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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

A Study on the Measurement and Analysis of Mercury in Flue Gas Emitted from Municipal Waste Incinerator and the Adsorption of Gaseous Mercury Chloride by Powder Activated Carbon Derived from the Pyrolysis of Waste Tires

Wu, Chun-Hsin 01 August 2000 (has links)
The objective of this study was to remove mercury vapor from municipal waste incinerator (MWI) by the adsorption of powder activated carbon (PAC) prepared from the pyrolysis of waste tire. The study focused on the measurement of mercury concentration in flue gas emitted from municipal waste incinerator, the preparation of PAC from the pyrolysis of the waste tire and impregnated with sulfur, and the adsorption capacity of mercury by the self-made PAC. The measurement of heavy metals in flue gas emitted from four typical MWIs was conducted in this study. Experimental results obtained from the measurement of mercury from flue gas indicated that the removal efficiency of mercury ranged from 83.71%~96.22%for the tested MWIs. This study revealed that the injection of PAC in flue gas would enhance the removal efficiency of mercury. Besides, oxided mercury (Hg2+) can be removed much more easily than elemental mercury (Hg0). Experimental results obtained from the pyrolysis of waste tires indicated that the pyrolysis temperature of waste tire was approximately 400~500¢J, and the percentage of carbon residue is 35~37%. With higher temperature and water feed rate and longer activation time, the specific surface area and total pore volume of PAC increased while the average pore radius decreased. The highest specific surface area of PAC obtained in this study was 996 m2/g. In addition, experimental results obtained from sulfur impregnation process indicated that the specific surface area of PAC decreased dramatically as sulfur was added to PAC. Experiment results obtained from the adsorption capacity of HgCl2 on PAC by column test indicated that PAC with higher specific surface area could adsorb more HgCl2 at room temperature (25¢J). The adsorption capacity of sulfur impregnated PAC decreased at 25¢J was due to the decrease of specific surface area of PAC. However, results from the comparison of two PAC with similar specific surface area indicated that the PAC with higher sulfur content had higher adsorption capacity. It suggested that the addition of sulfur to PAC could enhance the adsorption of HgCl2 at 25¢J. Experimental results obtained from column tests at 150¢J showed that the adsorption capacity of PAC increased as sulfur content of PAC increased. These results suggested that the adsorption mechanism of HgCl2 by PAC was mainly physical adsorption at lower temperature and it was chemisorption at higher temperature. Besides, the self-made PAC demonstrated the similar adsorption capacity of HgCl2 with commercial PAC used in MWIs.
12

Characteristics of PCDD/ Fs and metal contents in ash from different units in a municipal solid waste incinerator

Lin, Yu-Sheng 13 May 2008 (has links)
This study determined the polychlorinated dibenzo-p-dioxins/ dibenzo- furans (PCDD/Fs) and 22 metals contents in ash in the super heater (SH), economizer (EC), semi-dryer absorber (SDA), fabric filter (FF), fly ash pit (FAP) and bottom residue (BR) in a municipal solid waste incinerator (KTMSWI). Experimental results showed that average PCDD/FS contents in ash samples from the SH, EC, SDA, FF, FAP and BR were 0.102, 0.788, 0.210, 1.95, 2.04 and 0.0218 ng I-TEQ /g, respectively. PCDD/Fs content was very low in the SH and BR due to high temperatures (around 461¢XC in the SH and 914¢XC in combustion chamber). Conversely, total PCDD/Fs content was significantly high in ash samples from the EC (around 340¢XC), mainly because the temperature is within the favorable range of 250-400¢XC for PCDD/FS formation due to de nova reformation mechanisms. Although the SDA operated at 245¢XC, the PCDD/FS content decreased very significantly, mainly because the temperature was relatively low and because calcium carbonate was introduced into flue gases to dechlorinate and dilute chlorine-containing species. PCDD/Fs were captured by the active carbon in the FF. Furthermore, the duration that fly ash remained in the FF was longer than that for other incinerator units, and thus causing an increasing trend of PCDD/Fs level downstream (except the SDA). Total PCDD/Fs emission factors (£gg /ton-waste; £gg I-TEQ /ton-waste) in ash samples from different units were: SH (42.3; 0.846), EC (326; 6.12 ), SDA (58.1; 1.10), FF (1540; 61.3), FAP (2950; 107) and BR (537; 4.31). Most PCDD/Fs in ash were contributed by the FF (about 56%), and the generation of PCDD/Fs in ash was significant (about 35%) during the transfer process from different units to the FAP. A strong and positive correlation in a logarithmic form existed between PCDD/Fs and chlorine (Cl-) contents in ash. The results showed that principal metals in the incinerator ash were Al, Fe, Zn, Ba, Pb and Cu. On average, these six metals accounted for 96.6%, 96.8%, 97.0%, 94.2% and 96.7% of the total metals in SH, EC, SDA, FF and BR ash, respectively. The emission factors of individual metals from different units were obtained. Volatile metals, such as Cd, Sn, Sb, Hg and Pb, were mostly in fly ash, while lithophilic metals, such as Al, Fe, Ti, V, Cu, Mn, Fe, Co, Ni, Cu, Sr, Mo, Ag, Ba and Cr+6 were mainly in bottom ash. Distribution ratios for total metals in SH, EC, SDA, FF and BR ash were 4.87%, 4.26%, 2.89%, 8.17% and 79.81%, respectively. That is, about 20.2% of total metals were in fly ash and most metals (about 79.8%) were in bottom ash. The Pb content in EC ash and Hg content in FF ash were between alarm contents and maximum legal limits, while Cd and Pb contents in FF ash exceeded the maximum legal limits. The existing transportation system for transferring fly ash from different units to a fly ash pit should be modified for recycling the valuable metals. Ash with less than the alarm content for metals content, such as ash from the SH, SDA and BR, can be reused. Ash with metals exceeding the alarm contents, such as ash from the EC and FF, should be collected and transferred to a different fly ash pit for further treatment, such as metal recycling.
13

Persistent organic pollutants (POPs) in soil associated with an active incinerator in Potchefstroom, South Africa / L.P. Quinn

Quinn, Laura Penelope January 2005 (has links)
POPs are a group of chemicals that have been extensively studied over the last few years. The main reason that these chemicals have received so much scientific attention is the myriad of negative effects they have on the environment and human health. The properties that cause the deleterious effects include a high molecular stability, rendering them highly persistent. Added to this is the lipophilic and hydrophobic nature of the compounds. POPs will thus tend to bio-accumulate and bio-magnify in the environment, causing a direct threat to humans and wildlife. To address this threat, the Stockholm Convention on Persistent Organic Pollutants, under the supervision of United Nations Environment programme (UNEP), was initiated and became legally binding on 17 May 2004. All countries, including South Africa, which ratified this agreement, will be expected to monitor and regulate the formation of POPs. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) are all members of the dioxin-like family of POPs. This family of chemicals pose serious health threats such as carcinogenic effects and negative effects on reproduction. These substances, with the exception of PCBs, are formed unintentionally as by-products of industrial and thermal processes. One of the main sources of dioxin-like chemicals is medical waste incinerators. In this project the area surrounding a medical waste incinerator was monitored using a bio-assay technique. The determination of dioxin concentrations is usually preformed by chemical analysis, however, bio-assays have proven themselves to be a cheaper and time-saving screening method. The Toxic Equivalency Quotient (TEQs) determined through bio-assays can support chemical analysis in determining biologically-relevant risk assessments since bio-assay data has ecotoxicological relevance. These assays represent an integrated biological response to chemical pollutants, where biological effects are accounted for which is not possible in chemical analyses. One of the bio-assays used in the determination of the dioxin-like chemical TEQ is the H411 E reporter gene bio-assay. This assay is based on the Ah-receptor mediated toxicity of dioxin-like chemicals. Using this technique the TEQs for areas surrounding an active incinerator were determined, to indicate the distribution of these substances. The TEQs for the soil samples collected ranged between nondetectable and 154 ngTEQ/kg. There was no clear distributional pattern and the total organic carbon content in the soil did not seem to play a crucial role in the distribution of dioxin-like chemicals. Although a decrease in soil tillage showed a corresponding increase in TEQ. The predominant wind direction was taken into account but no correlation could be seen. However, meteorological parameters such as the ambient temperature and low precipitation in the area may have contributed to lower TEQ values. Cytotoxicity excluded data points and the phenomenon has to be addressed. High TEQ values in a residential area where free-range chickens are raised pose a serious concern to the level of dietary dioxin-like chemical intake. Eggs in the area could theoretically contain between 2.75 and 28.75 pgTEQ/g egg fat. Further studies are needed to determine how much dioxin-like chemicals are being transferred to humans through the consumption of free-range eggs / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
14

Persistent organic pollutants (POPs) in soil associated with an active incinerator in Potchefstroom, South Africa / L.P. Quinn

Quinn, Laura Penelope January 2005 (has links)
POPs are a group of chemicals that have been extensively studied over the last few years. The main reason that these chemicals have received so much scientific attention is the myriad of negative effects they have on the environment and human health. The properties that cause the deleterious effects include a high molecular stability, rendering them highly persistent. Added to this is the lipophilic and hydrophobic nature of the compounds. POPs will thus tend to bio-accumulate and bio-magnify in the environment, causing a direct threat to humans and wildlife. To address this threat, the Stockholm Convention on Persistent Organic Pollutants, under the supervision of United Nations Environment programme (UNEP), was initiated and became legally binding on 17 May 2004. All countries, including South Africa, which ratified this agreement, will be expected to monitor and regulate the formation of POPs. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) are all members of the dioxin-like family of POPs. This family of chemicals pose serious health threats such as carcinogenic effects and negative effects on reproduction. These substances, with the exception of PCBs, are formed unintentionally as by-products of industrial and thermal processes. One of the main sources of dioxin-like chemicals is medical waste incinerators. In this project the area surrounding a medical waste incinerator was monitored using a bio-assay technique. The determination of dioxin concentrations is usually preformed by chemical analysis, however, bio-assays have proven themselves to be a cheaper and time-saving screening method. The Toxic Equivalency Quotient (TEQs) determined through bio-assays can support chemical analysis in determining biologically-relevant risk assessments since bio-assay data has ecotoxicological relevance. These assays represent an integrated biological response to chemical pollutants, where biological effects are accounted for which is not possible in chemical analyses. One of the bio-assays used in the determination of the dioxin-like chemical TEQ is the H411 E reporter gene bio-assay. This assay is based on the Ah-receptor mediated toxicity of dioxin-like chemicals. Using this technique the TEQs for areas surrounding an active incinerator were determined, to indicate the distribution of these substances. The TEQs for the soil samples collected ranged between nondetectable and 154 ngTEQ/kg. There was no clear distributional pattern and the total organic carbon content in the soil did not seem to play a crucial role in the distribution of dioxin-like chemicals. Although a decrease in soil tillage showed a corresponding increase in TEQ. The predominant wind direction was taken into account but no correlation could be seen. However, meteorological parameters such as the ambient temperature and low precipitation in the area may have contributed to lower TEQ values. Cytotoxicity excluded data points and the phenomenon has to be addressed. High TEQ values in a residential area where free-range chickens are raised pose a serious concern to the level of dietary dioxin-like chemical intake. Eggs in the area could theoretically contain between 2.75 and 28.75 pgTEQ/g egg fat. Further studies are needed to determine how much dioxin-like chemicals are being transferred to humans through the consumption of free-range eggs / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.
15

Production of glass-ceramics from municipal solid waste (MSW) fly ash

Ghouleh, Zaid. January 1900 (has links)
Thesis (M.Eng.). / Written for the Dept. of Mining, Metals and Materials Engineering. Title from title page of PDF (viewed 2009/06/15). Includes bibliographical references.
16

Estimativa do potencial energético dos resíduos sólidos urbanos por diferentes rotas de tratamento

Silva, Elissandro Rocha da January 2015 (has links)
Orientador: Profª. Dra. Juliana Tófano de Campos Leite Toneli / Tese ( doutorado)- Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2015. / No âmbito da Política Nacional de Resíduos Sólidos, instituída no Brasil no ano de 2010, devem ser considerados como objetivos para a gestão e gerenciamento de resíduos sólidos urbanos (RSU), na seguinte sequência: não geração, redução, reutilização, reciclagem, tratamento e disposição final ambientalmente adequada dos rejeitos. Nesse contexto, este trabalho teve como objetivo principal fornecer subsídios para os gestores analisarem rotas alternativas para disposição final dos resíduos sólidos de grandes centros urbanos levando em consideração o potencial de recuperação energética. Como objeto de estudo, foram considerados os resíduos depositados no aterro sanitário de Caieiras/SP. Foram analisadas três diferentes formas de disposição de RSU que permitem, além do tratamento, a recuperação da energia química da biomassa presente na sua composição e conversão em eletricidade. Os tratamentos considerados foram: ¿ disposição em aterros sanitários com recuperação do biogás, biodigestão anaeróbia em biodigestores e incineração com recuperação energética ¿ avaliando-se principalmente os aspectos tecnológicos, energéticos e ambientais. Para a análise do potencial dos RSU dispostos em aterros sanitários, foram utilizados modelos matemáticos que permitem estimar a produção de biogás em função do potencial de dois importantes parâmetros (potencial de produção de biogás e constante de decaimento). Os resultados obtidos para o aterro de Caieiras apresentaram uma variação de até 54% entre um modelo e o outro, sendo que os valores mínimo e máximo obtidos para a geração de metano no ano de 2015 foram de 100 a 220 milhões de Nm3. Para avaliação da biodigestão anaeróbia em biodigestores, foram avaliados dois modelos matemáticos que permitem estimar a produção de metano em função dos diversos fatores que interferem no processo (concentração de acetato e de micro-organismos, da variação do pH, dentre outros). Os resultados obtidos para a biodigestão anaeróbia apresentaram uma variação de até 32% em relação à faixa considerada para a concentração de sólidos totais (2,4 a 39%), sendo que os valores mínimo e máximo obtidos para a biodigestão anaeróbia da fração orgânica dos RSU foram de 100 e 220 milhões de Nm3 de CH4/ano, respectivamente. No caso da incineração, foram considerados seis modelos matemáticos empíricos (baseados nas análises imediata, gravimétrica e elementar) para estimar o poder calorífico inferior (PCI) dos RSU. Foram consideradas três alternativas: incineração dos RSU sem segregação dos seus componentes, incineração considerando segregação dos materiais recicláveis e incineração considerando a separação da fração orgânica dos RSU para biodigestão. Os resultados obtidos para a incineração apresentaram uma variação de até 40% entre um modelo e o outro, sendo que os valores mínimo e máximo obtidos para o PCI dos RSU foram de 4,87 e 8,26 MJ/kg, considerando a coleta indiferenciada. Baseados nos resultados obtidos, conclui-se que a incineração apresenta os melhores resultados do ponto de vista do potencial de conversão energética. Assim, este trabalho fornece subsídios para os gestores definirem rotas alternativas para disposição final dos resíduos sólidos urbanos, considerando a possibilidade de aproveitamento energético. / Within the framework of National Solid Waste Policy, established in Brazil in 2010, should be considered as principles for the management of municipal solid waste (MSW), in the following order: non-generation, reduction, reuse, recycling, treatment and environmentally sound disposal of waste. In this context, this work aimed to provide subsidies for managers define alternative routes for disposal of municipal solid waste, considering the possibility of energy recovery of waste generated in large urban centers, taking as a basis MSW intended for landfill Caieiras/SP. Three different forms of MSW disposal have been considered that enable, in addition to treatment, the recovery of chemical energy of the biomass present in the composition and conversion of electricity. These treatment forms were - disposal in landfills, anaerobic digestion in biodigesters and incineration - especially considering the technological, energy and environmental aspects. To analyze the potential of MSW disposed in landfills, it was used mathematical models, which allow to estimate the biogas production from the potential of two important parameters (biogas potential and decay constant). The results obtained for Caieiras landfill showed a variation of up to 54% between one model and another being that the minimum and maximum values obtained for methane generation in the year 2015 were 100 to 220 million Nm3. For evaluation of anaerobic digestion in biodigesters, two mathematical models were studied, which allow estimating the methane production from various factors that affect the process (concentration of acetate and mico-organisms, changes in pH, among others). The results for the anaerobic digestion showed a variation of up to 32% for the range of total solids content assumed (2.4 to 39%), and the minimum and maximum values obtained for the anaerobic digestion of the organic fraction of MSW were 100 to 220 million Nm3 CH4/year respectively. In the case of incineration were evaluated six empirical mathematical models (based on immediate analysis, gravimetric and elemental) used to estimate the lower heating value (LHV) of MSW. Three alternatives were considered: MSW incineration without segregation of its components, incineration considering segregation of recyclable materials and incineration considering the separation of the organic fraction of MSW. The results obtained for the incineration showed a variation of up to 40% between one model and another being the minimum and maximum values for the LHV of MSW 4.87 and 8.26 MJ/kg respectively for undifferentiated collection. Based on these results, it is concluded that the incineration provides the best results from the point of view of energy conversion potential. Thus, this work provides subsidies for managers define alternative routes for disposal of municipal solid waste, considering energy use.
17

Planning and Valuation of Investment Project - MSW Incinerator in Banska Bystrica / Planning and Valuation of Investment Project - MSW Incinerator in Banska Bystrica

Lúčanský, Igor January 2014 (has links)
The Master Thesis outlines planning and valuation of solid waste incinerator with energy recovery. The focus of due diligence, made before valuation, is on the assessment of the input data in regard to current and future market situation. The beginning of the thesis explains the valuation process with methods used later on. The two subsequent parts describe respectively current market situation and define data for valuation process made in Excel sheet attached. Before concluding the outcomes are compared with other possibilities with changes in financing structure.
18

Parní turbína pro spalovnu odpadu / Steam Turbine for Waste to Energy

Hodonský, Lukáš January 2018 (has links)
The thesis deals with the design of the steam turbine for a waste incinerator. First, the concept and design of the machine is discussed. Following part is the steam turbine thermodynamics calculation, which is the main part of the thesis. My work also contains calculation of axial force and a simplified calculation of the gearbox. The design sections of individual modules and drawing of a disposition of a steam turbine are made on the based of the calculation.
19

Analýza předčištění pracovní látky pro účely výměny tepla / Analysis of proces fluid pretreatment for heat exchange purpose

Navrátil, Ondřej January 2012 (has links)
This thesis is devoted purification of a gas stream with solid and liquid particles. The problem described in the thesis is connected with a real industrial case – problem of operated waste gas incineration plant. Waste gas going to thermal incineration to flame of natural gas combustion contains solid and liquid particles. Presence of particles causes fouling of waste gas preheater. The main objective of thesis is analysis of situation and operating and space limitations and design of a suitable type of particle collector to reliable elimination of particles from waste gas before entering the gas preheater and thus to mitigation of fouling of preheater heat transfer area.
20

Study on behavior of heavy metals in semi-aerobic landfill sites of municipal solid waste incinerator residues / 都市ごみ焼却残渣の準好気性埋立地における重金属類の挙動に関する研究

Xiong, Yiqun 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22427号 / 工博第4688号 / 新制||工||1732(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高岡 昌輝, 教授 酒井 伸一, 准教授 大下 和徹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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