.19, respectively. Thus, the effects of the Waelz process for the depletion of total PCDD/F mass was positive but minor, while the effect for total PCDD/F I-TEQ was adverse overall. In the amount of 20, 40 and 50 kg/hr powder activated carbon (PAC) injection, the removal efficiencies of PCDD/Fs in the stack flue gas were 86%, 96% and 97%, respectively. By adding an increased amount of PAC, the removal efficiencies were enhanced while the reduction fractions of low chlorinated PCDD/F congeners were much higher than those of highly chlorinated PCDD/F congeners. The addition of bio-solution (NOE-7F) in the raw materials had a dechlorination on the PCDD/F removal and mainly inhibited highly chlorinated PCDD/F formation. The combination of both PAC injection and NOE-7F addition has a high potential for practical application. The usage of filters over the four-year period led to increases of the total I-TEQ levels after the bag filters by 98%-256%, in the three plants. After the replacement of filters, the total I-TEQ after the filters decreased by 53%-89%, in these plants. A great amount of PCDD/Fs were sorbed by the installed filters over four-year period and their subsequent release from filters led to increases of PCDD/Fs levels in the stack flue gases. The release of PCDD/Fs from filters resulted most likely from the blow-off of fine pieces of the aged filter material by the flue gas when the filter was used after a certain period. High PCDD/F concentrations after the filters are attributed conventionally to the memory effect of the filters. The results of this study showed that the raw materials played an important role to PCDD/F formation. Different air pollution control devices could reach different removal efficiency of PCDD/F. How to combine different air pollution control devices (APCDs) to reduce PCDD/F emission effectively is a critical issue. The PCDD/F concentration was measured regularly and replacement of filters or materials of APCDs was also necessary.
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Chen, Shiu-chou, i 陳仕洲. "PCDD/F Characteristic in the Exhaust of Mobile Sources". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/05714094044329176795.
Pełny tekst źródłaStreszczenie:
碩士國立成功大學
環境工程學系碩博士班
96
For these years, mobile pollution emission sources have contributed more and more in domestic polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), This study examined the characteristics of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in the exhaust gases of mobile sources. In this study, 50 vehicles of petrol SUV car, 15 vehicles of diesel oil limousine, 2 heavy-duty diesel vehicles and 10 motorcycles were investigated. The PCDD/Fs emission factors of mobile sources were determined‚ and the overall emission quantity of PCDD/Fs from the domestic mobile sources was estimated. Finally, the influence of these emission sources on the surrounding environment was assessed. The total PCDD/F concentrations exhaust from SUV, diesel vehicles, heavy-duty diesel vehicles and motorcycles are 0.0553, 0.0417, 0.145 and 0.0591 ng I-TEQ/Nm3, respectively. The PCDD/F emission factors from SUV, diesel vehicles, heavy-duty diesel vehicles and motorcycles are 0.113, 0.105, 1.86 and 0.0831 ng I-TEQ/km, respectively. The particulate-phase of PCDD/Fs in the exhaust gases of SUV, diesel vehicles, heavy-duty diesel vehicles and motorcycles are 74.4%, 91.8%, 70.2% and 85.1%, respectively. Moreover, the mean I-TEQ concentration in particulate-phase is 79.8%. Due to the relatively high fraction of PCDD/Fs in particulate-phase, the PCDD/Fs emission can be effectively controlled by reducing the emission of particle in the exhaust gases of vehicles. After using new engine oil old engine oil, the PCDD/Fs concentrations in particulate-phase were reduced 38.2% (from 0.0445 to 0.0275 ng I-TEQ/Nm3) and 58.2%(from 0.0631 to 0.0264 ng I-TEQ/Nm3), respectively, for L type and N type mechanical bicycles. The emission factors of PCDD/F I-TEQ were also reduced 53.5% (from 0.141 to 0.0655 ng I-TEQ/km) and 56.6% (from 0.105 to 0.0456 ng I-TEQ/km), respectively, for L type and N type mechanical bicycles. The trend of PCDD/F concentrations and I-TEQ emission factors indicated that using the new engine oil can reduce the PCDD/Fs emission of vehicles. The research result shows the average PCDD/Fs concentrations in ambient air nearby M site (municipal solid waste incinerators [MSWIs]) is 0.0418 pg I-TEQ/Nm3, we compared cross-section of above PCDD/Fs with that inside the incinerator tunnels and SUV, diesel vehicles, heavy-duty diesel vehicles and motorcycles and found that there is no prominent relationship between cross-section characteristics of PCDD/Fs around the incinerators and inside their tunnels but cross-section characteristics of PCDD/Fs around the incinerators are so similar to out test vehicles. Therefore, we predict concentration of PCDD/Fs n ambient air nearby incinerators should be affected by mobile pollution emission sources which nearby them.
32
Cheng, Pai-Sheng, i 鄭百乘. "Study of Environmental PCDD/Fs Fingerprints and Distribution in Taiwan". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/40544229198384656918.
Pełny tekst źródłaStreszczenie:
博士國立清華大學
化學系
91
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are unwanted byproducts from various combustion processes and numerous chemical industrial processes. The toxic 2,3,7,8-substituted PCDD/Fs are lipophilic and tend to accumulate in carbon-rich matrices and in fatty tissues. PCDD/Fs have been detected in every environmental compartment owing to their chemical, physical and biological stability and long-range transport. Moreover, PCDD/Fs emissions from municipal solid waste incinerators (MSWIs) have become a globally environmental issue. Investigation of the relationship between PCDD/Fs level in stack emission from MSWIs and in ambient air, soil and vegetation provides the PCDD/Fs impact on environment from MSWI emissions. There are six chapters in this thesis. Chapter 1 describes the research motive and purposes. Chapter 2 introduces the methods of PCDD/Fs sampling, PCDD/Fs analysis, ISCST3 model, PCA and HCA statistics. The title of chapter 3 is “Comparative study of monitored levels of PCDD/Fs in ambient air, soil and ISCST3 model predictions in the vicinity of a municipal solid waste incinerator in Hsinchu”. As a result of the newly construction of Hsinchu city MSWI, this study seized a wonderful opportunity to research how PCDD/Fs emission from a new MSWI equipped with modern APCDs could impact the ambient environment. This chapter presents the PCDD/Fs measured in ambient air and in soil around Hsinchu city MSWI during the trial burns in 2000 and compared to those measured in 2001 when it was fully operational. Concentration discrepancies between instrumental quantification and ISCST3 model prediction of ambient air were examined to test the precision and correlation among these two different types of method. Results of PCA, HCA and ISCST3 prediction reveal that Hsinchu city MSWI is not the major PCDD/Fs emission source to the ambient region. Human activities and unknown PCDD/Fs sources may fill up the gap among the model predictions and the instrument measurements. A systematic decrease of PCDD/Fs concentration in the ambient air from the northeast area to southwest was observed. This decreasing trend along the direction of wind is attributed to the heavy industrial activities on the northeast of Hsinchu city and wind flow towards southwest. Higher PCDD/Fs levels in the ambient air were found during spring and lower concentration was observed in summer. We recommend monitoring MSWI on a regional basis where the industrial and human activities are dense as in Taiwan. The title of chapter 4 is “Distributions and principal sources of PCDD/Fs in ambient air, soil and vegetation in the vicinity of Taichung city and Chiayi city municipal solid waste incinerators together with an arc furnace in Kaohsiung”. Most related researches generally hypothesize a potential emission source at first, and measure the environmental PCDD/Fs levels in simply one or two kinds of matrices to evaluate the influences from targeted source. In this study, PCDD/Fs in four matrices including stack gas, ambient air, soil and vegetation were collected and analyzed from or in the vicinity of Taichung city MSWI, Chiayi city MSWI and one arc furnace in Kaohsiung city, respectively. The main purpose is to investigate the PCDD/Fs distributions in the three areas on the basis of regional viewpoint, and find out the major PCDD/Fs sources in the area. The determination of PCDD/Fs in leaves was carried out using modified and verified USEPA method 1613B. Different type of PCDD/Fs source in the respective investigation areas were proposed: 1. PCDD/Fs in the vicinity of Taichung city MSWI might because of the human activity like the case of Hsinchu MSWI; 2. medical waste incineration was probably the major PCDD/Fs source in the ambient environment of Chiayi city MSWI; 3. the arc furnace was considered one of the principal PCDD/Fs emission source to the surrounding environment in Kaohsiung Lin Hai industrial district. Furthermore, high PCDD/Fs amount occurred in soil resulting in positive correlation between TOC and PCDD/Fs content. It is suggested that banyan leaf could be selected as an atmospheric PCDD/Fs biomonitor in Taiwan. The title of chapter 5 is “Nationwide PCDD/Fs levels in ambient air, soil and vegetation in Taiwan”. Reported data/results from the existing survey projects and our lab were collected and integrated into the first “Taiwan Environmental PCDD/Fs Database” based on the UNEP guidance document. Taiwan is a small island populated with twenty-two million people in the west living in an area of 36,179 km2. High population density leads different human lives and activities comparative to the continental countries. For the first time, PCDD/Fs levels in ambient air, vegetation and soil around 19 MSWIs and samples from urban areas in Taiwan are discussed and summarized to bring up a nationwide view of dioxin distributions. Typically, correlation between PCDD/Fs levels in ambient air, soil and vegetation was not observed. The MSWIs are therefore not the only or major dioxin emission source. The Mucha MSWI showed clear influence on ambient PCDD/Fs concentrations, i.e. when comparing the previous and currently improved APCDs. Due to short of data, conclusions can not be made between human activity (population or industrial park) distributions and dioxin level distributions in Taiwan. It is suggested regional (county) basis monitoring instead of the measurements simply surrounding MSWIs, and extended to a nationwide monitoring system in the long run. The title of chapter 6 is “Investigation of meteorological factors influences on PCDD/Fs levels in ambient air using evidences from typhoons”. PCDD/Fs congener concentrations and profile in ambient air under stable weather condition have been proven readily altered by meteorological factors including temperature, wind, rain and air mass origin. However, little has been reported for the atmospheric PCDD/Fs condition right after severe weather variations. This is the first study aiming at the influences of meteorological factors on dioxin congener levels and distributions in ambient air exactly after typhoons. High rainfall and wind speed are both verified to reduce the PCDD/Fs level in ambient air, whereas rainfall influences the most. Relation between rain rate and reduced PCDD/Fs concentration in ambient air samples after typhoons was successfully correlated with an exponential growth curve. High wind speed eliminates the PCDD/Fs concentration in air immediately, but the affect of rain is usually reflected several hours later. PCDD/Fs levels in gaseous phase or particulate phase showed the same trend of variations. It is consequently suggested that both PCDDs and PCDFs in gaseous phase and in particular phase were persistently rose back to their original levels after the typhoon, but rainfall slow down the recovering speed in particulate phase. Severe meteorology factors altered the PCDDs to PCDFs ratio in ambient air, but not the profiles. Moreover, PCDD/Fs level in ambient air would revive in one or two days after the strict weather. These phenomena reveal that atmospheric PCDD/Fs level in Taiwan is not likely to become lower in summer or in autumn due to the prevalence of typhoon in these seasons. A long-term steady weather without heavy rain or high average wind speed is important during atmospheric PCDD/Fs measurement. If time and resources are permitted, chronic ambient air monitoring should be the best strategy to acquire faithful, representative and accurate data.
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Chen, Chien-Cheng, i 陳建呈. "Study the Catalytic Effects of Precursors for PCDD/Fs Formation". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/06786498972206022473.
Pełny tekst źródłaStreszczenie:
碩士國立屏東科技大學
環境工程與科學系所
97
The precursors of Dioxin, such as chlorophenols, chlorobenzenes, and polycyclic aromatic hydrocarbons are combined with fly ash surface, the role catalytic metals, and a condensation reaction to form Dioxin compounds. A powdered activated carbon injection is used to effectively control and adsorb dioxin compounds in the flue. However, when the exhaust of the previous reaction is disturbed, small particles of fly ash may re-enter the air pollution prevention equipment to form dioxin and furan. In this study, the bag house of a waste incinerator was used in laboratory simulations. The results of the study show that adding 0.2% trichlorophenol onto fly ash forms a PCDD/Fs concentration of 27.9 ng/g, whereas adding 0.5% chlorobenzene onto fly ash forms a PCDD/Fs concentration of 8.3 ng/g. Therefore, the addition of trichlorophenol is more favorable than chlorobenzene because the trichlorophenol forms a dioxin concentration that is 2.4 times greater. Furthermore, adding 0.1% pentachlorophenol onto the fly ash produces a PCDD/Fs concentration of 142.2 ng/g, and adding 0.2% pentachlorophenol produces a PCDD/Fs concentration of 166.0 ng/g. Compared to the aforementioned trichlorophenol, the pentachlorophenol forms a dioxin concentration that is at least 4.1 times greater. Up to now, pentachlorophenol most effectively treats dioxin-type compounds in the flue. Also, increasing the concentration of pentachlorophenol subsequently increases the adsorbed concentration of PCDD/Fs. Further simulation revealed that the addition of mercurydichloride and trichlorophenol increased the PCDD/Fs concentration from 27.9 ng/g to 111.5 ng/g. Certainly, the mercurydichloride triples the adsorption of dioxin compounds. In conclusion, adding chlorophenol compounds, chlorobenzene, diphenyl furans, and polycyclic aromatic hydrocarbons onto fly ash generated positive trends of PCDD/Fs adsorption. The addition of chlorophenol compounds and polycyclic aromatic hydrocarbons resulted in large positive trends of PCDDs species adsorption. The addition of chlorobenzene and dibenzofurans resulted in large positive trends of PCDFs species adsorption.
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Guan-YuChen i 陳冠宇. "A Study on PCDD/Fs Scavenged by Cloud/Fog Water". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/793s3b.
Pełny tekst źródłaStreszczenie:
碩士國立成功大學
環境工程學系
107
Precipitation is one of the important sedimentation mechanisms of pollutants in the atmosphere, but the literature of Dibenzo-p-dioxin and Dibenzofuran (PCDD/Fs) deposition in cloud/fog water is still absent. However, droplets of cloud/fog water are much smaller and have a much higher surface-to-volume ratio compared to rain which might make it more efficiency in PCDD/F sedimentation. Therefore, we investigate PCDD/Fs scavenged by cloud/fog water in this study in order to figure it out. Sequential cloud/fog water samples were collected for each cloud event during January 17th to February 24th, 2018 and January 15th to February 16th, 2019. The cloud water samples were combined into one to reach 20 L for PCDD/F measurement due to the low solubility of PCDD/Fs in water. There were 3 and 11 events happened during collecting period in 2018 and 2019, respectively, but only 8 events were analyzed in 2019 because of too short cloud/fog water event period or too low liquid water content. On the other hand, the ambient air sample were collected during January 14th and 28th, 2019, with 7 samples. Total PCDD/F-WHO-TEQ concentration collected by active fog collector in cloud/fog water samples in 2019 (mean: 1.35±1.80 pg WHO-TEQ L-1) averaged higher than the values of passive one (mean: 0.769±1.23 pg WHO-TEQ L-1). There might mix with a little bit rain in cloud/fog water sample collected by passive fog collector, which made liquid water content (LWC) for passive fog collector larger than LWC for active one. Compared to scavenging coefficient of PCDD/F-WHO-TEQ of passive fog collector (mean: 2.24×105±2.96×105), scavenging coefficient (C-cloud/C-air) of PCDD/F-WHO-TEQ of active one was larger (mean: 4.20×105±3.60×105) in 2019. The cause of PCDD/F scavenging coefficient difference contributed to cloud/fog water sample mixing with rain which collected by passive fog collector. Besides, scavenging coefficient of PCDD/F-WHO-TEQ of passive fog collector in 2018 (mean: 3.20×105±3.26×105) averaged higher than the results of passive one in 2019 due to rich cloud and fog during collecting period in 2018. Then, compared to PCDD/F scavenging coefficient of precipitations (around 1.9×105), the scavenging coefficient of cloud/fog water in 2019 was larger. On the other hand, compared to scavenging ratio of PCDD/F-WHO-TEQ of passive fog collector (mean: 0.056±0.074), scavenging ratio (C-cloud/C-air *LWC) of PCDD/F-WHO-TEQ of active one was lower (mean: 0.033±0.029) in 2019. The reason might connect with higher LWC of passive fog collector where PCDD/Fs in the atmosphere could be scavenged by more cloud/fog water and rain. Besides, scavenging ratio of PCDD/F-WHO-TEQ of passive fog collector in 2018 (mean: 0.254±0.236) averaged higher than the results of passive one in 2019 due to higher LWC and rich cloud and fog during collecting period in 2018. Additionally, PCDD/F scavenging ratio of cloud/fog water was smaller than that of trace elements (ranged from 0.11- 0.56) since trace elements are easier to dissolve in water than PCDD/Fs. In conclusion, the obtained scavenging ratios of PCDD/Fs by cloud/fog water are crucial for clarifying the effect of cloud/fog water on the deposition of atmospheric PCDD/Fs.
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Chen, Che kuan, i 陳哲寬. "Characteristics of size distribution of PCDD/Fs and heavy metals in bottom ash and mass distribution of PCDD/Fs in the selected municipal solid waste incinerators". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/50228623027612930557.
Pełny tekst źródłaStreszczenie:
博士國立屏東科技大學
環境工程與科學系所
96
This study investigated the size distribution of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and heavy-metals in bottom ash from four selected municipal solid waste incinerations (MSWIs). The weight fractions of bottom ashes in different particle sizes were also investigated. Finally, PCDD/F mass distributions in the whole incinerator during start-up process have been addressed as well. The significant conclusions of this study are as follows: 1. The major peak in the particle size distribution for bottom ash of MSWI A was found in a particle size of 1 to 2.36 mm, where the weight percentage was 33.2%. For MSWIs B, C and D, the major peak was all located at the particle size range the 2.36–4.75 mm, where the weight percentages were 31.7%, 38.9% and 28.4%, respectively, with averaged 33.0%. 2. For the four selected MSWIs, the major peak in the particle size distribution for the PCDD/F content was found in a particle size <0.21 mm, that is, 28.4, 16.1, 70.1 and 12.5 pg I-TEQ/g, respectively, with averaged 25.8 pg I-TEQ/g. Furthermore, it was also found that PCDD/F content increased with decreasing particle size. 3. For PCDD/F congener profiles in bottom ashes of the four selected MSWIs, OCDD and 1,2,3,4,6,7,8-HpCDD in rank are the most abundant congeners in PCDDs, while OCDF and 1,2,3,4,6,7,8-HpCDF are the most abundant congeners in PCDFs. 4. Hg and Cd contents increased with decreasing particle size of bottom ash from the four selected MSWIs. Most Fe concentrated in the middle particle size. The Pb, As, and Mn size distributions of the bottom ashes were all bimodal size distribution, indicating that the above metals concentrated in both fine and coarse particles. 5. The Pb, Hg, Cd, As and Fe contents in the bottom ashes of the four selected MSWIs were between 842~3160, 0.0394~0.338, 1.79~11.4, 5.65~16.5 and 41000~120000 mg/kg, respectively. The wide ranges of the metals content were due to the differences in the physical and chemical composition of the wastes among the four selected MSWIs. 6. The total PCDD/F emission factors were Stack (8.47 μg/ton-waste; 0.454 μg I-TEQ/ton-waste), BR (58.2 μg/ton-waste; 3.54 μg I-TEQ/ton-waste), SH (4.40 μg/ton-waste; 0.306 μg I-TEQ/ton-waste), EC (961 μg/ton-waste; 31.9 μg I-TEQ/ton-waste), SDA (100 μg/ton-waste; 3.66 μg I-TEQ/ton-waste), FF (1870 μg/ton-waste; 160 μg I-TEQ/ton-waste) and FAP (3610 μg/ton-waste; 323 μg I-TEQ/ton-waste), respectively. PCDD/Fs might be formed (674 μg/ton-waste; 128 μg I-TEQ/ton-waste) during transportation process. 7. The total emission amount of PCDD/Fs from Stack, BR, SH, EC, SDA, FF and generation were 0.00484, 0.0377, 0.00326, 0.340, 0.0390, 1.70 and 1.36 g I-TEQ/week. Besides, total emission amount of PCDD/Fs from the stacks in this MSWI was 0.596 (=0.00484×(52×2.35+1)) g I-TEQ/week with considering the start-up operations. Therefore, mass distribution ratios of PCDD/Fs in g I-TEQ/week from Stack, SH, EC, SDA, FF, generation and BR in star-up operations were 14.6%, 0.1%, 8.3%, 1.0%, 41.7%, 33.4% and 0.9%, respectively. The main PCDD/F source in the MSWI was from fly ash (~85%) although emission during start-up process was 2.35 times larger than that of a whole year’s normal operations. The above results indicated that main PCDD/F source in the MSWI was from fly ash. However, the fly ash is easily controlled and PCDD/Fs emitted from stack flue gases will be difficult to be handled. Therefore, we should pay more attention on PCDD/Fs emission from flue gases especially from start-up process.
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TE, LO MING, i 羅明德. "Assess PCDD/Fs Transfer in the Environmental Medium by Fugacity Model". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/35089849284783410246.
Pełny tekst źródłaStreszczenie:
碩士國立屏東科技大學
環境工程與科學系
94
Following the development of civilization, the releases of man-made chemicals to the environment are increased day by day. Many among these substances are toxics. The common monitoring and modeling methods were used to evaluate fates of these compounds and their concentrations in the various parts of environment. Although the actual concentrations could be monitored through field sampling, it was costly and labor-intensive. As to the modeling, different models need to be used in order to account for chemical releases to different media. In addition, the modelers require highly specific knowledge and large amount of meteorology and hydrology data. On the other hand, the multi-media Fugacity model showed its simplicity and good functionality for determining chemical fates in multimedia transport, air, water, soil and others. It could predict the equilibrium concentrations of chemicals in various media compartment, justify the needs for further sampling, analysis and assessment, and further reduce the labor and cost for risk assessment. In order to evaluate the ability of the Fugacity model for simplifying the risk assessment, this study selected a MSWI. Using the data from the permit applications, this study modeled the fates of various pollutants by the Fugacity model and further explored the feasibility of simplify the process of risk assessment. This study would focus on 17 congeners. After collecting the emission data from the permit applications, this study further analyzed by USEPA FIRE databank to generate the emission rate and amount of pollutants. After further modeling efforts by Fugacity simulation, these results were compared with the monitoring data and were used for risk assessment. The estimated total PCDD/Fs concentration were 7.59E-06 ng/Nm3 for air, 5.49E-06 ng/L for water, 6.84E-04 ng/g for soil and4.86E-04 ng/g for sediment. The model predictions were lower than monitoring data less one order. It conjectured that sources contribution and modeling bulk dimention. Mass fluxes between the compartments were calculated. The results show that main part of PCDD/Fs from the stack emission fall down to soil mainly, minor part moves to sediment compartment, then others medium. From the model estimates, major mass fluxes coming from emission source were shown to go to the soil and water through wet/dry deposition, then go to degradation mainly in the soil(99.5~89.2%) and sediment(10.2~0.4﹪). The results of this study indicated that the Fugacity model is obvious easier, simpler, more versatile, and faster mean. It can save labor and money. Therefore, the Fugacity model can be used as the screen tool in risk assessment or exposure potential in order to examine the fates of certain chemicals after their releases to the environment. It can also be used in the environmental impact assessment and quality management to justify the emission control of chemicals.
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Bai, Shih-Ting, i 白士庭. "Characterization of PCDD/Fs and dl-PCBs Emitted from Woodchip Boilers". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/68990617957898043589.
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碩士國立中央大學
環境工程研究所
105
This study characterizes the formation and emission of PCDD/Fs and dl-PCBs in two woodchips boilers during different operating periods. Two woodchips boilers (referred to as Plant A and B) investigated in this study are located in northern Taiwan. The sampling program of Plant A was conducted during different operating stages, including start-up, normal operation and shut-down periods. The results indicate that PCDD/F and dl-PCB concentrations (588.2 ng/Nm3) at APCDs inlet during the start-up period are much higher than those measured during normal operation and shut-down periods due to unstable combustion conditions. Concentrations of PCDD/F and dl-PCB (41.05 ng/Nm3) measured at APCDs inlet during the shut-down period were even lower than that measured during the normal operating period. It is due to the lack of carbon and chlorine sources since woodchip was not fed into the boiler during the shut-down period. The Plant B was investigated under three operating conditions, including full feed loading with injection of activated carbon, full feed loading without injection of activated carbon and half feed loading with injection of activated carbon. PCDD/Fs and dl-PCBs concentrations (113.6 ng/Nm3) measured at APCDs inlet during the half feed loading are lower than those measured during the full feed loading (139.4 ng/Nm3) due to the reduction of input woodchips. The removal efficiences of gas-phase PCDD/Fs and dl-PCBs achieved with ACI+BF are 95.60% and 92.05%, respectively, which are higher compared to the case without injection of activated carbon (85.74% and 79.76%, respectively). It demonstrates that gas-phase PCDD/Fs and dl-PCBs emissions can be effectively reduced by activated carbon injection. Durig full feed loading with the injection of activated carbon, PCDD/F and dl-PCB concentrations at APCDs inlet of the Plant A are significantly higher than those measured in the Plant B, due to the lower combustion temperature (500-850 oC) compared with Plant B (850-925 oC). Combustion condition remarkably affects PCDD/F and dl-PCB formation within the woodchip combustion process. The TEQ concentration of PCDD/Fs measured at the stack of the Plant A during different operating stages are significantly higher than the emission limit, while those of Plant B are lower than the regulation limit (0.5 ng I-TEQ/Nm3). For both Plants A and B, solid-phase PCDD/Fs dominate at APCDs inlet during different operating conditions because combustion of woodchips generates high concentration particulate matter. Different operating stages of woodchips combustion do not affect distributions of PCDD/F congeners significantly. Major PCDD/F congeners at APCDs inlet of Plants A and B during different periods include 1,2,3,4,6,7,8-HpCDF, 1,2,3,4,6,7,8-HpCDD and OCDD. The composition of feeding materials and different operating conditions affect the distributions of dl-PCB congeners. Concentrations of dioxin (PCDD/Fs+dl-PCBs) in the BF ash of Plants A and B during full feed loading with injection of activated carbon are measured 979.2 and 406.2 ng/g. Removal efficiencies of PCDD/Fs and dl-PCBs of the Plant A are 95.56% and 88.63%, respectively, while those of the Plant B are 99.29% and 94.94%. PCDD/Fs and PCBs emission factors of Plant A are 17.24 and 1.120 μg WHO-TEQ/ton, respectively. For the Plant B, the emission factors of PCDD/Fs and PCBs are 1.520 and 0.1400 μg WHO-TEQ/ton, respectively.
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張庭睿. "Inhibition on Formation of PCDD/Fs in Fly Ashes of Incinerators". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/70212165780066569976.
Pełny tekst źródła
39
Chang, Chia-chia, i 張家嘉. "Characteristics of PCDD/F Emissions from Nonferrous Secondary Metal Smelting Industries". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/52994620936537946573.
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碩士國立中央大學
環境工程研究所碩士在職專班
99
Dioxin is one of the most toxic persistent organic pollutants (POPs). In recent years, many countries are investigating the concentrations and distributions of dioxin in the stack gas and wastes from nonferrous secondary metal smelting industries to understand its generation and distribution. With the above-mentioned information, they are able to make suggestions for the source reduction and process modification. This study aims to compare the characteristics of dioxin generation from secondary copper smelting industry with three different feedstock compositions, which are primarily composed of copper, copper scrap recycling in plant and copper scrap recycling plant outside. As for aluminum secondary metal smelting industry, the characteristics of dioxin formation with three feedstock compositions that mainly consists of aluminum cutting material, tire aluminum ring and aluminum scraps are investigated. Even if the feedstock ratios are different, the results indicate that the contributions of dioxin congeners in stack gas and waste are similar. Moreover, the international toxicity equivalency concentration contributed by the same species are close as well. 10-20% of the international toxicity equivalency concentration is from PCDD while the rest is attributed to PCDF. PCDF is the dominating species. The dominating species for PCDD and PCDF are 12378-PeCDDand 2378-TCDD, and 23478-PeCDF and 234678-HxCDF, respectively. Furthermore, the dioxin concentration from copper secondary metal smelting industry (2.92~12.4 ng I-TEQ/Nm3) is significantly higher than that from aluminum secondary metal smelting industry (0.14~0.25 ng I-TEQ/Nm3). For both industries, dioxin tends to accumulate on the particle surface because of its physical and chemical properties. Therefore, dioxin is mostly distributed in solid phase. While the particles in stack gas are collected by the air pollution control equipment, the dioxin concentration in solid phase decreases as well (0.13~0.40 ng I-TEQ/Nm3) and it meets the emission standard (1.0 ng I-TEQ/Nm3). In contrast, PCDD/F concentrations based on toxic equivalent in fly ashes ranged from 0.466 to 28.8 ng I-TEQ/g. That is significantly higher than the standard for the hazardous industrial waste regulated by Taiwan EPA. Hence, how to properly dispose of highly dioxin contaminated fly ash remains a great concern.
40
WINNER i 江俊穎. "Effects of Differential Fuels on the Distribution Characteristics of PCDD/Fs". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/63030464882105518048.
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碩士大葉大學
環境工程學系碩士在職專班
95
The effects of diifferential fuels on the distribution characteristics of PCDD/Fs was explored in this study for investigating the municipal solid wastes (MSW) incinerator, industrial wastes incinerator, and burn-wood boiler. The information was obtained from the measurement report submit to the environmental protection bureau. Before comparing the concentration (corrected to 11% oxygen concentration) and the species of dioxins, the accuracy for the sampliy method and the reasonableness of the data were investigating carefully. The results in this study indicated that (1) Normal garbage will make 2, 3, 4, 7, 8-PCDF and then 2,3,4,6,7,8-HCDF and 1, 2,3,6,7,8-HCDD. (2) The industrial garbage will make 2,3,4,7,8-PCDF and then 2,3,4,6,7,8-HCDF and 1,2,3,6,7,8-HCDF. (3) The burn-wood boiler will make 2,3,4,7,8-PCDF and then 1,2,3,7,8- PCDD and 2,3,7,8-TCDD. Therefore, the concentrations of 2, 3, 4, 7, 8-PCDF Dioxins chemical composition will be the mainly production from three different types of incinerators.
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Chen, Hsiu-Ling, i 陳秀玲. "Effect of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) exposure on Taiwanese: Investigation on environmental sources of PCDD/Fs and risk assessment on exposed population". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/03014672452932361590.
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博士國立成功大學
基礎醫學研究所
92
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) is a group of toxic substances generated unintentionally as by-products from human activities such as combustion, paper processing, and pesticide production. Most PCDD/Fs are resistant to environmental and biological degradation, and dispersed into environment through water, soil, foods, and the atmosphere. It has been estimated that more than 95% of serum PCDD/Fs are attributable to the consumption of various food groups. The aim of this study, therefore, was to compare the serum PCDD/Fs patterns of residents living in the vicinity of functioning incinerators and to examine how dietary patterns or air exposure were associated with their serum PCDD/F concentrations. In addition, this study intended to estimate the average daily intake of dioxin-like compounds and to examine the interactive influence of CYP1A1 genotypes and PCDD/Fs exposure on health influences. One thousand seven hundred and twelve volunteers living near incinerators were recruited from 2000 to 2003. All selected subjects were between 18-65 years old and proportionally chosen from each age group based on population distribution. In addition, they had to have lived within a 5-km radius of the incinerator for at least 5 years. All subjects needed to complete health and dietary questionnaires, 13 blood biochemistry test, analysis of genetic polymorphism at CYP1A1/Msp 1 and Nco 1, and serum PCDD/Fs analysis. Average serum PCDD/Fs levels were 19.7 pg WHO-TEQ/g lipid. Higher serum PCDD/F levels were found in older than in younger subjects, and higher PCDD/F concentrations were found in females than in males. In addition, nonsmokers and passive smokers showed higher levels of PCDD/Fs than active smokers. The serum PCDD/Fs levels of people were not associated to the ambient exposure dose or operated period of incinerator. However, distributions of 17 serum PCDD/Fs congeners were affected by different ambient exposure dose. For dietary analysis, serum PCDD/Fs level was significantly higher in non-vegetarian than vegetarian, and higher in subjects responding they often eat local food than those responding never. The result also presented the distribution of serum PCDD/Fs levels in different groups. The highest serum PCDD/Fs level was observed in a fishing port (24.1 pg WHO-TEQ/g lipid), the following is in industrial area (21.8 pg WHO-TEQ/g lipid), in rural area (17.9), in urban area (17.0), and the lowest is in urban and rural area (16.5). The significant positive multivariate-adjusted association was found between serum PCDD/F levels and sea fish intake and negative in egg and tofu intake. We might suggest that if people took more soybean protein such as tofu, then lower serum PCDD/Fs levels might be expected in relation to less body fat content and induction of metabolic enzymes such as quinone reductase and UDP-GST. Significantly elevated levels of glucose and blood urea nitrogen were found in those from low to high serum PCDD/Fs levels, and PCDD/Fs levels were found to be positively associated with hypertension and diabetes even after adjusting for age, sex, BMI and smoking status. In addition, the results reported here also suggest that the GPT levels may be modified by interaction of CYP1A1/Msp 1 genotype and dioxin exposure levels after adjustment. The estimated average daily intake of dioxins was 0.393 pg WHO-TEQ/kg body weight/day. Sea fish presented the highest concentration of PCDD/Fs and the followed was fresh water fish and beef. The ambient exposure contributed 2.56% of daily intake and dietary intake contributed 97.4%. However, the vegetables were still not been included for estimating the dietary intake, and it might be under-estimated. Further studies are needed to characterize the variation of other related genes to verify the correlation between serum PCDD/Fs levels and other health effects. Moreover, it will be necessary to set a strategy in foodstuff to prevent the excess PCDD/Fs accumulation from the food planted or grown originally near a probable contaminant source.
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Tsai, Shian-Sheng, i 蔡憲昇. "Evaluation of the Emission Characteristics of PCDD/Fs from Electric Arc Furnaces". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/93325308857238729568.
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碩士國立中央大學
環境工程研究所
91
Many studies indicate that both municipal waste incinerators (MWIs) and the industrial activities containing combustion processes are important sources of PCDD/F emissions. Local studies indicate that dioxin in ambient air originates mainly from electric arc furnaces. Electric arc furnaces (EAFs) have been identified as the major sources of PCDD/F emissions in Taiwan. Two kinds of EAFs including the direct evacuation system and the building evacuation system are selected for measuring the dioxin emission. Results indicate that the PCDD/F concentration of stack gas in EAF-A was 22.50 ng/Nm3, and the total Toxic Equivalent Quantity (TEQ) concentration was 1.72 ng I-TEQ/Nm3. The PCDD/F concentration of stack gas in EAF-B was 2.19 ng/Nm3, and the TEQ concentration was 0.14 ng I-TEQ/Nm3. This result showed that the direct evacuation system emitted more dioxin than the building evacuation system. The other results obtained on gas/particulate partitioning of PCDD/Fs in EAFs indicate that more than 90% in the particulate-phase before the flue gas passed through APCD. The emission factor of EAF-A is 11.62 ng-I-TEQ/kg-product, while 7.36 ng-I-TEQ/kg-product is found for EAF-B. 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF were the major contributors of the dioxin concentrations in each phase and the percentage of PCDD/F in particulate phase increases with the chlorination level of the PCDD/F congeners. The distributions of total Toxic Equivalent Quantity (TEQ) concentrations on 2,3,4,7,8-PeCDF at each sampling site were about 50%.
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Hsieh, Yu-Fen, i 謝瑜芬. "Preliminary study on the destruction of gaseous PCDD/Fs with SCR catalyst". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/19221152350793814848.
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碩士國立中央大學
環境工程研究所
91
Selective catalytic reduction (SCR) units are commonly used in coal-fired power plants for controlling NOx emissions. In some municipal waste incinerators (MSWIs), SCR units have also been installed. In the late 1980s, it was incidentally found that SCR also decomposes polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Oxidation of representative congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated debenzofruans (PCDFs), was investigated on commercial V2O5-WO3/TiO2-based catalysts by passing the gas streams containing specific concentrations of PCDD/Fs at controlled temperature and space velocity in this study. A decrease in the amount of PCDD/Fs adsorbed on catalyst with increasing reaction temperature was found for species 1,2,3,4-TCDD and OCDD. The conversion rate of 1,2,3,4-TCDD was faster than that of OCDD. At 200℃, one derivate of seventeen 2,3,7,8-substituted dioxin homologues was detected in downstream flow, but no derivates were found at 250℃. Adding oxygen into the gas stream would lower the quantity of OCDD adsorbed on catalyst. Experiment conducted in the presence of water vapor exhibits a higher removal efficiency of species OCDF than that without water vapor. Three derivates of seventeen 2,3,7,8-substituted dioxin homologues are generated from reactant OCDD, and the concentration of toxic equivalent quantity was higher than that without water vapor.
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Chen, Chung-Yi, i 陳忠義. "Model Simulation of PCDD/Fs Fate and Pathway in the Soil Medium". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/53494544824951677166.
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碩士國立屏東科技大學
環境工程與科學系
94
The metal refinery industry is a significant source of PCDD/Fs emissions to environment. The objective of this study was to simulate the transport of these PCDD/Fs compounds with a one dimensional flow and fugacity-based multimedia fate model. The estimated total PCDD/Fs concentration were 0.02083 ng/Nm3 for air, 0.10252 ng/L for water, 2849.613 ng/kg for soil and 63.325 ng/kg for sediment. Mass fluxes between the compartments were calculated. The results show that main part of PCDD/Fs from the stack emission fall down to soil mainly, minor part moves to sediment compartment, then others medium. From the model estimates, major mass fluxes coming from emission source were shown to go to the soil and water through wet/dry deposition, then go to degradation mainly in the soil (97.7 %) and sediment. Homologue profiles indicated that the lower chlorinated compounds need the longer term to be removed from particulate matter. The advection effect plays the most important role. The estimated 2,3,7,8TCDF mass flux partition was 47.07 % for air. The total PCDD/Fs concentration was about 2849.6 ng/kg from model prediction in soil. Estimated concentration in soil tentatively matches to the monitoring data near to the metal refinery plant. However, the homologue profiles show the different trend between PCDDs and PCDFs for water medium. The mechanism of pathway for PCDD/Fs is not clear in this prelimary simulation, a more detailed assessment is necessary.
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Wu, Yu-Ling, i 吳育霖. "Study of Conversion Characteristics for PCDD/Fs onto the Fly Ash Medium". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/00912996089952705698.
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碩士國立屏東科技大學
環境工程與科學系
93
The combustion treatment process of a municipal solid waste incinerator (MSWI) may cause the level of environmental impact. Especially, the formation of polychlorinated dibenzo-p-dioxin and polychlorinated furan (PCDD/Fs) in the fly ash medium from incineration system is investigated in this research project. The preliminary results are to analyze the physical and chemical characteristics of fly ash from the different units of MSWI (i.e. boiler, scrubber, and bag filter). The results showed the chlorine contents in the boiler ash of M and S incinerator were 4.9 and 15.6 mg/g, the PCDD/Fs concentration of M and S incinerator were 2.3 and 0.9 ng/g, respectively. The chlorine contents in the bag filter ash of K and S incinerator were 20.9 and 163.6 mg/g, the PCDD/Fs concentration of K and S incinerator were 27.0 and 42.4 ng/g, respectively. The correlation between the chloride contents and the PCDD/Fs concentration in ashes is pronounced for S incinerator. It suggests that the characteristics of physical and chemical in ashes may be changed due to the different waste was combusted. The dominant PCDD/F congener contribute to the major toxic equivalence is 2,3,4,7,8-PeCDF. The PCDD/Fs concentrations onto the ashes medium is positively related to the specific surface area (BET) and chlorine contents in the K incinerator. The PCDD/Fs concentrations onto the fly ashes are dependent on the total carbon and chlorine contents in the S incinerator. But the BET surface area doesn’t show the positive correlation. It demonstrates the physical and chemical characteristics of fly ash may be affected by the scrubber injection mode. After the continuous extraction for fly ashes, the PCDD/Fs residue concentration still remain 4 ng/g onto the fly ash medium. The residue recovery percentage for PCDDs and PCDFs are 12.0% and 6.3%, respectively. Copper chloride and dibenzofurans were added to the fly ash medium to stimulate the formation of PCDD/Fs. The experimental results revealed that the formation of PCDD/Fs concentration in the copper chloride, dibenzofuran and the mixture (both the copper chloride and dibenzofuran) is 369.5, 86.9 and 5,307.8 ng/g, respectively. The PCDD/Fs concentration of the mixture experiment was increased intensively. Since the catalytic effect of copper ion and the similar structure of dibenzofurans for PCDFs, the additive effect to form PCDD/Fs is obvious. To add 10 wt % copper chloride, zinc chloride and iron chloride onto the fly ash medium, the experimental results showed the formation of PCDD/Fs was intensively increased by copper chloride. The results also showed that PCDD/Fs concentration of the copper chloride addition case was 4-fold higher than the copper oxide addition. The enhance activity of chlorine atom is higher than the oxygen atom during the formation of PCDD/Fs. To replace the role of the particulate active carbon (PAC) in the fly ash medium to simulate the reformation effect of PCDD/Fs, the pure silica was added to the fly ash matrix. The experimental results showed that silica has minor restrain effect on PCDD/Fs formation, rather than the enhance reformation of the PAC. It suggests the structure and the component of bag filter ash is a complex agent to form PCDD/Fs. Comparison between the PCDD/Fs concentrations and the toxic equivalence quantity (TEQ) indicators in fly ash medium, the principal component analysis (PCA) was conducted. Results show the PCDFs congeners and the lower-chlorinated PCDDs congeners onto the fly ashes from different air pollution control devices (APCD) are more positive related to the TEQ value of PCDD/Fs (R2 > 0.95). In addition, the TEQ of PCDD/Fs onto the fly ash is closely related to the chlorine contents and the BET surface area. The carbon contents may play a minor role relatively compare to the chlorine on the PCDD/Fs formation. The ratio of PCDDs/PCDFs is subject to the temperature range, the chlorination level and the other operation parameters, based on the future investigation to clarify.
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Wang, Po-Jen, i 王柏人. "The source/receptor relationship of PCDD/PCDFs identified by a trajectory model". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/45417259595937860757.
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碩士中興大學
環境工程學系所
95
The Nantou County locates on the eastern site of Taichung city and on the western site of Central Mountain Range. Thus, it is easily to accumulate dioxin in Nantou with the air parcel transferred from western sources. Additionally, several incinerators have already operated in west Taiwan recently, and these also are important dioxins sources. For understanding dioxins characters and sources in the Nantou County, this study analyzes impact range and dioxins characters of near incinerators by measurement and GTx modeling. We considered eight major categories of PCDD/Fs emission sources and three different locations, to cover a wide range of sourcecharacteristic, PCDD/Fs congener profiles, meteorological conditions and terrain configurations. The atmospheric dioxins concentrations in suburban site, traffic arteries site and background station were 0.11, 0.17 and 0.0095 pg I-TEQ/m3, respectively. Moreover, the dioxins concentrations of the grass cut frequently were 0.18, 0.9 and 0.15 pg WHO-TEQ/g, and the dioxins concentrations of the grass cut ifnfrequently were 0.33, 1.5 and 0.13 pg WHO-TEQ/g with a moisture content of 12 %. The characteristic index and model simulations could be founded that suburban site was not only impacted by incinerators, electric arc furnaces and traffic source, but also impacted by copper and aluminum smelters. For traffic arteries station, the main sources were metropolitan solids wastes incinerators, medical wastes incinerators, sinter plants, electric arc furnaces, copper smelters, diesel-fueled vehicles and unleaded gas-fueled vehicles. The model also showed that pollutants were easily transferred into Chushan in north and northeast wind system. Therefore, the north wind system would facilitate the dioxins transporting into Chushan and Shuili, and leaded the dioxins concentrations increasing. This study showed that using the GTx model, atmospheric monitoring data, the pasture examination data and PCDD/Fs congener profiles can explicitly understand the relationship of PCDD/Fs between the source and the receptor.
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Kuo, Fan-Leng, i 郭凡稜. "Gas/Particle Phase Partitions and Size Distributions of PCDD/Fs in Atmosphere". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/79763682343128945923.
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碩士國立成功大學
環境工程學系碩博士班
95
In order to investigate K and R municipal solid waste incinerators (MSWIs) PCDD/Fs of flue gas effect on the surrounding environment. This research focus on K and R MSWIs`s ambient air, Gas/Particle Partitions and Size Distributions of PCDD/Fs. The results are as follows: K MSWI average concentration in ambient air of PCDD/Fs is 0.0749 pg I-TEQ/Nm3; and R MSWI is 0.0727 pg I-TEQ/Nm3. K MSWI Gas/Particle Partitions of PCDD/Fs average concentration is 0.0358 and 0.0283 pg I-TEQ/Nm3; R MSWI is 0.0315 and 0.0195 pg I-TEQ/Nm3. K MSWI Gas/Particle Partitions simulation model of PCDD/Fs average concentration is 0.0405 and 0.034 pg I-TEQ/Nm3; R MSWI is 0.042 and 0.0305 pg I-TEQ/Nm3. To compare surveying and simulation value, that can get the sampling and analysis of Artifact. In MSWI, the size distributions of total particle mass is showed of two peaks, the total particle mass range 3.2~36.5 and 0.52~1.8 μm; the total PCDD/Fs and total I-TQE PCDD/Fs are showed of one peak, the total PCDD/Fs and total I-TQE PCDD/Fs range 0.31~1.0 μm. In MSWI, the cumulative percentage of the total particle mass, total PCDD/Fs and total I-TQE PCDD/Fs, the average MMD are 5.77, 0.77 and 0.78 μm. In MSWI, the average MMDo andδg,o of the total particle mass, total PCDD/Fs and total I-TQE PCDD/Fs, the value are (5.77, 0.77 and 0.71) and (5.17, 2.68 and 2.32) μm；the average MMDf and δg,f are (0.98, 0.62 and 0.59) and (1.91, 2.04 and 1.98) μm；the average MMDc and δg,c are (12.78, 7.44 and 8.74) and (2.72, 2.75 and 2.63) μm. In all of sampling site, the total PCDD/Fs of MMDo value are less than total particle mass of MMDo value. According to the total particle mass and the total PCDD/Fs of theδg,o, it indicates that the distribution range of small particles is larger than the coarse particles. And the range of particle distribution is quite large in atmosphere. Small particle has higher PCDD/Fs concentration than that of larger particle. It could be due to the small particle has larger surface and adsorb more PCDD/Fs on it.
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Hung, Chao-Chin, i 洪朝卿. "Evaluation of the Emission Characteristics of PCDD/Fs from a Sludge Incinerato". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/14219362915975025943.
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碩士國立中央大學
環境工程研究所碩士在職專班
93
Evaluation of the dioxin removal efficiencies of the air pollution control devices (APCDs) at existing industrial sludge incinerator (ISI) in Taiwan is conducted via stack sampling and analysis in this study. The ISI investigated (capacity: 12 tons/day) is equipped with venturi scrubber followed by bag filter (BF). The PCDD/F concentrations measured at venturi scrubber inlet is 0.046 ng-I-TEQ/Nm3 which is lower than that measured at stack (0.321 ng-I-TEQ/Nm3). The results indicate that PCDF concentration is much higher than PCDD measured in flue gas of BF inlet and outlet in the ISI investigated. The flue gas is quenched by venturi scrubber, with the temperature being decreased from 440°C to 173°C. Therefore, the PCDD/F concentration measured at stack gas is significant higher than that measured at BF inlet because the operating temperature of the APCD falls into the temperature window of de novo synthesis (200~350°C). Besides, the results of vapor/solid-phase PCDD/F sampling also indicate that the about 50% PCDD/F congeners exist in solid phase. Hence, the removal efficiency of particle and solid-phase PCDD/F achieved with BF in the ISI investigated should be improved to further reduce its PCDD/Fs emissions. Overall, this study preliminary evaluates the PCDD/F concentration and congener distribution in flue gas of an existing ISI. The results of this study provide important references for the industry in terms of design and operation of ISIs.
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Hung, Pao-Chen, i 洪保鎮. "Characteristics of PCDD/F removal from fly ash and soil via pyrolysis". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/09878797004934978772.
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博士國立中央大學
環境工程研究所
102
Pyrolysis with oxygen-lack condition is applied to remove PCDD/Fs from the fly ash of a municipal waste incinerator (MWI) and contaminated soil of the pentachlorophenol factory in this study. PCDD/F concentration of the raw fly ash (3.54 ng-TEQ/g) is significantly lower than that of the contaminated soil (>114 ng-TEQ/g). Regarding TEQ distribution of PCDD/F congeners, 2,3,4,7,8-PeCDF and OCDD/F are the main toxic contributors of the fly ash and the contaminated soil, respectively. The results obtained with the laboratory-scale batch-type system indicate that influence of temperature is more important than reaction time. For the fly ash, residual concentration of PCDD/Fs in treated ash is efficiently reduced to lower than 1.0 ng-TEQ/g with pyrolysis temperature of 300oC and reaction time of 2 hours. For the contaminated soil, the operating temperature higher than 600oC is needed to ensure that residual PCDD/F concentration in remediated soil is lower than the limit with reaction time of 30 min. because PCDD/F concentration in the contaminated soil is significantly higher than that in the fly ash. Significant dechlorination of PCDD/Fs is significantly found in pyrolysis system. TEQ removal efficiency of PCDD/Fs may be significantly decreased due to formation of low chlorinated congeners. Formation of 2,3,7,8-TCDD, the most toxic PCDD/F congener, is found with specific operating parameters and accumulation of HxCDD/Fs due to dechlorination of highly chlorinated congeners is also found. Regarding the continuous pyrolysis system (CPS), the operating parameters to ensure that residual PCDD/F concentrations can meet the standard are significantly different between the fly ash and the contaminated soil. For fly ash, operating the CPS at a temperature of 350oC and retention time of ≥20 min. is feasible, but temperature ≥600oC and retention time ≥33 min. are needed for effective remediation of contaminated soil. Formation of 2,3,7,8-TCDD is still found, resulting in relatively lower TEQ removal efficiency compared with mass removal efficiency. Nevertheles, PCDD/F concentration in the exhaust of CPS is significantly higher than the emission limit of Taiwan even though less than 0.05% of PCDD/Fs input rate is desorbed. For better control pollutant emission, an air pollution control process consisting of baghouse, quench tower and multi-layer activated carbon (AC) bed is installed for the removal of particulate matter, PCDD/Fs, pentachlorophenol (PCP) and mercury. Firstly, particulate matter (PM) is efficiently filtrated by baghouse and the PM concentration at the outlet of baghouse is lower than 3 mg/Nm3. However, removal efficiencies of PCDD/Fs, PCP and mercury achieved with baghouse are relative low (≤4.5%) due to high temperature of exhaust in the baghouse. As flue gas passes through the quench tower, temperature is rapidly decreased. Water vapor and elementary mercury are effectively condensed and collected. Removal efficiencies of three pollutants achieved with quench tower are higher than 75%, but pollutant concentrations are still higher than emission limits. Therefore, multi-layer AC bed is essential to adsorb gaseous pollutants to make sure the emission of PCDD/Fs, PCP and mercury achieved with three-layer AC bed are lower than the regulatory limits. Overall, a continuous pyrolysis system with effective air pollution control process is developed in this study and experimental results indicate that PCDD/Fs can be efficiently removed from fly ash, contaminated soil and exhaust of CPS.
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Cater, Shari. "Historical trends of polychlorinated dibenzo-p-dioxins and dibenzofurans in fish and sediment associated with two bleached kraft pulp mills in northern Ontario". Thesis, 2013. http://hdl.handle.net/10012/8078.
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In the early 1990s polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) contamination of fish was widely associated with bleached kraft pulp mills. Regulations were put into place in Canada and elsewhere to reduce or eliminate the presence of these chemicals in pulp mill effluents. The industry quickly introduced treatment and process changes such as elemental (ECF) and total chlorine free (TCF) bleaching, which resulted in dramatically reduced PCDD/F concentrations in pulp mill effluents. However, PCDD/Fs may remain a concern for the receiving environment near bleached kraft pulp mills due to their tendency to persist in sediments and bioaccumulate in aquatic biota.
Several studies conducted in the early 1990s reported significantly elevated levels of PCDD/Fs in white sucker (Catostomus commersoni) exposed to bleached kraft mill effluent (BKME). Particularly high concentrations were observed in the receiving environment of two mills in northern Ontario. The first mill, located in the town of Terrace Bay, discharges effluent into Jackfish Bay, Lake Superior. The second mill is located in Smooth Rock Falls, Ontario and discharges effluent into the Mattagami River where effects have been observed in fish collected downstream of the pulp mill. Over time, both mills have undergone a number of process upgrades, including a transition to 100% chlorine dioxide (ClO2) substitution. In 2006 the Tembec Smooth Rock Falls Pulp and Paper Mill closed permanently, while the mill in Terrace Bay has gone through a number of temporary shutdowns and is currently in the process of transitioning to a dissolving pulp process.
Temporal changes in PCDD/F contamination was examined in white sucker historically exposed to BKME in Jackfish Bay and the Mattagami River, following mill process changes and closures. Historical data was summarized from studies conducted in the 1990s and analyzed along with liver tissue of male white sucker collected from each location in 2011 and 2012. The body burden of each fish was analysed using Toxic Equivalency (TEQ) calculations to account for concentration and relative toxicity of 2,3,7,8??? substituted PCDD/F congeners. At Jackfish Bay, concentrations of PCDD/Fs in surface sediment and dated sediment cores were used to document the spatial and temporal pattern of PCDD/F contamination in relation to historical process upgrades and operational changes at the mill.
PCDD/Fs measured in white sucker liver samples collected from Jackfish Bay during gonadal recrudescence in the fall illustrate a decrease in mean TEQ from 74.2 ?? 20.9 pg???g-1 in 1991 to 3.34 ?? 2.05 pg???g-1 in 2012. These values were slightly elevated compared to the remote reference location at Mountain Bay, Lake Superior, which exhibited a mean TEQ of 1.88 ?? 0.45 pg???g-1 and 1.06 ?? 0.69 pg???g-1 in white sucker collected in fall 2011 and 2012, respectively. Although below consumption guidelines, trace levels of PCDD/Fs persist in fish collected from Jackfish Bay and these concentrations are suspected to reflect sediment contamination in Moberly Bay (part of Jackfish Bay). A unique PCDD/F contaminant profile, dominated by 2,3,7,8??? tetrachlorodibenzo???p???dioxin (TCDD) and dibenzofuran (TCDF), was observed in white sucker and sediment collected from Jackfish Bay. Analysis of surface sediment collected throughout Jackfish Bay revealed elevated PCDD/F concentrations, compared to reference areas in Lake Superior. TEQ values measured in surface sediment from the depositional areas of Moberly Bay exceeded the Canadian Council of Ministers of the Environment (CCME) guidelines.
In 1991 PCDD/F contamination, reported as mean TEQ, of white sucker collected downstream of the pulp mill outfall in Smooth Rock Falls reached levels of 111 ?? 86.2 pg???g-1. At the time, the mill utilized molecular chlorine (Cl2) in the bleaching sequence and employed primary effluent treatment. A dramatic decline was observed in PCDD/F concentrations of fish collected in 1993 and 1995, corresponding to implementation of 100% ClO2 substitution in the bleaching process. PCDD/F contamination in white sucker collected from the Mattagami River in 2011 and 2012 were similar upstream (0.53???1.49 pg TEQ???g-1) and downstream (0.75???2.87 pg TEQ???g-1) of the historical pulp mill outfall at Smooth Rock Falls, suggesting a return to background condition following the 2006 mill closure. Levels of 2,3,7,8???TCDD and 2,3,7,8???TCDF in liver tissue of fish collected downstream declined drastically compared to concentrations measured in 1991. The PCDD/F congener profile observed in white sucker downstream in 2011 and 2012 was more similar to fish collected from the reference site upstream than exposed fish collected in 1991. No sediment depositional areas suitable for taking a core sample were found on the river downstream of Smooth Rock Falls due to the nature of the system.
This study supports the conclusion that particulate (POM) and dissolved organic matter (DOM) from continuous inputs of effluent were likely the primary source of PCDD/Fs to fish in these receiving environments, with only a small contribution from surface sediment. Results indicate a decreasing trend in PCDD/F contamination of white sucker historically exposed to bleached kraft pulp mill effluent in the receiving environments of Jackfish Bay and the Mattagami River, consistent with mill process upgrades to eliminate the use of elemental chlorine from the bleaching sequence. Current levels of PCDD/Fs measured in white sucker collected from these locations suggest a return to background condition.