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.

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.

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.

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.

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.

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.

Les recherches s’inscrivent dans une prospection qui étudie la viabilité de la valorisation du CO2 d’un incinérateur de déchets industriels. Plusieurs licences commerciales existent pour le captage du CO2 dans des gaz de combustion mais il n’existe pas de référence pour le traitement de fumées d’incinérateur de déchets. Les travaux évaluent, à l’aide d’une installation pilote, la viabilité du captage du CO2 en postcombustion par absorption/désorption avec un solvant à 30 % massique en monoéthanolamine (MEA). Tout d’abord, une synthèse bibliographique identifie les verrous technologiques. Puis, le fonctionnement de l’installation est détaillé. Ensuite, une étude paramétrique a évalué les performances de captage du CO2 et la consommation énergétique du pilote. Enfin, des expériences sur une période de 5 jours ont étudié la résistance chimique du solvant face des gaz de combustion. Les travaux de recherche ont permis une première validation du procédé pour un incinérateur de déchets. / This research is part of a survey designed to establish the viability of the CO2 recovery as a raw material from an industrial waste incinerator.. Several commercial licenses are available to capture CO2 in flue gas, but there are no references for incinerators. This work studies with a pilot the post-combustion CO2 capture from incinerator flue gas using absorption/desorption process with 30 %wt monoethanolamine (MEA). A literature review identifies the technology gaps. Then, the pilot setup was described. A parametric study has evaluated the pilot performance for CO2 capture and energy consumption. Finally, Long runs (5 days) have studied the solvent chemical stability in front of incinerator flue gas. The laboratory experiments show that CO2 capture form incinerator flue gas is possible.

The city is a place of accumulation, production and reproduction of production resources and consumption of goods, but waste typically accumulates outside it. It falls out of our horizon physically and mentally. The waste we produce changes the landscape and transforms the processes on earth without most of us visiting the "places of transformation". The project works with the idea of redirecting the final phase of the production chain back to the place of consumption by producing elements of public space from municipal waste. The presentation of waste leads to an awareness of its amount and degree of consumption. At the same time, waste becomes something much more ambivalent, possibly useful or even beautiful.

In Sweden, there are limits to how much leachable substances waste must contain in order to be deposited as hazardous waste. Fly ash from waste incineration often end up over the limit, mainly due to the chloride content. Fly ash is therefore often deposited abroad. The purpose of this study was to investigate the possibility to handle fly ash locally. To clarify how the law is applied, environmental reports and permit documents from ten waste sites with permission to deposit fly ash were studied. In addition, a literature study was made to review the state of knowledge regarding the treatments of fly ash. The treatment methods are numerous, but are at different levels of commerciality. Among the treatments available there are both physical, chemical, biological, electrical and thermal variants. Many of the treatments (except for carbonation and microbial bioleaching) results in chloride levels below the limits. Several are however unrealistically expensive or generate wastewater with high levels of chloride that would need further treatment. Three plants out of the ten holding permits to deposit fly ash, have exemptions from the limit for chlorides. It's however difficult to see a common reasoning for allowing exemptions. In several cases there are sensitive receiving waters downstream from the landfill. One reason to be dispensed despite this sensitivity, may be the guidance that EPA issued. It is not formulated any specific concerns relating to chlorides. One handles therefore often high levels of chloride in the leachate as a dilution problem, not a leaching problem. / I Sverige finns det gränsvärden för hur mycket utlakningsbara ämnen avfall får innehålla för att kunna deponeras som farligt avfall. Flygaska från avfallsförbränning hamnar ofta över gränsen för vad som får deponeras, främst p.g.a. kloridinnehållet, och askan deponeras därför bl.a. i Norge och Tyskland. Syftet med denna studie var att utreda möjligheten att hantera flygaska lokalt. För att klargöra hur lagstiftningen tillämpas har miljörapporter och tillståndsbeslut från tio avfallsanläggningar med tillstånd att deponera flygaska studerats. Dessutom har en litteraturstudie gjorts av kunskapsläget när det gäller behandling av flygaska för att motverka lakning av klorider. Behandlingsmetoderna är många, men har kommit olika långt i att anses som kommersiella. Bland behandlingarna finns både fysiska, kemiska, biologiska, elektriska och termiska varianter. Många av behandlingarna (med undantag för karbonatisering och mikrobiell bioutlakning) gör att gränsvärden för utlakning av klorider klaras. Många av behandlingarna är dock orealistiskt dyra eller genererar avloppsvatten med höga kloridhalter. Av de tio anläggningar som innehar tillstånd till att deponera flygaska, så har tre även dispens för gränsvärdet för klorider. Utifrån den information som finns i tillståndsbesluten är det mycket svårt att se ett mönster vad gäller bedömningen av de enskilda fallen. I flera fall finns känsliga recipienter nedströms deponin. En anledning till att dispens ges trots denna känslighet kan vara den vägledning som Naturvårdsverket gett ut. Där formuleras inte någon specifik problematik kring klorider, utan andra ämnen är i fokus. Man behandlar därför ofta höga kloridhalter i lakvatten som ett utspädningsproblem, istället för ett utlakningsproblem.

"Les dioxines" (PCDD/F : polychlorodibenzodioxines/furanes) sont des polluants organiques persistants émis dans l'atmosphère, provenant de combustions incomplètes. Cette étude concerne l'oxydation et la pyrolyse du dibenzofurane (DBF) choisie comme molécule modèle des PCDF. La réaction est étudiée dans un réacteur parfaitement agité entre 500 et 950°C, pour un temps de passage de 3 à 5s et à très faible concentration de DBF (~2 ppm) pour se rapprocher des conditions des incinérateurs (UIOM). Les espèces intermédiaires, formées lors de la décomposition du DBF, sont identifiées par GC/MS puis quantifiées par TD/GC/FID. Ces produits sont des dérivés du benzofurane, des composés aromatiques et poly-aromatiques. A partir de ces résultats, un mécanisme cinétique détaillé a pu être développé et validé. Ce mécanisme est ensuite utilisé pour simuler d'autres conditions opératoires et optimiser la zone de postcombustion des UIOM / "Dioxins" (PCDD/F) are persistent organic pollutants which are emitted in the atmosphere by several combustion and thermal processes. The present study concerns the oxidation and the pyrolysis of dibenzofuran which is chosen as a model molecule of polychrorodibenzofurans. The reaction is studied at very low concentration of dibenzofuran (~2 ppm) in a continuous perfectly stirred reactor between 3s and 5s, whereas temperature is ranging from 500°C to 950°C. During dibenzofuran decomposition, several intermediary species are formed; they are identified by GC/MS and then quantified by TD/GC/FID. The main products are derivatives of benzofuran, polyaromatic hydrocarbons and other volatile organic compounds. Taking into account our experimental results and the literature data, we have proposed and validated a detailed mechanism of DBF reaction. This mechanism is used to model the abatement of dioxins by total oxidation in the postcombustion area of a municipal waste incinerator