Dissertations / Theses on the topic 'Polychlorinated dibenzofurans'
To see the other types of publications on this topic, follow the link: Polychlorinated dibenzofurans.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Polychlorinated dibenzofurans.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Akki, Umesh. "Gas phase formation pathways and mechanisms of polychlorinated dibenzo-p-dioxins and dibenzofurans." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/23157.
Full text
2
Gaus, Caroline. "Dioxins in the marine environment sources, pathways, and fate of polychlorinated dibenzo-p-dioxins and dibenzofurans in Queensland, Australia /." Connect to this title online, 2002. http://bibpurl.oclc.org/web/9765.
Full text
3
Kim, Do Hyong. "Formation of Aromatic Compounds by Cyclopentadiene Moieties in Combustion Processes." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7241.
Full textAbstract:
Polycyclic aromatic hydrocarbon (PAH) formation and growth from cyclopentadiene (CPD) moieties have been investigated using a laminar flow reactor and molecular modeling. The resonance-stabilized cyclopentadienyl radical is readily formed in flames and can participate in PAH growth to soot by reaction with the ??onds of aromatic species. Both CPD pyrolysis and computational results indicate that formation of indene and benzene is favored at low temperatures (below 750oC) and formation of naphthalene is favored at high temperatures. Reaction pathways from CPD have further been extended to PAH formation from the reaction of CPD and aromatic compounds with different types of ??onds. Results indicate that, while the major products from the pyrolysis of CPD, acenaphthylene, styrene and phenanthrene mixtures are from the reaction of CPD to itself rather than to these aromatic compounds with different ??onds, CPD does add to these compounds to produce larger PAH.
Polychlorinated naphthalene (PCN) formation from chlorinated phenols has also been studied. In combustion exhaust gas, chlorinated phenols can produce dioxin as well as PCNs. PCN and polychlorinated dibenzofuran (PCDF) congener product distributions were consistent with proposed pathways involving phenoxy radical coupling at unchlorinated ortho-carbon sites. Tautomerization of the phenoxy radical coupling and subsequent fusion via H2O loss results in PCDF formation. Competing with this reaction pathway, CO elimination and subsequent fusion via hydrogen and/or chlorine loss was found to produce PCNs. PCDF isomer distributions were found to be weakly dependent to temperature, whereas PCN isomer distributions were found to be more temperature sensitive with selectivity to particular isomers decreasing with increasing temperature.
Results of this research contribute to a better understanding of chemical mechanisms involved in the formation of toxic byproducts and soot in combustion systems.
4
Klees, Marcel [Verfasser], and Torsten Claus [Akademischer Betreuer] Schmidt. "Evaluation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans in street dust and wipe samples / Marcel Klees. Betreuer: Torsten Claus Schmidt." Duisburg, 2015. http://d-nb.info/1075456223/34.
Full text
5
Lohr, Christiane [Verfasser], and Dieter [Akademischer Betreuer] Schrenk. "Effects of Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Polychlorinated Biphenyls in Human Liver Cell Models (in vitro) and in Mice (in vivo) / Christiane Lohr. Betreuer: Dieter Schrenk." Kaiserslautern : Technische Universität Kaiserslautern, 2013. http://d-nb.info/1045604054/34.
Full text
6
Mader, Brian T. "Gas/solid and gas/particle partitioning of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polycyclic aromatic hydrocarbons to filter surfaces and ambient atmospheric particulate material /." Full text open access at:, 2000. http://content.ohsu.edu/u?/etd,193.
Full text
7
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.
Full textAbstract:
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.
8
Yang, Yun. "Temperature dependent PCDD/PCDF product distributions from phenols." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/20182.
Full text
9
Gaus, Caroline, and 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.
Full textAbstract:
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.
10
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.
Full textAbstract:
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
11
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.
Full text
12
Prange, Joelle, and n/a. "Origin of Dioxins in Queensland: Investigations into the Distribution and Sources of Polychlorinated Dibenzo-P-Dioxins in the Queensland Terrestrial Environment." Griffith University. School of Public Health, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040615.161651.
Full textAbstract:
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are persistent organic pollutants of global concern as they are persistent, toxic and can biomagnify through the food chain. PCDD/Fs are generally regarded as trace contaminants in a number of chemical products and they are formed as by-products from various industrial, chemical and combustion processes. The pollution with PCDD/Fs occurs with the release of these chemicals into the environment, resulting in the contamination of various compartments including; air, soil, sediment and biota. Studies that have investigated the distribution of PCDD/Fs in the environment suggest that the highest concentrations of these pollutants are found in locations with a history of industrial or chemical PCDD/F sources. Queensland is the north-eastern state of Australia. Queensland has a low population density, few industrial activities and is considered predominantly rural. Therefore it was somewhat surprising that elevated concentrations of PCDD/Fs (in particular the higher chlorinated PCDDs) have been observed in soil and sediments samples collected from various locations along the Queensland coast. The concentrations of PCDDs in Queensland samples were comparable to or higher than concentrations in similar matrices from highly polluted regions elsewhere. To investigate the origin of PCDDs in Queensland, the geographical distribution of PCDD/Fs in topsoil was investigated in the coastal and inland environments to provide information on the potential sources and to estimate the extent of the PCDD contamination. Distinct east-west gradients were detected in topsoil collected from bushland areas across the state with elevated PCDD concentrations confined to the coastal region. Within the coastal region, the contamination could not be associated with specific land uses. In fact, the PCDD/F congener profile was similar in the majority of samples from the coastal region, with a dominance of the higher chlorinated PCDDs (in particular OCDD), whereas PCDFs were low or below the limit of detection. The similarity in the PCDD/F congener profiles in the soils along the coastal region indicated that a source of PCDDs of similar origin has resulted in the contamination of soil extending more than 3000 km and estimations suggest that more than 50 tonnes of OCDD is stored in the topsoil of Queensland.s coastal region. Investigation into the vertical distribution of PCDDs in Queensland coastal soils revealed elevated concentrations of PCDDs, (in particular OCDD) in soils to at least 3.5 m. These results indicated that the extent of the PCDD contamination is significantly greater than anticipated and it was estimated that there is in the order of 3 000 tonnes of OCDD stored in Queensland's coastal soils. The specific PCDD/F congener profile in Queensland coastal soils is unlike known PCDD/F source profiles which led to the suggestion that some yet unidentified formation mechanism may have resulted in the contamination. Potential natural sources of PCDD/Fs, including forest fires, geogenic and biogenic processes were assessed as possible origins for the PCDD contamination in Queensland. Elevated concentrations of PCDDs were detected in the atmosphere during a 'prescribed burn'. This study demonstrated that although forest fires influence atmospheric PCDD/F concentrations substantially, forest fires are not the source of PCDDs in Queensland; rather they are an important mechanism for the redistribution of PCDDs and may have attributed to the widespread PCDD contamination. In this study geological materials (oil shale and kaolin) were analysed as a proxy to assess a geogenic origin of PCDDs. Elevated concentrations of PCDDs were observed in the kaolin samples, however similar and higher concentrations were detected in surface and sub-surface soils, suggesting that specific geogenic formation processes investigated are not the source of PCDDs in Queensland. A preliminary indication for a biogenic origin of PCDDs was identified during the anaerobic incubation of sugarcane irrigation sediments. An increase in the concentration of OCDD in the anaerobic treatment, compared to the control was observed after incubation for 90 days. In these same experiments, a dechlorination of OCDD to lower chlorinated (1,4,6,9-substituted) PCDDs was also observed. Similar transformation processes were observed in other anaerobic environments in Queensland, which led to the suggestion that a biogenic formation of PCDDs (possibly from a precursor) may be responsible for the origin of PCDDs in Queensland.
13
Prange, Joelle. "Origin of Dioxins in Queensland: Investigations into the Distribution and Sources of Polychlorinated Dibenzo-P-Dioxins in the Queensland Terrestrial Environment." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/367289.
Full textAbstract:
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are persistent organic pollutants of global concern as they are persistent, toxic and can biomagnify through the food chain. PCDD/Fs are generally regarded as trace contaminants in a number of chemical products and they are formed as by-products from various industrial, chemical and combustion processes. The pollution with PCDD/Fs occurs with the release of these chemicals into the environment, resulting in the contamination of various compartments including; air, soil, sediment and biota. Studies that have investigated the distribution of PCDD/Fs in the environment suggest that the highest concentrations of these pollutants are found in locations with a history of industrial or chemical PCDD/F sources. Queensland is the north-eastern state of Australia. Queensland has a low population density, few industrial activities and is considered predominantly rural. Therefore it was somewhat surprising that elevated concentrations of PCDD/Fs (in particular the higher chlorinated PCDDs) have been observed in soil and sediments samples collected from various locations along the Queensland coast. The concentrations of PCDDs in Queensland samples were comparable to or higher than concentrations in similar matrices from highly polluted regions elsewhere. To investigate the origin of PCDDs in Queensland, the geographical distribution of PCDD/Fs in topsoil was investigated in the coastal and inland environments to provide information on the potential sources and to estimate the extent of the PCDD contamination. Distinct east-west gradients were detected in topsoil collected from bushland areas across the state with elevated PCDD concentrations confined to the coastal region. Within the coastal region, the contamination could not be associated with specific land uses. In fact, the PCDD/F congener profile was similar in the majority of samples from the coastal region, with a dominance of the higher chlorinated PCDDs (in particular OCDD), whereas PCDFs were low or below the limit of detection. The similarity in the PCDD/F congener profiles in the soils along the coastal region indicated that a source of PCDDs of similar origin has resulted in the contamination of soil extending more than 3000 km and estimations suggest that more than 50 tonnes of OCDD is stored in the topsoil of Queensland.s coastal region. Investigation into the vertical distribution of PCDDs in Queensland coastal soils revealed elevated concentrations of PCDDs, (in particular OCDD) in soils to at least 3.5 m. These results indicated that the extent of the PCDD contamination is significantly greater than anticipated and it was estimated that there is in the order of 3 000 tonnes of OCDD stored in Queensland.s coastal soils. The specific PCDD/F congener profile in Queensland coastal soils is unlike known PCDD/F source profiles which led to the suggestion that some yet unidentified formation mechanism may have resulted in the contamination. Potential natural sources of PCDD/Fs, including forest fires, geogenic and biogenic processes were assessed as possible origins for the PCDD contamination in Queensland. Elevated concentrations of PCDDs were detected in the atmosphere during a 'prescribed burn'. This study demonstrated that although forest fires influence atmospheric PCDD/F concentrations substantially, forest fires are not the source of PCDDs in Queensland; rather they are an important mechanism for the redistribution of PCDDs and may have attributed to the widespread PCDD contamination. In this study geological materials (oil shale and kaolin) were analysed as a proxy to assess a geogenic origin of PCDDs. Elevated concentrations of PCDDs were observed in the kaolin samples, however similar and higher concentrations were detected in surface and sub-surface soils, suggesting that specific geogenic formation processes investigated are not the source of PCDDs in Queensland. A preliminary indication for a biogenic origin of PCDDs was identified during the anaerobic incubation of sugarcane irrigation sediments. An increase in the concentration of OCDD in the anaerobic treatment, compared to the control was observed after incubation for 90 days. In these same experiments, a dechlorination of OCDD to lower chlorinated (1,4,6,9-substituted) PCDDs was also observed. Similar transformation processes were observed in other anaerobic environments in Queensland, which led to the suggestion that a biogenic formation of PCDDs (possibly from a precursor) may be responsible for the origin of PCDDs in Queensland.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Public Health
Full Text
14
Hassanin, Ashraf Mohamed Sami. "Sources and environmental transfers of polychlorinated dibezo -p- dioxins, dibenzofurans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) and their distribution in the terrestrial environment." Thesis, Lancaster University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431468.
Full text
15
Josefsson, Sarah. "Fate and transport of POPs in the aquatic environment : with focus on contaminated sediments." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-42107.
Full textAbstract:
Persistent organic pollutants (POPs) are hydrophobic substances that readily sorb to organic matter in particles and colloids instead of being freely dissolved in the water phase. This sorption affects the bioavailability and environmental transport of the POPs. The major part of this thesis concerns the role of sediments as secondary sources of POPs. As the primary emissions decrease, contaminated sediments where POPs have accumulated can become the main source of contamination. If the contaminated sediment by time becomes covered with cleaner layers, the POPs are buried and no longer in contact with the aquatic environment. Experiments in this thesis showed, however, that new invading species can alter the sediment-water dynamics as a result of their bioturbation, i.e. mixing of sediment particles and pore-water. Marenzelleria spp., invading species in the Baltic Sea that burrow deeper than native species, were found to increase the remobilization of buried contaminants. The sediment-to-water flux was inversely related to the burial depth (2-10 cm) of the POP congeners (polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers) and also inversely related to the hydrophobicity of the congener. The flux was therefore most pronounced for less hydrophobic contaminants, which was linked to the bioirrigating behaviour of these species. Marenzelleria spp. also accumulated the buried POPs and increased concentrations in surface sediment. Contaminants previously considered buried at a ’safe’ depth can thus be remobilized as a result of the invasion of Marenzelleria spp. in the Baltic Sea. One method to decrease the remobilization of contaminants from sediments is ’capping’, i.e. a layer of clean material is placed as a cap on the sediment. By amending the cap with active materials, which sequester the POPs and decrease their availability, thinner layers can be used (’active capping’ or ’thin-layer capping’). Results from an experiment with thin-layer capping using different active materials (activated carbon (AC) and kraft lignin) showed that both the sediment-to-water flux and the bioaccumulation by benthic species of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), hexachlorobenzene (HCB) and octachlorostyrene (OCS) decreased with increased thickness of the cap layer (0.5-5 cm). Amendments with active materials further increased the cap efficiency. AC was more efficient than kraft lignin, and a 3 cm cap with 3.3% AC reduced the flux and bioaccumulation with ~90%. The reduction of the sediment-to-water flux was inversely related to the hydrophobicity of the POP, and reductions in the flux had similar magnitudes as reductions in the concentration in deep-burrowing polychaetes, demonstrating the importance of bioturbation for sediment-to-water transport. In a one-year study on the levels of PCDD/Fs, PCBs, and HCB in a coastal area of the Baltic Sea, the correlations between the POP levels and the levels of particles and organic carbon in the water were found to differ for POPs of different structure and hydrophobicity. The levels of PCDD/Fs decreased to one third in May, which could be related to the increased sedimentation, i.e. water-to-sediment transport, during spring bloom.
16
Öberg, Mattias U. L. "Health risk assessment of dioxin-like compounds in complex samples /." Stockholm : Karolinska inst, 2003. http://diss.kib.ki.se/2003/91-7349-692-8.
Full text
17
Leeman, Whitney Renae. "Historic polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations in Riverside, California : evidence of a diffuse vehicular source /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
Full text
18
Lundgren, Kjell. "Properties and analysis of dioxin-like compounds in marine samples from Sweden." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-24.
Full textAbstract:
Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) have been assigned toxic equivalency factors (TEFs). These compounds are today routinely analysed with sophisticated analytical techniques. In a near future, there might be other dioxinlike compounds such as polychlorinated naphthalenes (PCNs), alkyl-polychlorodibenzofurans (R-PCDFs), and polychlorinated dibenzothiophenes (PCDTs) added to this list of toxic dioxin-like compounds. It is therefore important to have a readiness to analyse these new compounds in environmental samples. In this study, a multi-residue non-destructive analytical method for the analyses of these planar dioxin-like compound classes was developed. The use of HPLC PX-21 carbon column fractionation enabled the separation of interfering PCBs from coplanar PCBs and other planar dioxin-like compounds of interest. The obtained planar fraction containing the dioxin-like compounds was analysed using high-resolution GC-MS. Levels of PCNs in surface sediments and settling particulate matter in the northern Baltic Sea were determined. The concentrations of PCNs in background surface sediments were approximately 1 ng/g dw and the estimated PCN fluxes were similar to the pre-industrial levels determined in Europe. The PCN congener patterns in the surface sediments suggest that the PCNs deposited in the Baltic Sea originate from similar sources. Bioaccumulation of PCNs in a benthic food chain (sediment, amphipod, isopod, and four-horned sculpin) from the Gulf of Bothnia was studied. The results indicated that only a few PCN congeners biomagnified. The highest biomagnification factors (BMFs) were found for 2,3,6,7-substituted congeners and those lacking adjacent hydrogen-substituted carbon atoms. The calculated biota to sediment accumulation factors (BSAFs) showed that the tetra- and penta- CNs exhibited BSAF values higher than one, while BSAFs for the more chlorinated PCNs were less than one. A general difference between the northern and southern parts of the Gulf of Bothnia could be seen in the samples, with the lowest PCN and total PCB concentrations being found in the north and the highest in the south. This gradient is related to distance from the more industrialised and populated regions in the southern parts of Sweden and Finland, and central Europe. Analysis of R-PCDFs in crustacean samples from the Swedish west coast was performed using HRGC-MS/MS. The ΣR-PCDFs in these samples were present at concentrations up to 10 times higher than the ΣPCDFs. The relatively high concentrations of R-PCDFs in the crab samples demonstrate that these compounds bioaccumulate. The fate of a pollutant in the environment and the toxicity of a compound are governed by its physicochemical properties. The information found in a data set of properties can predict a compound’s mode of action. The following physicochemical properties for 87 PCDFs were measured: ultra-violetadsorption, relative retention times on two common gas chromatographic stationary phases, and relative mass spectrometric response factors using EI- and NCI- modes.
19
Assefa, Anteneh. "Tracing and apportioning sources of dioxins using multivariate pattern recognition techniques." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-102877.
Full textAbstract:
High levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in edible fish in the Baltic Sea have raised health concerns in the Baltic region and the rest of Europe. Thus, there are urgent needs to characterize sources in order to formulate effective mitigation strategies. The aim of this thesis is to contribute to a better understanding of past and present sources of PCDD/Fs in the Baltic Sea environment by exploring chemical fingerprints in sediments, air, and biota. The spatial and temporal patterns of PCDD/F distributions in the Baltic Sea during the 20th century were studied in Swedish coastal and offshore sediment cores. The results showed that PCDD/F levels peaked in 1975 (± 7 years) in coastal and 1991 (± 5 years) in offshore areas. The time trends of PCDD/Fs in the sediment cores also showed that environmental half-lives of these pollutants have been shorter in coastal than in offshore areas (15 ± 5 and 29 ± 14 years, respectively). Consequently, there have been remarkable recoveries in coastal areas, but slower recovery in offshore areas with 81 ± 12% and 38 ± 11% reductions from peak levels, respectively. Source-to-receptor multivariate modeling by Positive Matrix Factorization (PMF) showed that six types of PCDD/F sources are and have been important for the Baltic Sea environment: PCDD/Fs related to i) atmospheric background, ii) thermal processes, iii) manufacture and use of tetra-chlorophenol (TCP) and iv) penta-chlorophenol (PCP), v) industrial use of elementary chlo- rine and the chloralkali-process (Chl), and vi) hexa-CDD sources. The results showed that diffuse sources (i and ii) have consistently contributed >80% of the total amounts in the Southern Baltic Sea. In the Northern Baltic Sea, where the biota is most heavily contaminated, impacts of local sources (TCP, PCP and Chl) have been higher, contributing ca. 50% of total amounts. Among the six sources, only Thermal and chlorophenols (ii-iv) have had major impacts on biota. The impact of thermal sources has, however, been declining as shown from source apportioned time-trend data of PCDD/Fs in Baltic herring. In contrast, impacts of chlorophenol-associated sources generally increased, remained at steady-state or slowly decreased during 1990-2010, suggesting that these sources have substantially contributed to the persistently high levels of PCDD/Fs in Baltic biota. Atmospheric sources of PCDD/Fs for the Baltic region (Northern Europe) were also investigated, and specifically whether the inclusion of parallel measurements of metals in the analysis of air would help back-tracking sources. PCDD/Fs and metals in high-volume air samples from a rural field station near the shore of the central Baltic Sea were measured. The study focused on the winter season and air from the S and E sectors, as these samples showed elevated levels of PCDD/Fs, particularly PCDFs. Several metals were found to correlate significantly with the PCDFs. The wide range of candidate metals as source markers for PCDD/F emissions, and the lack of an up-to-date extensive compilation of source characteristics for metal emission from vari- ous sources, limited the use of the metals as source markers. The study was not able to pin-point primary PCDD/F sources for Baltic air, but it demonstrated a new promising approach for source tracing of air emissions. The best leads for back-tracking primary sources of atmospheric PCDD/Fs in Baltic air were seasonal trends and PCDD/F congener patterns, pointing at non-industrial related thermal sources related to heating. The non-localized natures of the sources raise challenges for managing the emissions and thus societal efforts are required to better control atmospheric emissions of PCDD/Fs.EcoChange
BalticPOPs
20
Sundqvist, Kristina. "Sources of dioxins and other POPs to the marine environment : Identification and apportionment using pattern analysis and receptor modeling." Doctoral thesis, Umeå universitet, Kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-22266.
Full textAbstract:
In the studies underlying this thesis, various source tracing techniques were applied to environmental samples from the Baltic region. Comprehensive sampling and analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surface sediments in Swedish coastal and offshore areas resulted in a unique data set for this region. Nearly 150 samples of surface sediments were analyzed for all tetra- to octa-chlorinated PCDD/Fs. The levels showed large spatial variability with hotspots in several coastal regions. Neither Sweden nor the EU has introduced guideline values for PCDD/Fs in sediment, but comparisons to available guidelines and quality standards from other countries indicate that large areas of primarily coastal sediments may constitute a risk to marine organisms. Multivariate pattern analysis techniques and receptor models, such as Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF), were used to trace sources. These analyses suggested that three to six source types can explain most of the observed pattern variations found in the sediment samples. Atmospheric deposition was suggested as the most important source to offshore areas, thus confirming earlier estimates. However, spatial differences indicated a larger fraction of local/regional atmospheric sources, characterized by PCDFs, in the south. This was indicated by the identification of several patterns of atmospheric origin. In coastal areas, the influence of direct emission sources was larger, and among these, chlorophenol used for wood preservation and emissions from pulp/paper production and other wood related industry appeared to be most important. The historic emissions connected to processes involving chemical reactions with chlorine (e.g. pulp bleaching) were found to be of less importance except at some coastal sites. The analysis of PCDD/Fs in Baltic herring also revealed spatial variations in the levels and pollution patterns along the coast. The geographical match against areas with elevated sediment levels indicated that transfer from sediments via water to organisms was one possible explanation. Fugacity, a concept used to predict the net transport direction between environmental matrices, was used to explore the gas exchange of hexachlorocyclohexanes (HCHs) and polychlorinated biphenyls (PCBs) between air and water. These estimates suggested that, in the Kattegat Sea, the gaseous exchange of HCHs primarily resulted in net deposition while PCBs were net volatilized under certain environmental conditions. The study also indicated that, while the air concentrations of both PCBs and γ-HCH are mostly dependent upon the origin of the air mass, the fluctuations in α-HCH were primarily influenced by seasonal changes.
21
Walker, Mary Katherine. "Toxicity of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls during salmonid early development." 1991. http://catalog.hathitrust.org/api/volumes/oclc/25644050.html.
Full text
22
Kao, Yu-Chin, and 高妤秦. "Reproductive effects in women exposed to polychlorinated biphenyls/dibenzofurans." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/39574471840903231440.
Full textAbstract:
碩士國立成功大學
環境醫學研究所
91
Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-furans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) are among the most widespread environment pollutants. These endocrine disrupting chemicals alter sexual maturation and endocrine function in animal studies, but their effects on humans’ reproductive system are not well studied. The purpose of this study was to assess reproductive effects in women exposed to PCBs/PCDFs. In Taiwan in 1979, a severe event of accidental exposure to PCBs/PCDFs due to ingestion of PCBs/PCDFs-contaminated rice-bran oil was reported and called Yucheng (oil-disease). Information on menstrual characteristics, reproductive function, and reproductive history including time to pregnancy were collected retrospectively by a questionnaire interview. A total of 192 Yucheng women and 188 controls matched for sex, age, gender, area of residence and educational level completed the questionnaire interview satisfactorily. Yucheng women exposed to PCBs/PCDFs before puberty had longer days of menstrual flow (5.8 vs. 5.3, p=0.02) and mean menstrual cycle length (30.4 vs. 29.8). Among 135 married Yucheng women and 132 controls, more of the Yucheng women reported having premature birth rate (16.8% vs. 9.3%) and stillbirth rate (57.1% vs. 44.4%). Yucheng women exposed to PCBs/PCDFs before puberty had higher stillbirth rate (6.4% vs. 0%, p=0.05). High level PCBs/PCDFs exposure also had a higher stillbirth rate (13.5% vs. 1.9% vs.2.3%, p=0.003). Waiting time to pregnancy of Yucheng women was longer than controls, and a decrease fecundability ratio was found (fecundability ratio=0.85, 95%CI: 0.73~0.98). Our findings suggest that women exposed to PCBs/PCDFs were affected their reproductive function.
23
CHANG, CHIH-YUAN, and 張志遠. "Treatment of Polychlorinated Dibenzo-p-dioxins/Polychlorinated Dibenzofurans Contaminated Soil by using Thermal Desorption Technology." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/24592647737795006796.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
95
A thermal desorption technoloy was choosen to treat the contaminated soil of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs). The main target of this work was to investigate the effects of heating temperatures on desorption efficiency and the PCDD/F concentrations in the thermal treated soils. Results reveal that the heating temperature is a significant factor that influenced both desorption efficiency and PCDD/F concentrations in the thermal treated soils. When heating temperatures were set at 750°C and 850°C, the desorption efficiency of the total PCDD/Fs in the contaminated soil was more than 99% and the pyrolysis efficiency of total PCDD/Fs was more than 97%. In addition, the total PCDD/Fs I-TEQ concentrations in the two desorbed soils at temperatures of 750°C and 850°C were 0.892 and 1.15 ng I-TEQ/kg, respectively, both were below the soil pollution regulated standard in Taiwan (1000 ng I-TEQ/kg).
24
Zong-SianWu and 吳宗憲. "Characteristics of Polychlorinated Dibenzo-p-dioxins, Dibenzofurans and Polychlorinated Biphenyls in the Atmosphere of Southern Taiwan." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/65723618804809567241.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
100
This study investigates the characteristics of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the atmosphere of southern Taiwan. The ambient air was collected seasonally in four areas including industrial area, urban area A, urban area B as well as rural area to determine the concentrations of PCDD/Fs and PCBs. Gaseous and particulate concentrations were both obtained by measurement and simulation, and dry deposition fluxes and velocities were also developed. PCDD/F, PCB and their I-TEQ concentrations in urban area B were both the highest of all areas in fall and spring, followed by urban area A, industrial area and rural area. All PCB concentrations were higher than PCDD/Fs, but all the I-TEQ concentrations of PCBs were 10 times lower than PCDD/Fs. This result shows that PCDD/Fs dominated the toxicity in the atmosphere. The PCDD/F and PCB congener profiles of four different areas all show that 1,2,3,4,6,7,8-HpCDD, OCDD, 1,2,3,4,6,7,8-HpCDF and OCDF; PCB#77 (4CL), PCB#105 (5CL) and PCB#118 (5CL) were dominant respectively. The particle-phase PCDD/Fs dominated the partition in both measured and simulated data (average of 72.68-75.03%) except the lowly chlorinated congeners (4-5Cl PCDD/Fs). In terms of PCBs, the particle-phase PCBs contributed little in measured data, but the congeners which were highly chlorinated such as PCB#169 (6CL) and PCB#189 (7CL) were dominant in simulated data (average of 65.86-74.15%). The results form PCBs were quite different with PCDD/Fs. Additionally, the artifacts during sampling work due to the adsorption and blow-off mechanism were not fewer enough to neglect. The total dry deposition flux and estimated monthly dry deposition flux of PCDD/Fs in fall were both higher than in spring. It demonstrates that the dry deposition flux of PCDD/Fs decrease as the temperature increase. The trend of PCBs was the same as PCDD/Fs. It might due to the similar physical and chemical properties of PCDD/Fs and PCBs. Moreover, the dry deposition of PCDD/Fs and PCBs were mainly contributed by particle-phase compounds. This is probably due to the significantly higher deposition velocity of particle-phase PCDD/Fs (0.506-0.571 cm/s) and PCBs (2.83-5.49 cm/s) than the gas-phase (0.010 cm/s). Dry deposition velocities of individual congeners increased as the chlorine number increased in both fall and spring, and there was a significant difference between highly and lowly chlorinated congeners (differences of PCDD/Fs and PCBs were 3.9-4.8 and 7.7-9.3 times respectively).
25
Liu, Fang1975. "Microbial dechlorination of polychlorinated dibenzo-p-dioxins and dibenzofurans pathways, kinetics and environmental implications." 2007. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.16730.
Full text
26
Chou, I.-Cheng, and 周宜成. "Assessment of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans Detection by Bioassay." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68505963875309748552.
Full textAbstract:
博士國立成功大學
環境工程學系碩博士班
97
The dioxin-like compounds are one of the most hazardous material groups in the world. Traditional chemical analysis methods (e.g., HRGC/HRMS and HRGC/LRMS) are time-consuming and costly for these compounds. Thus, the major aim of this study is to build a rapid and less-cost bioassay method. The Xenobiotic Detection Systems - chemical activated luciferase gene expression (CALUX) bioassay was thus employed in this study for detecting dioxin-like compunds. The dissertation is mainly concerned with three issues: 1) a review of the bioassay literature; 2) building the bioassay method for detecting dioxin-like compounds in milk and relative quality assurance/ quality control (QA/QC); and 3) discussing the effects of eight metal ions (Hg2+, Ag+, Cu2+, Fe2+, As5+, Cr6+, Cd2+, and Pb2+) on the bioassay method. The results of part one show that the main dioxin bioassay methods are immunoassay, the biological metabolic reaction of dioxins (including the DNA recombinant cell), and biosensors. The methods that based on the first and second principles have been accepted as standard analysis methods by U.S. EPA, and thus they are stable and accurate enough for use with real samples. Although biosensors are not a standard analysis method used by the U.S. EPA, however, they are important because they offer real-time on-site monitoring. The results of part two show that the analyzed data suggest that the CALUX bioassay criteria have: (1) control chart for quality control (QC) standards within the μ ± 2σ range; and (2) a recovery efficiency (i.e., relative standard deviation (RSD) of 20.7%. This bioassay method was utilized on 28 commercially available pasteurized milk samples, and the results illustrate that CALUX is a powerful approach for screening a large number of such samples. Finally, the results of part three show further study found that the bioassay cell-line was sensitive to particular metals, which might be a potential interfering factor. A two-level factorial-designed experiment was undertaken to identify the statistically significant factors from eight metal ions (Hg2+, Ag+, Cu2+, Fe2+, As5+, Cr6+, Cd2+, and Pb2+), and the results revealed that Hg2+, Cu2+, and Cr6+ had significant effects on the luciferase activity expression of the H1L6.1 cells. In addition, the correlation between luciferase activity and the relative survival ratio of H1L6.1 cells with metal concentrations was not comparable. This reveals the inhibiting effect of metals on luciferase activity may not only be caused by the reduction of H1L6.1 cells, but may also be caused by the other mechanisms, such as a reduction of luciferase enzyme production or the inhibiting effect of metal ions on CYP1A activation. The study illustrates that the bioassay method it presents is a rapid and less-costly approach for detecting dioxin-like compounds. However, potential interference factors, (specifically heavy metal ions) for the bioassay should be eliminated in the pretreatment process to maintain the stability of analysis. The proposed bioassay method with metabolite assay could be emplyeed in risk assessment by using the physiologically based pharmacokinetic model; in addition, the biosensors could be used as an on-site monitoring tool when combined with portable instruments.
27
Chang, Yoon-seok. "The synthesis and electron capture negative ion mass spectrometry of polychlorinated diphenyl ethers and dibenzofurans." Thesis, 1990. http://hdl.handle.net/1957/36992.
Full text
28
Hung-ChiJiang and 江泓機. "Formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans during Thermal Treatment Process of Waste Incineration Fly Ash." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/25555256088147050541.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
98
The objectives of the study were to know the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from waste incineration fly ash after thermal treatment, and the effect of temperature gradient and CaO of PCDD/Fs formation. The results indicated that the total PCDD/Fs content in raw fly ash was 6.20 ng I-TEQ/g which was close to treated fly ash range from 4.33 to 7.99 ng I-TEQ/g at low temperature (50-250℃). However, the PCDD/Fs contents (371 to 741 ng I-TEQ/g) in treated fly ash was dramatically increase at the temperature higher then 300℃. In addition, mixing CaO with raw fly ash, the total PCDD/Fs content was decreased between 59.3 to 360 ng I-TEQ/g, which was a obvious inhibition efficiency. Thus, the CaO really could enhance the inhibition of PCDD/Fs formation during the thermal process.
29
Lo, Chien-Kuang, and 駱黔光. "Characteristics of Polychlorinated Dibenzo-p-Dixoins and Dibenzofurans in the Rural Environment." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/27545721547325428719.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系
94
This study investigated the Dioxin/Furan (PCDD/Fs) concentrations in the vicinity of an incinerator being constructed in Taiwan. Four sampling sites with maximum ground surface concentrations downwind from the incinerator were selected using a dispersion model to collect air, soil, and vegetation samples. The samples were analyzed using high resolution Gas Chromatographer (HP6970) connected with a high resolution Mass Spectrometer (UK). The average PCDD/Fs I-TEQ concentration of air samples was 0.0377 pg I-TEQ/Nm3 (Range: 0.0207–0.0495 pg I-TEQ/Nm3), with the highest and lowest concentrations at Sites A and D, respectively. The average concentration of PCDD/Fs-TEQ in the vegetation samples was 1.49 ng I-TEQ/kg (Range: 0.951–1.97 ng I-TEQ/kg) with the highest and lowest concentrations at Sites C and D, respectively. The variation of vegetation PCDD/Fs concentration was mainly due to the effect of mobile sources. Site C is near a heavily trafficked freeway and a scenic recreation area, whereas Site D is located at a rural area with a low traffic loading. The average PCDD/Fs concentration of soil was 0.880 ng I-TEQ/kg (Range: 0.137–1.92 ng I-TEQ/kg), with the highest and lowest concentrations at Sites C and D, respectively. The variation of soil PCDD/Fs concentration was chiefly because of the weather conditions and stationary/mobile sources. The PCDD/Fs concentrations in the air in the vicinity of L-incinerator were mainly affected by the stationary sources south away from the sampling sites.
30
CHUANG, I.-PING, and 莊懿玶. "Distribution of polychlorinated dibenzo-p-dioxinsand dibenzofurans in municipal solid waste incinerators." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/dqgb8r.
Full textAbstract:
碩士正修科技大學
營建工程研究所
106
This study investigated the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the ashes of different units in three municipal solid waste incinerators (MSWIs). The units of MSWIs included combustion chamber, superheater, economizer, semi-dry scrubber, fabric filter, and ash storage pit. The PCDD/F TEQ contents in the ashes of different units of MSWIs were, in order, fabric filter (3.40 ng I-TEQ/g)> fly-ash storage pit (1.25 ng I-TEQ/g) > economizer (0.459 ng I-TEQ/g) > dry scrubber (0.185 ng I-TEQ/g) > superheater (0.0446 ng I-TEQ/g) > combustion chamber (0.0120 I-TEQ/g). The results were consistent with other studies. Bottom ash and fly ash of the superheaters exhibited lowest PCDD/F contents due to their high operational temperature, which were 903 ℃~950 ℃ and >500 °C, respectively. When the flue gases flew to economizer, which operational temperature (339 °C ~ 396 °C) favored PCDD/F formation, the PCDD/F contents in the fly ashes of the economizer can be found rapidly increased, as reported in the literatures. Then the PCDD/F contents in the fly ashes of semi-dry scrubber decreased due to the spray of hydrated lime (Ca(OH)2). The PCDD/F contents in the fly ashes raised again when the gaseous PCDD/Fs in the flue gas was adsorpted by activated carbon and then collected by fabric filter. From the trends of PCDD/F contents in fly ashes from the three MSWIs, it is obvious that the economizer was the resource of PCDD/Fs in the MSWI. Therefore, reducing the retention time of flue gases within the economizer and increasing the heat exchange efficacy can reduce PCDD/F formation in MSWIs effectively.
31
Yu-JungTseng and 曾鈺容. "Atmospheric Deposition Modeling of Polychlorinated Dibenzo-p-dioxins, Dibenzofurans and Polychlorinated Biphenyls in the Ambient Air of Southern Taiwan." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/fqwuk3.
Full textAbstract:
碩士國立成功大學
環境工程學系
102
Polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are carcinogenic persistent organic compounds (POPs) that can bioaccumulate in the ecosystem, cause endocrines disruption and undergo long range transport in the atmosphere. Atmospheric deposition including those of dry and wet is a primary pathway for the transfer of POPs to terrestrial and aquatic ecosystems. In this study, the characteristics of PCDD/Fs and PCBs in the ambient air of Tainan City were simulated by the PM10 versus PCDD/Fs concentration regression analysis, gas-particle partition modeling, dry deposition and wet deposition simulations. Dry and wet deposition fluxes were obtained from the combination of the PCDD/F and PCB concentrations, meteorological information, dry deposition velocities, and scavenging ratios. The dry deposition fluxes of PCDD/F-TEQ2005 increase with decreasing temperature, while increase with higher degree of chlorine numbers on PCDD/F homologues. However, a wet deposition flux increased with stronger rainfall intensity. From the congener profile of PCDD/F and PCB WHO2005-TEQ total deposition fluxes, 2,3,4,7,8-PeCDF, 2,3,4,6,7,8-HxCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,7,8-PeCDD dominate the deposition fluxes. PCB-126 and PCB169 are two most significant congeners that dominate the PCB WHO2005-TEQ. The simulated results shows that average PCDD/F and PCB dry deposition fluxes during 2012 are 2.23-13.7 pg WHO2005-TEQ/m2-day and 0.131-0.607 pg WHO-TEQ/m2-day, respectively. The average PCDD/F and PCB dry deposition fluxes during 2013 are 2.29-15.7 pg WHO2005-TEQ/m2-day and 0.0975-0.924 pg WHO-TEQ/m2-day, respectively. The minimum simulated value occurred in summer, while the maximum dry deposition fluxes that were 4.35-5.57 times higher than the minimum values occurred in winter. Lower values observed in summer may cause by the atmospheric diffusion of SVOCs and high rainfall intensity. The monthly PCDD/F and PCB wet deposition fluxes during 2012 are in the range of 9.26-265 pg WHO2005-TEQ/m2-month and 0.205-9.38 pg WHO-TEQ/m2-month, respectively. The monthly PCDD/F and PCB wet deposition fluxes during 2013 are 0.152-211 pg WHO2005-TEQ/m2-month and 0.00823-6.84 pg WHO-TEQ/m2-month, respectively. Wet deposition mainly centralized in the high rainfall intensity seasons such as summer. Both dry and wet depositions are dominated by particulate phase. Regarding to the annual PCDD/F and PCB total (dry + wet) WHO2005-TEQ deposition fluxes, dry deposition fluxes accounts for 68.0-73.9%. Among these, PCDD/Fs dominate the total deposition (95.9-96.1%) and PCBs only contribute 3.9-4.1%. The average total PCDD/F and PCB-TEQ2005 deposition (dry + wet) flux in winter season (317-429 pg WHO-TEQ/m2-month) was 1.46-2.63 times of magnitude higher that of in summer season (163-216 pg WHO-TEQ/m2-month). The simulated results of this study combine with the previous measured data provided useful information for the future policy making and further studies. In Taiwan, more measured data associated with dry deposition velocity and wet scavenging is needed for a more precise and complete investigation in the future.
32
Shih, Min-Hua, and 施敏華. "A Study of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans Patternsin Oysters, Milk Fishes, and Porks in Southern Taiwan." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/60424381463999113242.
Full textAbstract:
碩士國立成功大學
化學系碩博士班
94
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are series of chlorinated aromatic homologs which are unwanted by-products generated in the processes of combustions and industrial chemical manufacturing. These compounds are extremely stable and very lipophilic, and PCDD/Fs are both considered to be highly toxic environmental contaminants. PCDD/Fs can be accumulated via the food chain and enter the human body to induce adverse health effects. Among the many PCDD/Fs isomers, there are 17 species of the 2,3,7,8-chloro substituted congeners are regarded as having the most severe toxicity. In this study, the characteristics of the toxic PCDD/Fs in tissues of different animal species are investigated and correlation ship of the results and the environment are also studied. Three animal species in range from the lower to higher levels of the food chain, such as oysters, milk fishes, and porks, were analyzed for the PCDD/Fs. The concentrations of each congener and the PCDD/Fs distribution pattern in these species were closely examined and compared with the findings in various literature. Discussions are focused on the fates of the PCDD/Fs in the animal species as well as in correlating the distribution pattern with the environment. The samples used in this study were collected in southern Taiwan. The official analytical method of Taiwan for dioxins and furans, NIEA M801.11B and the USEPA method 1613B, were employed throughout the entire analytical procedure, including sample preparation and instrument analysis. All quality control and quality assurance procedures were also strictly adhered to as described in the methods. Preparation methods included Soxhlet extraction, lipid elimination, and acidic silica gel/acidic alumina/carbon/celite column clean up procedures, and the final sample extracts were analyzed by utilizing high-resolution gas chromatography/ high-resolution mass spectrometry (HRGC/HRMS). The investigation results indicated that in addition to the total PCDD/Fs concentration, the fraction containing the highly chlorinated PCDD/Fs also showed an increasing trend from oysters, milk fish to pigs. Since porks are higher up the food chain than milk fishes and oysters, they are expected to have a higher accumulation of PCDD/Fs. The analytical data paralleled well with the expectation. However, the highly chlorinated PCDD/Fs have relative low toxicity equivalent factors compared to the less chlorinated congeners; the contribution to the toxicity in the body is less significant. Oysters are a sessile animal species; thus, the PCDD/Fs concentrations and distribution patterns found in the oyster normally reflect the contamination of the farming environment. It was also found that the PCDD/Fs distribution pattern found in the oyster samples is likely affected by the environment of Taiwan.
33
Hung, Chia-Yang, and 洪嘉陽. "Characteristics of Polychlorinated Dibenzo-p-dioxins∕Dibenzofurans in the Leaves of Ficus Species." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/22762049533421139961.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
91
This study investigates the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in leaves of the Ficus species in rural areas, Taiwan. The main objective of this study is to evaluate the transfer of atmospheric compounds into leaves. Additionally, a model to estimate the leaf content is developed and its results compared with the actual leaf content in Ficus species. Furthemore, the total degradation coefficient and half-life of PCDD/Fs in Ficus is estimated. The following conclusions are drawn. 1. The PCDD/Fs concentration in the atmosphere are between 0.129∼1.115 pg/Nm3, the average is 0.493pg/ Nm3.The PCDD/Fs concentrations in the atmosphere in the TD area is from 0.009 to 0.103 I-TEQ-pg/Nm3 with a nean value of 0.033 I-TEQ-pg/ Nm3. 2. The percentage of particle-bound of PCDD/Fs range from 48.9％（2,3,7,8-TCDF） to 96.9％（OCDD）. 3.The maximum pore diameter that allowed suspension particle entering in the leaves of Ficus species is 3.2 μm and the particle-bound of PCDD/Fs with aerodynamic diameter（dae）＜3.2 μm is 92.4％. 4.The PCDD/Fs leaf content in Ficus Species of TD area is form 0.178∼1.861 I-TEQ-pg/g（mean=0.467 I-TEQ-pg/g）. The PCDD/Fs content , adsorbed on the leaves’ surfaces, is from 0.0021 to 0.0084I-TEQ-g/g (mean = 0.0062 pg-I-TEQ/g). 5.The average percentage of PCDD/Fs content absorded in and adsorbed on the surfaces of the leaves of Ficus are 99.07％ and 0.93％,respectively. 6. The result of this study revealed that the primary pathway for PCDD/Fs entering the leaves was by particle phase absorption (86.4%). This result is different from the report by previous study that the gas phase PCDD/Fs was the main pathway entering the leaves. 7. The degradation coefficient ktot（including the photolysis and the biodegradation coefficient）of total PCDDs was determined as 0.0390 day-1 by using pseudo first kinetics：Cr=Cee-ktott, while that of total PCDFs was 0.0603 day-1 and the degradation coefficient of total PCDD/Fs was 0.0499 day-1, respectively. 8.The degradtion half-life of PCDD/Fs, estimated the pseudo first-order rate constant kp for photolysis and kb for biodegradation, were as follows . The half-life time of PCDDs in Ficus leaves is from 327 hours （1,2,3,4,7,8-HxCDD） to 458 hours （OCDD）and the average is 426 hours. The half-life time of PCDFs in Ficus leaves is from 240 hours（1,2,3,7,8,9-HxCDF） to 297 hours（1,2,3,7,8-PeCDF）and the mean half-life of seventeen PCDD/F congeners was 276 hours.
34
Hsieh, Yen-Kung, and 謝炎恭. "Investigation on Polychlorinated Dibenzo-p-dioxins/Dibenzofurans in Ambient Air and Environmental medium." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/78748539997785106157.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
93
The mean PCDD/Fs concentration in 8 ambient air samples in the vicinity of PI municipal solid waste incinerator (MSWI) is 0.069 pg-I-TEQ/Nm3. Compared with ambient air concentration of Japan regulation level (0.6 pg-I-TEQ/Nm3), the ambient air concentration of the PI incinerator is lower than Japanese regulation level. The mean PCDD/Fs composition in vegetation and soil samples in the vicinity of PI MSWI is 2.259 and 1.007 ng-I-TEQ/kg-d.w., respectively. In this study, even the soil from site C, which has the highest PCDD/Fs level, can still be freely utilized (based on the German regulation value). According to the homologue profile of ambient air samples, most sites had profiles similar to those of PI MSWI or mobile sources. By comparing the PCDD/Fs concentration (composition) of maximum ground concentration sampling sites, upwind and downwind sampling sites, it is concluded that the emission of PCDD/Fs from the PI MSWI to its surrounding environment is not significant.
35
Li, Ming-Chieh, and 李銘杰. "Long-Term Health Outcome after Exposure/Prenatal Exposure to Polychlorinated Biphenyls and Dibenzofurans." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/7fqcr2.
Full textAbstract:
博士國立臺灣大學
職業醫學與工業衛生研究所
103
In 1979, there was an outbreak of severe acne, skin pigmentation, and conjunctivitis in central Taiwan. Most of the cases had consumed the same brand of cooking oil, bought at the same stores. The illness, and its relation to cooking oil consumption, resembled a form of polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs) poisoning (called “Yusho,” oil disease in Japanese) that had occurred in western Japan in 1968, and oil and blood samples sent to Tokyo for analysis had high concentrations of PCBs and PCDFs. Yucheng (“oil disease” in Chinese) thus became the second recorded disease outbreak due to rice bran cooking oil contaminated by PCBs/PCDFs during manufacture. Although about 2000 persons registered with health agencies as being exposed after each episode, the exact number of victims is unknown. We followed the exposed persons and compared their cause-specific mortality with that of neighborhood referents 30 years after the accident. Furthermore, we conducted a meta-analysis of Yucheng and Yusho cohorts to reevaluate the effects of PCBs and PCDFs on major causes of mortalities. PCBs have been suggested as neurotoxicants especially when exposed during prenatal and early postnatal periods, and known to cause neurological effects including auditory impairments. Thus we conducted a follow-up study to examine the association between gestational PCBs/PCDFs exposure and auditory function in Yucheng children’s early adulthood. The main findings of current studies were as follows: 1) 30 year follow-up of mortality in the Yucheng cohort as compared to a neighborhood reference group found increased deaths from liver diseases, cardiovascular diseases, systemic lupus erythematosus, and neoplasms including stomach cancer and lymphatic and hematopoietic tissue cancer. 2) A meta-analysis of Yucheng and Yusho cohorts showed similar elevation from all cancer, lung cancer, heart disease, and hepatic disease mortalities in exposed men. Furthermore, a new finding of elevated liver cancer mortality in exposed women was identified. 3) Gestational exposure to PCDFs caused adverse asymmetrical hearing effects detectable even in early adulthood. Our studies suggest that the health care policy for Yucheng victims should include, but not limited to, stomach, liver, lung, and lymphatic and hematopoietic tissue cancer screening as part of the regular health examination. Besides, we suggest that Yucheng children should receive as much health care as first-generation Yucheng victims.
36
Wang-RuJhuang and 莊旺儒. "Removal of Polychlorinated Dibenzo-p-dioxins, Dibenzofurans and Polychlorinated Biphenyls from Municipal Solid Waste Incinerator by Using Air Pollution Control Devices." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/syt7uz.
Full textAbstract:
碩士國立成功大學
環境工程學系
103
Polychlorinated Dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are the main compounds of persistent organic pollutants (POPs). PCDD/Fs and PCBs both have high toxicity, low median lethal dosage (LD50). PCDD/Fs and PCBs in atmosphere were easily transferred into ecosystem by dry and wet deposition, and cause biomagnification and bioconcentration. The main sources of PCDD/Fs and PCBs in environment include waste incineration, power generation, energy industry, mental smelting and some chemical industry. In this study, we focused on the removal efficiencies of PCDD/Fs and PCBs using air pollution control techniques, such as semi-dry sorbent injection, activated carbon injection, and fabric filter in the stack flue gases of municipal solid wastes incinerator (MSWI). In this study, the removal efficiency of particles for semi-dry sorbent injection, activated carbon injection and fabric filter, whole air pollution control devices were 39.8%, 97.35% and 98.25%, respectively. The removal efficiency of total-PCDD/Fs-TEQ for semi-dry sorbent injection, activated carbon injection and fabric filter, whole air pollution control devices were 30.65%, 99.0% and 99.35%, respectively. According to PCDD/Fs congener profiles, OCDD and 1,2,3,4,6,7,8-HpCDD were highly dominant in PCDDs parts, OCDF and 1,2,3,4,6,7,8-HpCDF were mainly in PCDFs parts in stack flue gas. The removal efficiency of total-PCBs-TEQ for semi-dry sorbent injection, activated carbon injection and fabric filter, whole air pollution control devices were 41.55%, 95.9% and 97.85%, respectively. According to PCBs congener profiles, PCB-77 was main species, followed by PCB-118 in stack flue gas. The results of removal efficiency in this study can compared with others incinerators, and develop relevant strategies to reduce the emission of PCDD/Fs and PCBs during incineration process.
37
Wei-YuHuang and 黃偉育. "Characteristics of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans of the Atmosphere in Northern Taiwan." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/38368554721750241821.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
99
The objectives of the present study were to know the characteristics of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Dibenzofurans (PCDFs) in northern Taiwan. These areas were chosen to sample the concentrations of PCDD/Fs in the atmosphere in the vicinity of three municipal solid waste incinerators (MSWIs), a total of 42 air samples were collected and analyzed for 17 PCDD/Fs. The mean PCDD/Fs concentrations at these areas were 0.36, 0.449 and 0.575 pg/Nm3, respectively. The mean TEQ concentrations at these areas were 0.0207, 0.0272 and 0.0297 pg I-TEQ/Nm3, respectively. From the Comparison of PCDD/Fs congener profiles in the vicinity of three MSWIs, Part of OCDD, 1,2,3,4,6,7,8-HpCDD and OCDF were much high proportion. According to the percentage of gas-particle partitioning in the ambient air, the PCDD/Fs concentrations in the atmosphere were mainly in particle phase. For dry depositions, the dominant mechanism of the dry deposition was the particle-phase deposition. The PCDD/F dry deposition fluxes in the vicinity of three MSWIs in the atmosphere were 131,196 and 217 pg/m2-day, respectively.
38
Chiou, Shiau-Ling, and 邱曉玲. "Quality of life affected by previous exposure to polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs)." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/18771027040567151824.
Full textAbstract:
碩士國立臺灣大學
職業醫學與工業衛生研究所
98
Background and Purpose: Polychlorinated biphenyls (PCBs) and Polychlorinated dibenzofurans (PCDFs) are lipophilic pollutants and are known to cause multiple health outcomes in exposed animals and humans. In 1979, approximately 2000 people in central Taiwan were exposed to rice oil contaminated with PCBs and their heat-degradation products, mainly PCDFs, and many manifested by fatigue, skin disorder, abnormal liver function, and other symptoms. No study has documented the health-related quality of life among people exposed to PCBs/PCDFs in the past 30 years. Objectives: This study aimed to determine whether quality of life (QOL) was affected in people exposed to PCBs/PCDFs, as compared to the QOL obtained from background population selected from the National Health Interview Survey (NHIS) in 2001 in Taiwan. Methods: A total of 1,231 exposed subjects with previous PCBs/PCDFs exposure were invited to assess their quality of life by WHO quality of life-BREF (WHOQOL- BREF) Taiwanese version Questionnaire in 2008. Similar survey was done in 2001 in the NHIS study. For those exposed subjects satisfactorily completed the QOL questionnaire, comparisons were obtained from the QOL results randomly sampled from those background individuals matched for age, sex, and county using 1:3 match. Results: A total of 279 exposure subjects (23%) satisfactorily completed the questionnaire. Between the exposed and unexposed referents, the scores of overall QOL were 52.4±8.9, 58.2±6.1. As for individual domains, those of physical health were 14.0±2.3, 15.5±1.9, those of psychological health 12.7±2.8, 14.2±1.9, those of social relationships 13.0±2.5, 14.7±1.9, and those of environment 12.6±2.3, 13.9±1.8. In overall and individual domain scores, exposed people were significantly lower than those of the background population. After adjusted for age, education, gender, occupation, marriage, smoking and drinking, the exposed scored lower than the background in all overall health and individual domains; as well as the following QOL question items: energy, sleep, work capacity, ability to concentrate, bodily appearance, respected/feeling of acceptance, sexual life, and lacking of discomfort/pain. Conclusion: Exposure to PCBs/PCDFs 29 years ago seemed to have adverse effects on overall score of quality of life, as well as on various aspects of quality of life, namely, physical, psychological, social, and environmental domains.
39
Wang, Ya-Hsin, and 王雅馨. "Characterizing the Emissions of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans from Secondary Aluminum Smelters." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/39566959540026535193.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系
92
Two secondary aluminum smelters (secondary ALSs) were sampled and measured for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to investigate the congener profiles of PCDD/Fs in the stack flue gases and emission factors and emission rates from the stack flue gases. Each total five stack flue gases and one bottom ash and fly ash was sampled from these two secondary ALSs (A and B) during March 3~5, 2003 and January 27~29, 2004. Furthermore, five flue gas samples were sampled from the fore of the bag filter. Each sample was last for 2~3 hours. The results are as the follows. The PCDD/F I-TEQ concentration in the stack flue gases of A was 10.6 ng I-TEQ/Nm3. 1,2,3,4,6,7,8-HpCDD and OCDD were the most abound congeners in PCDDs while 2,3,7,8-TeCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,6,7,8-HpCDF and OCDF were the most abound ones in PCDFs. The mean PCDD/F emission factor was 536 μg/ton-feedstock (RSD: 44.5﹪), while the corresponding I-TEQ emission factor was 55.7 μg I-TEQ/ton-feedstock (RSD: 84.7％). The mean PCDD/F emission rate was 812 mg I-TEQ/hr (RSD: 73.6％). The PCDD/F I-TEQ concentration in the stack flue gases of B was 1.45 ng I-TEQ/Nm3. 1,2,3,4,6,7,8-HpCDD and OCDD were the most abound congeners in PCDDs while 2,3,4,7,8-PeCDF, 1,2,3,4,6,7,8-HpCDF, 2,3,7,8-TeCDF and 1,2,3,7,8-PeCDF were the most abound ones in PCDFs. The mean PCDD/F emission factor was 280 μg/ton-feedstock (RSD: 39.8﹪), while the corresponding I-TEQ emission factor was 40.4 μg I-TEQ/ton-feedstock (RSD:45.5％). The PCDD/F I-TEQ concentration in the stack flue gases of A was 7.3 times higher than that of B. It may be result from that the feedstock rate of A was 37.6 times higher than that of B, the intrinsic differences in their involved feeding materials, furnace operating conditions, and air pollution control devices (APCDs). The PCDD/F I-TEQ contents in the bottom ash and fly ash of A were 0.162 and 5.59 ng I-TEQ/g, respectively. 1,2,3,4,6,7,8-HpCDD, OCDD, 1,2,3,4,6,7,8-HpCDF and OCDF were the most abound congeners in bottom ash while 1,2,3,4,6,7,8-HpCDF and OCDF were the most abound ones in fly ash. The PCDD/F I-TEQ contents in the bottom ash and fly ash of B were 0.00761 and 0.172 ng I-TEQ/g, respectively. OCDD、1,2,3,4,6,7,8-HpCDF and OCDF were the most abound congeners in bottom ash while 1,2,3,4,6,7,8-HpCDF and OCDF were the most abound ones in fly ash. By comparing the PCDD/F congener profiles of bottom ash and fly ash, the fraction of PCDFs of fly ash was much higher than that of bottom ash. Furthermore, the PCDD/F contents of fly ash was higher than that of bottom ash. It reveals that de novo mechanism increases the PCDD/F contents of fly ash. The removal efficiencies of PCDD/Fs by bag filters of these two secondary ALSs (A and B) were 5.94﹪and 5.88﹪, respectively. The elimination of PCDD/Fs by bag filter is very limit. The characteristics of PCDD/F emissions from local secondary ALSs, which were established in this study could be an useful information for control PCDD/Fs in the future.
40
Huang, Ping-Wei, and 黃柄瑋. "Modification genes for CYP1A2 inducibility among people exposed to polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs)." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/85233692810025349024.
Full textAbstract:
碩士國立臺灣大學
職業醫學與工業衛生研究所
97
Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-furans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) are all important endocrine disrupting chemicals and also persistent organic pollutants. Among them, 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is known to cause most significant health effects in humans. The PCDFs have similar structure and toxicity as PCDDs. Approximately 2000 people were exposed to rice oil contaminated with polychlorinated biphenyls (PCBs) and their heat-degradation products, mainly polychlorinated dibenzofurans (PCDFs) in central Taiwan in 1979. CYP1A2 activity was found to be induced by such exposure in exposed individuals. The aryl hydrocarbon receptor (AhR) pathway was known to be critical in mediating such enzyme induction. Aryl hydrocarbon receptor nuclear translocator (ARNT) and AhR repressor (AhRR) played important roles in transcriptional regulation of AhR. In order to determine whether the ARNT and AhRR polymorphisms are associated with individual inducibility of CYP1A2. We examined the people exposed to PCBs and PCDFs and their community controls, 173 previously participated in a study on CYP1A2 activity as measured by caffeine metabolic rate, which was in turn found to be positively associated with serum 2,3,7,8-TCDD toxic equivalency (TEQ). Genotyping was done for the following SNPs：AhRR(rs2292596)(C/G), ARNT(rs7517566)(A/G), ARNT(rs3820541)(C/G), ARNT(rs3768016)(C/T), and ARNT(rs2228099)(C/G). The allele frequencies of AhRR (rs2292596) were 0.62 for allele C, 0.38 for allele G; those for ARNT (rs7517566) were 0.79 for allele A, and 0.21 for allele G, ARNT (rs3820541) 0.82 for allele C and 0.18 for allele G, ARNT (rs3768016) 0.58 for allele C and 0.42 for allele T, and ARNT (rs2228099) 0.59 for allele C and 0.42 for allele G. At a similar TEQ dose range, those subjects with AhRR GG genotype had the highest induced CYP1A2 activity, followed by those with CG genotype. Those with CC genotypes had lowest inducibility (p<0.05). ARNT(rs3768016) CC genotype had highest inducibility, followed by CT, and TT genotypes. ARNT (rs2228099) GG genotype had highest inducibility, followed by CG, and CC genotypes. We conclude that AhRR and ARNT genotypes might interact with PCBs and PCDFs in cytochrome P450 enzyme induction effects.
41
Hou, Hsiao-Chung, and 侯孝中. "Both Dry and Wet Depositions of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Atmosphere." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/68550974764122540168.
Full textAbstract:
碩士國立成功大學
環境工程學系碩博士班
96
The objectives of the present study were to know the differences and the annual variances of the dry and wet depositions of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Dibenzofurans (PCDFs) between kinds of areas. A commercial suburban area, an industrial urban area, a coastal rural area and an agricultural rural area were chosen to seasonally sample the concentrations of PCDD/Fs in the atmosphere in each kind of area. Then, the dry and wet monthly deposition fluxes of PCDD/Fs were calculated from the seasonally concentrations of PCDD/Fs in the atmosphere with the dry/wet deposition models. This research indicated that the most PCDD/Fs were adsorbed on the surface of the particulates in the atmosphere. The atmospheric concentractions of PCDD/Fs in the commercial suburban area, the industrial urban area and the coastal rural area which all were located in the north Taiwan were higher in winter and lower in spring, whether those in the agricultural rural area located in the south Taiwan were higher in spring and lower in summer. For dry depositions, the dominant mechanism of the dry deposition was the particle-phase deposition. The dry deposition fluxes of PCDD/Fs in the commercial suburban area, the industrial urban area and the coastal rural area in spring and autumn were higher than those in summer and winter, though othes in the agricultural rural area were higher in spring and winter. The dry deposition fluxes of PCDD/Fs highly negative-correlated with the ambient temperatures. For wet depositions, the dominant mechanism of the wet deposition was the particle scavenging. Due to the rainy season of the plum rains, the typhoons and the eastern-north monsoons, the wet depositions fluxes of PCDD/Fs were two- or three-peaks phase distributions within monthes. The wet deposition fluxes of PCDD/Fs highly positive-correlated with the rainfall and the relative humidity, but negative-correlated with the ambient PM10 concentraction and PM10/PM2.5 ratio. For total depositions, the dry deposition was more important the the wet deposition of PCDD/Fs to total depositions, and the artificial activities influence the fluxes of total depositions of PCDD/Fs. The fluxes of total depositions of PCDD/Fs highly positive-correlated with the rainfall, however, the fluxes of total depositions of PCDD/Fs just lowly or medially correlated with the meteorological conditions.
42
Wang, Lin-Chi, and 王琳麒. "Characteristics of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans from Emission Sources and in the Atmosphere." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/46293610550194164748.
Full textAbstract:
博士國立成功大學
環境工程學系碩博士班
91
This study investigates the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from emission sources and in the atmosphere. By consulting the PCDD/F inventories of other countries, 13 municipal solid waste incinerators (MSWIs), five medical waste incinerators (MWIs), four sinter plants, four electric arc furnaces (EAFs), four secondary aluminum smelters (secondary ALSs) and two crematories were chosen to investigate after considering the social and industrial activities in Taiwan. The emission factors of PCDD/Fs from the stack flue gases of these emission sources were determined and the overall PCDD/F emission quantities to the atmosphere in Taiwan is estimated. In addition, this study attempts to clarify the effects of chlorine content in the waste on the formation mechanisms of PCDD/Fs in full scale incinerators by using the principal component analysis (PCA) to compare the congener profiles of PCDD/Fs in the stack flue gases. Finally, the influence by the emission of MSWIs on the atmosphere are assessed. The conclusions of this study are summarized as follows. 1. The emission factors of PCDD/Fs from the stack flue gases of MSWIs, MWIs, sinter plants with selective catalytic reduction (SCR), sinter plants without SCR, EAFs, secondary ALSs and crematories are 0.0961、20.0、0.970、3.13、1.82、21.5 μg I-TEQ/ton-(waste or feedstock) and 9.86 μg I-TEQ/body, respectively. 2. In Taiwan, the annual emissions of PCDD/Fs from MSWIs, MWIs, sinter plants, EAFs, secondary ALSs and crematories are 0.750、0.369、44.7、19.9、9.52 and 0.838 g I-TEQ/year; the estimated total annual emission of PCDD/Fs from these six important sources is 76.1 g I-TEQ/year. Considering that it represents 60-80% of the total PCDD/F emissions, the total PCDD/F emissions into the atmosphere in Taiwan is estimated as 95.1-127 g I-TEQ/year. These results reveal that the annual emissions of PCDD/Fs from MSWIs are very minor to those of metallurgical processes since strict emission limit have been applied to MSWIs in Taiwan. 3. PCDD/Fs are indeed decomposed (75.5% and 69% on ng and ng TEQ bases, respectively) by SCR and not only reduced in degree of chlorination. 4. The indicatory PCDD/Fs of MSWIs and MWIs are OCDD, 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,7,8,9-HpCDF, 1,2,3,7,8-PeCDF, OCDF, respectively; while those of metallurgical processes are 2,3,7,8-TeCDF, 1,2,3,7,8-PeCDF and 2,3,4,7,8- PeCDF. 5. When the chlorine level in the feeding waste is below the threshold value at 0.8% - 1.1%, the formation of PCDDs dominates. While the chlorine level in the feeding waste exceeds this threshold, the rates of formation of PCDFs increase faster than those of PCDDs, probably because when PCDD/Fs are formed from PAHs, the formation rates of PCDFs are higher than those of PCDDs. 6. The PCDD/Fs concentration in the atmosphere of background area is 0.00634 pg I-TEQ/Nm3. 7. The impact of the crematories to the surrounding environment was greater than that of MSWIs because the crematory had a low stack and installed without appropriate air pollution control devices. 8. The mean PCDD/Fs concentration of air quality monitoring stations was 0.0931 pg I-TEQ/Nm3, which was close to that of maximum ground concentrations of MSWIs and 15 times higher than that of background area. It revealed that PCDD/Fs emission sources existed in southern Taiwan. 9. By using PCA, cluster analysis and indicatory PCDD/Fs, the metallurgical processes were identified as the dominating PCDD/Fs emission sources in southern Taiwan, meanwhile, the influence of mobile sources can not be ignored.
43
Lin, Ching-Hsuan, and 林靜萱. "Levels of polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans in breast milk from Pingtung area." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41232618703351854804.
Full textAbstract:
碩士國立屏東科技大學
環境工程與科學系所
104
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) are a class of persistent organic pollutants (POPs) which widely determined in environment and still raised the globally public concern. Due to their chemical and physical character, high lipophilicity and toxicity, bioaccumulation and biomagnifications caused the potential adverse effect on ecosystem and human. Breast milk is an important sample for understanding the postnatal exposure of POPs in newborn and infant. Therefore, the aim of this study is thus to investigate concentrations of PCDD/Fs and PBDD/Fs in breast milk to further assess the impact on newborn and infant via feeding breast milk. In the present study, participants were healthy pregnant women which randomly recruited from medical center of Pingtung areas in Southern Taiwan between December 2014 and June 2016. All of the participants answered questionnaires and offered their breast milk samples. Twenty five breast milk samples were measured by chemical analysis. Seventeen PCDD/Fs and twelve PBDD/Fs were analyzed with a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Our result showed that mean concentration of PCDD/Fs and PBDD/Fs were 2.89±1.18 and 0.117 pg WHO2005-TEQ/g lipid, respectively. Participants education is master which PCDD/Fs levels were significant lower than those high school (p=0.008) and university (p=0.031). Low concentration of PCDD/Fs was also found in high annual income (over 1 million) participants which were significant lower than low annual income (300-600 thousand). The parameters including, Age, number of birth, BMI and live together with smoker are more important factors than consumer of food. Evaluation the daily intake (DI) of PCDD/Fs, mean concentration of DI in Taiwanese infant is 12.1 pg TEQ/kg bw/day, our result showed the similar order magnitudes of DI to those found in other countries.
44
Wang, I.-Ching, and 王怡靜. "Assessment of Bioaccumulation in Fish and Human Intake of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/69480401869336494464.
Full textAbstract:
博士國立成功大學
環境工程學系碩博士班
98
Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs) are proven as carcinogenic and mutagenic compounds, and are recognized as poisons of the century. In this study, accumulation of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) between environmental media and fish were investigated. In addition, the dietary intake of PCDD/Fs for Taiwanese was discussed. The first part of the study includes the PCDD/F and DL-PCB levels in environmental media (water, sediment, and feed) and in farmed fish of different age. To observe the accumulation of PCDD/Fs and DL-PCBs in farmed fish, tissue samples of hatchling, 2-month, 15-month, 24-month, and 36-month-old were collected, and the samples of all the environmental media were taken right after each time fish samples were collected. PCDD/F levels in a total of 25 food items in Taiwan and the PCDD/F intake of Taiwanese were surveyed in the second part of this study. PCDD/F intake of some special population such as duck farmer who may ingest high quantity of contaminated duck eggs were also determined. The results of the first part showed that PCDD/F and DL-PCB levels in water and sediment from fish farm were lower than those from natural environment such as rivers and lakes. The discharge of farm water and rearrangement of farm land each time fish were harvested may result in low levels of PCDD/Fs and DL-PCBs in water and sediment samples. In Environmental medium, PCDD/F levels were all higher than DL-PCB levels. However, DL-PCBs were found to contribute more to the TEQ than PCDD/Fs were in all the fish samples. Both PCDD/Fs and DL-PCBs concentrations rose with the period that groupers were raised. The results in this study conclude that PCDD/Fs and DL-PCBs could accumulate in fish tissues, and diet is the main source of the accumulations. In the second part of this study, it was observed that shellfish and saltwater fish possessed the highest PCDD/Fs levels, 9.82 and 3.60 pg WHO-TEQ/g, respectively, on the lipid basis. The dietary intakes of humans at ages of 12-18, 19-64, and over 65 were determined. The estimated intake were between 21.8 (female teenagers) and 37.6 pg (male seniors) WHO-TEQ/day; the levels varied with the dietary habits. The PCDD/F intakes for all human groups are far below the tolerable limit of 70 pg WHO-TEQ/Kg b.w./month. In addition, the daily PCDD/F intake levels for duck farmers consuming average and large amounts of PCDD/F contaminated duck eggs were examined. The result shows that consuming more than one duck egg with level higher than 10 pg WHO-TEQ/g lipid of PCDD/Fs per day could lead to a PCDD/F intake level higher than the tolerable limit. However, for normal population, there is little risk to ingest intolerable amount of PCDD/Fs because of intake of contaminated duck eggs.
45
JustusMutuku and 張克平. "Atmospheric PM2.5 and Depositions of polychlorinated dibenzo-P-dioxins and dibenzofurans in Taitung County, Taiwan." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/mbtexh.
Full textAbstract:
碩士國立成功大學
環境工程學系
105
Taitung lies on the South East side of Taiwan; geographically, it mostly consists of mountains and a coastal stretch. It has a tropical monsoon climate, the wet season runs from May to October, while the dry season runs from November to April. The region has a high humidity and its annual average temperature ranges from 22 to 25 0C. The tropical climate in Taitung region is different in the sense that it is more foggy than sunny. The main economic activities in Taitung are farming and tourism. Because of its sparse population, lack of urbanization and industrialization, Taitung County has managed to remain a pollution free zone compared to other regions of Taiwan. As a result, it has been left out on most of the studies on air pollution in Taiwan. This study focused on the roles of meteorological factors to the ambient air concentrations and depositions of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) and particulate matters (PM2.5) in Taitung County, Taiwan. Wet and dry depositions of dioxins in the region were also quantified. The average annual PM2.5 concentrations ranged between 9.6 to 11.0 μg m-3. Taiwan applies the 2012 PM2.5 world air quality index as its standard for the EPA which is currently at 15 µg m–3. According to these standards, Taitung County did not exceed the set limits for the concentration of PM2.5 in ambient air for the entire study period. However, Guanshan station (11 µg m–3) had a higher concentration of PM2.5 compared to Taitung station (9.6 µg m–3). To quantify the concentration of dioxins in the atmosphere in Taitung County, Taiwan, a regression line relating the mass concentration of PCDDs/Fs to PM10 was plotted. Compared to other studies, the concentration of dioxins in Taitung County was lower than the other regions in Taiwan. The simulated concentration of dioxins in the atmosphere ranged between 0.0106 to 0.0117 pg WHO 2005-TEQ m–3. There was an upward trend in the concentration of the dioxins for the two years in the entire area of study concentrations in 2014 was 0.0106 while the concentration in 2015 was 0.0115 pg WHO 2005-TEQ m–3 . Temperature and atmospheric pressure were used to model the partitioning of dioxins into their gaseous and particulate phases for the four seasons of the year. Higher chlorinated dioxins (hexa-, hepta- and octa-chlorinated) were the dominant congeners in the particulate phase while the low chlorinated congeners (tetra- and penta-chlorinated dioxins) existed almost wholly in their gaseous phase. Total deposition in the Taitung County ranged between 58.2 and 189.5 pg WHO2005-TEQ m-2 month-1. Dry deposition was dominant in region compared to wet deposition and it ranged between 35.7 to 188.5 pg WHO2005-TEQ m-2 month-1 with the dry deposition velocities ranging between 0.17 and 0.52 cms-1. The average dry deposition velocity was 0.39 cms-1. Wet deposition was dependent on the number of days experiencing precipitation and it ranged between 0.39 to 30.3 pg WHO2005-TEQ m-2 month-1. The range of the scavenging ratios was between 1351 and 41197 for the entire study period.
46
Hu, Shu-Chuan, and 胡淑娟. "A Survey Study on the Concentrations of Polychlorinated Dibenzo-p-dioxins, Dibenzofurans, and Dioxin-like polychlorinated Biphenyls in the Baby Formulas in Taiwan." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/8mqvqv.
Full textAbstract:
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 important persistent organic pollutants. They were reported to cause reproductive and developmental effects in human and the infant is more vulnerable than the adult. Over 90% of human exposure to PCDD/PCDF/PCBs is due to food consumption. In Taiwan, less than 30% of mothers breast-feed their babies. For those infants without breast-feeding, the baby formula is their major exposure source. The objectives of this study are to measure the concentrations of 7 PCDD, 10 PCDF, and 12 dioxin-like PCB congeners in the major baby formulas consumed in Taiwan and to assess the first 6-month exposure of PCDD/PCDF/PCBs from baby formulas consumption for infants. The list of top-ten baby formula products was obtained by questionnaires answered by nursing mothers. The 17 PCDD/PCDF and 12 dioxin-like PCB congeners are analyzed according to the US EPA Method 1613B and 1668A, respectively, using high-resolution gas chromatography with high-resolution mass spectrometry. The mean toxic equivalent concentrations of PCDD/PCDFs and dioxin-like PCBs for these baby formula products were 0.73(±0.18) and 0.33(±0.05) pg WHO98-TEQ/g-lipid, respectively. The first 6-month exposure to PCDD/PCDFs and dioxin-like PCBs for infants via formula consumption are 19 and 9 pg WHO98-TEQ/day, respectively. These are equal to 2.5 and 1.5 pg WHO98-TEQ/kg/day, respectively. The accumulated intake of PCDD/PCDFs and dioxin-like PCBs in the 6-month period are 3.3 and 1.6 ng WHO98-TEQ, respectively.
47
Ming-WeiChen and 陳明尉. "Distribution Characteristics of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in the water and Waste Incineration Systems." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/n8z5pw.
Full textAbstract:
博士國立成功大學
環境工程學系碩博士班
101
In this study, two major aims are to prevent the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) transfer to surrounding environment in a heavily dioxin contaminated site and to reduce the PCDD/F emission from a medical waste incinerator (MWI). First, the contents of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in soil and water impacted by a chemical factory (chloralkali and pentachlorophenol) and both the PCDD/F contents in soil (14.4 µg I-TEQ kg-1) and water (11.97 pg I-TEQ L-1) were heavily contaminated. Additionally, the PCDD/F distributions in the aquatic environment (suspended solid and dissolved phases) were investigated by performing a water tank experiment with 30 g of soil and 20 L of water. Moreover, the effects of PCDD/F distributions in water were estimated base on three soil sizes (26, 180 and 250 μm). From a mass balance perspective, the suspended solid, dissolved phase and settled soil contributed 0.07%, 0.005%, and 99.93%, respectively, with the highest amount of PCDD/F in the settled soil deserve more attention. The PCDD/F distribution in the suspended solid phase was dominant, while its distribution was independent of soil size. Additionally, placing soil with a high PCDD/F content in water increased the PCDD/F content in suspended solid phase. Moreover, the equation developed in this study can accurately predict the PCDD/F partition between the suspended solid and dissolved phases. Second, this study investigated the polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) removal efficiencies in two medical waste incinerators (MWIs) -MWI-A and MWI-B, with waste burning capacities of 9.12 and 12 tons per day, with dual-and single-bag filter systems, respectively. The PCDD/Fs in the stack flue gas and fly ashes of each air pollution control device (APCD) unit were collected concurrently. Based on mass balance, it was determined that the major PCDD/F removal occurred in the bag filter system with activated carbon injection (ACI). The total PCDD/F emission removal efficiencies for the whole dual-bag filter system, bag filter 1 (BF1), bag filter 2 (BF2) in MWI-A and the single bag filter system (BF) in MWI-B were 99.7%, 84.8%, 98.0%, 99.0% on the mass basis, respectively. The PCDD/F emission ratio (the escaped PCDD/F ratio after all APCDs) with the dual-bag filter system was over four times lower than that with a single bag filter. The results demonstrate a very efficient way to reduce the excess PCDD/F emissions incurred by intermittent operations and irregular waste feeding.
48
Chun-WeiTu and 杜俊緯. "Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins/ Dibenzofurans in the Ambient Air at the Mountain Yangming." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/kxufc3.
Full textAbstract:
碩士國立成功大學
環境工程學系
104
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are carcinogenic persistent organic pollutants (POPs) that can bioaccumulate in the ecosystem, cause endocrines disruption and undergo long range transport in the atmosphere. Atmospheric deposition including those of dry and wet is a primary pathway for the transfer of POPs to terrestrial and aquatic ecosystems. In this study, the characteristics of PCDD/Fs in the ambient air at Mt. Yangming were simulated by the PM10 versus PCDD/Fs concentration regression analysis, gas-particle partition modeling, dry deposition, and wet deposition simulations. Dry and wet deposition fluxes were obtained from the combination of the PCDD/F concentrations, meteorological information, dry deposition velocities, and scavenging ratios. The dry deposition fluxes of PCDD/F-WHO2005-TEQ increase with decreasing temperature, while increase with higher degree of chlorine numbers on PCDD/F homologues. However, a wet deposition flux increase with stronger rainfall intensity. The congener profile of PCDD/F-WHO2005-TEQ indicates that total deposition fluxes, 2,3,4,6,7,8-HxCDF, 2,3,4,7,8-PeCDF dominate the deposition fluxes. The simulated PCDD/F concentration during 2014, at Yangming, ranged between 0.00725 and 0.0176 pg WHO2005-TEQ /Nm3, while those during 2015 ranged between 0.00761 and 0.0162 pg WHO2005-TEQ /Nm3. WHO2005-TEQ ratios of PCDDs to PCDFs at both year are all less than 1 (averaged 0.407), indicating that PCDF dominate the total toxicity. During 2014, at Yangming, the monthly dry deposition flux of total PCDD/Fs-WHO2005-TEQ ranged between 9.63 and 91.7 pg WHO2005-TEQ /m2 ∙month, while those during 2015 ranged between 12.2 and 61.0 pg WHO2005-TEQ /m2 ∙month. At the other hand, during 2014, at Yangming, the monthly wet deposition flux of total PCDD/Fs-WHO2005-TEQ ranged between 6.29 and 138.3 pg WHO2005-TEQ /m2 ∙month, while those during 2015 ranged between 4.95 and 79.3 pg WHO2005-TEQ /m2 ∙month. The annual total wet deposition flux of total PCDD/Fs- WHO2005-TEQ concentration at Yangming were 637.3 and 511.1 pg WHO2005-TEQ /m2 ∙year in 2014 and 2015, respectively. During 2014, at Yangming, the monthly total deposition flux of total (dry + wet) PCDD/Fs-WHO2005-TEQ ranged between 34.4 and 178.0 pg WHO2005-TEQ /m2 ∙month, while those during 2015 ranged between 28.1 and 119.1 pg WHO2005-TEQ /m2 ∙month. The annual total deposition flux of total PCDD/Fs-WHO2005-TEQ at Yangming were 969.7 and 803.6 pg WHO2005-TEQ /m2 ∙year in 2014 and 2015, respectively. At Yangming, during 2014, the fraction contribute by dry deposition ranged between 10.9% and 81.7%, while during 2015 ranged between 16.4% and 82.4%. Mean fraction contribute by dry deposition at Yangming were 35.7% and 39.2% in 2014 and 2015, respectively. The lowest fraction of individual PCDD/Fs dry deposition in total (dry + wet) deposition fluxes was found in fall in both years. It may be due to high rainfall intensity occurred in fall and also the day with precipitation were more in fall. The simulated results of this study combine with the previous measured data provided useful information for the future policy making and further studies. In Taiwan, more measured data associated with dry deposition velocity and wet scavenging is needed for a more precise and complete investigation in the future.
49
Kuan-LinLee and 李冠霖. "Atmospheric PM2.5 and Depositions of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Kaohsiung Areas, Taiwan." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8ytxgt.
Full text
50
Lin, Long-Full, and 林龍富. "Characteristics of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans from Emission Sources and in the Environmental Media." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/10713990978643451689.
Full textAbstract:
博士國立成功大學
環境工程學系碩博士班
95
The objectives of the present study were to develop (1) emission factors of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) for various industrial sources which seldom being investigated; (2) the overall PCDD/F emission inventory in Taiwan as well as in the KC area; (3) correlation between banyan leaf compositions and ambient air concentration of PCDD/Fs; (4) dry and wet deposition fluxes of PCDD/Fs in the ambient air of two municipal solid waste incinerators (MSWIs); and (5) to clarify the influence of deposition on the soil content of PCDD/Fs. To achieve these goals, a total of 51 flue gas samples from seventeen industrial sources were collected to develop emission factors. In addition, a total of 95 flue gas samples from 20 sources including coal-fired power plants, open burning of rice straw, wax apples, and ritual paper, and diesel engines et al., were collected and analyzed for 17 PCDD/Fs to develop emission inventory. Furthermore, a total of 56 samples for each environment media including air, vegetation, and soil, were collected from the environment media of two MSWIs to establish atmospheric level and to estimate deposition fluxes. The results of this study show that mean PCDD/F concentration of the secondary zinc smelter (Zn-S) and secondary copper smelter (Cu-S) is 2.44 ng I-TEQ Nm-3 (at 11% O2), which was found to be greater than that of industrial waste incinerators (mean concentration = 0.15 ng I-TEQ Nm-3). These results imply that the controlling of secondary metallic melting processes is more important for the reduction of PCDD/F emissions than industrial waste incineration. In addition, the emission factor of PCDD/Fs from coal-fired power plants (620 ng I-TEQ ton-1) obtained in this study is greatly higher than the value of previous study (2.34 ng I-TEQ ton-1). It means that in Taiwan the air pollution control devices for PCDD/F removal in certain power plants need to be more efficient. The emission data showed that there is a total annual release to air of 6.1 and 95 g I-TEQ from major sources in the KC area and Taiwan, respectively. The dominant sources of PCDD/Fs in the KC area are the coal-fired power plants, secondary aluminum smelting, electric arc furnaces, and open burning of rice straw, which contributed about 56, 17, 13, and 3.3% to the total, respectively. However, in Taiwan, the dominant sources of PCDD/Fs are the iron ore sintering, coal-fired power plants, electric arc furnaces, and open burning of rice straw, which contributed about 32, 28, 23, and 8.1% to the total, respectively. Furthermore, there is a good correlation between banyan leaf compositions and ambient air concentration of PCDD/Fs using an average data of individual measurement for each sampling location. This implies that an ambient data for long period monitoring (longer than three months) can be used to predict the composition in vegetation. In the vicinity of MSWI-GS and MSWI-RW, the annual deposition fluxes of PCDD/Fs are about 8.59 and 10.1 ng I-TEQ m-2 year-1, respectively, and wet deposition contributed 42% and 34% to the total, respectively, it reveals that dry deposition is more important than wet deposition. Finally, the dominant congeners of PCDD/Fs in ambient air of MSWIs removed by dry and wet deposition are very similar to that of soil in the vicinity of MSWIs, but some congeners removed by deposition disappeared in the soil, especially the congeners with lower chlorine number. This can be explained as vaporization, biodegradation or photodecomposition. The results of this study showed that coal-fired power plants are very significant sources of PCDD/Fs, the results also provide important database to assist the decision makers for formulating policies to alleviate dioxin concerns.