In this study, the formation mechanisms, distribution characteristics, and potential environmental risks of hazardous air pollutants from industrial-scale waste incineration processes were investigated. First, to clarify the dominant formation mechanism of polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) in a hazardous waste (HW) incinerator, three tests were designed by adding different precursors in phenol-containing raw materials. With the addition of p-dichlorobenzene, PCDD/F levels at the quenching tower outlet were ten times higher than levels observed at the inlet. This indicates that the quenching tower failed to suppress the formation of PCDD/Fs and surface-mediated precursor reaction is the dominant formation mechanism in low-temperature stages. Besides, adsoprtive memory effect in air pollution control devices (APCDs) also led to high PCDD/F emissions. These findings suggest that to control PCDD/F emissions, strict regulation of chlorine contents in feed materials and frequent cleaning of APCDs are necessary. Meanwhile, single particles and solid residues were collected from the same HW incinerator. Morphologies and elemental compositions of particles in flue gas and indoor air were characterized by transmission electron microscopy-energy dispersive X-ray spectrometry (TEM-EDS). Eight types of single particles were classified, as organic, soot, K-rich, S-rich, Na-rich, Fe-rich, mineral and fly ash particles. The heavy metal partitioning behavior study suggested that Hg, Cd and Pb were mainly enriched in fly ash through evaporation, condensation, and adsorption; while Cr, Cu, Mn, and Ni were mostly remained in the bottom ash due to their low volatilities. In addition, the study also investigated environmental behaviors of certain characteristic pollutants. Thrity-two soil samples surrounding a cement plant co- processing HW were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 12 heavy metals. Ten samples were selected for PCDD/Fs analysis. The highest concentration of PCDD/Fs occurred 1200 meters downwind from the cement plant. Levels of ∑16 PAHs ranged from 130.6 to 1134.3 μg/kg in soil. Source identification analysis suggested that the cement plant was the most likely source of PAH contamination. The concentrations of Cd and Hg were on average two times and six times higher than background values, respectively. Both incremental lifetime cancer risk model (ILCR) for PAHs and potential ecological risk index (RI) for heavy metals indicate potential risks to the population and the environment surrounding the cement plant. Last, to identify whether waste incineration is a major source for airborne environmentally persistent free radicals (EPFRs), tree leaf samples were collected from 120 sites surrounding four waste incinerators and one urban area. EPFR concentrations on leaves ranged from 7.5 × 10 16 to 4.5 × 10 19 spins/g. For the 10 N.D. samples, they were all collected from areas inaccessible by vehicles. Although previous work has linked atmospheric EPFRs to waste incineration, the evidence in this study suggests that vehicle emissions, especially from heavy-duty vehicles, are the main sources. According to our estimation, over 90% of the EPFRs deposited on tree leaves might be attributed to automotive exhaust emissions, as a synergistic effect of primary exhausts and degradation of aromatic compounds in road dust

In this study, the formation mechanisms, distribution characteristics, and potential environmental risks of hazardous air pollutants from industrial-scale waste incineration processes were investigated. First, to clarify the dominant formation mechanism of polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDD/Fs) in a hazardous waste (HW) incinerator, three tests were designed by adding different precursors in phenol-containing raw materials. With the addition of p-dichlorobenzene, PCDD/F levels at the quenching tower outlet were ten times higher than levels observed at the inlet. This indicates that the quenching tower failed to suppress the formation of PCDD/Fs and surface-mediated precursor reaction is the dominant formation mechanism in low-temperature stages. Besides, adsoprtive memory effect in air pollution control devices (APCDs) also led to high PCDD/F emissions. These findings suggest that to control PCDD/F emissions, strict regulation of chlorine contents in feed materials and frequent cleaning of APCDs are necessary. Meanwhile, single particles and solid residues were collected from the same HW incinerator. Morphologies and elemental compositions of particles in flue gas and indoor air were characterized by transmission electron microscopy-energy dispersive X-ray spectrometry (TEM-EDS). Eight types of single particles were classified, as organic, soot, K-rich, S-rich, Na-rich, Fe-rich, mineral and fly ash particles. The heavy metal partitioning behavior study suggested that Hg, Cd and Pb were mainly enriched in fly ash through evaporation, condensation, and adsorption; while Cr, Cu, Mn, and Ni were mostly remained in the bottom ash due to their low volatilities. In addition, the study also investigated environmental behaviors of certain characteristic pollutants. Thrity-two soil samples surrounding a cement plant co- processing HW were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons (PAHs) and 12 heavy metals. Ten samples were selected for PCDD/Fs analysis. The highest concentration of PCDD/Fs occurred 1200 meters downwind from the cement plant. Levels of ∑16 PAHs ranged from 130.6 to 1134.3 μg/kg in soil. Source identification analysis suggested that the cement plant was the most likely source of PAH contamination. The concentrations of Cd and Hg were on average two times and six times higher than background values, respectively. Both incremental lifetime cancer risk model (ILCR) for PAHs and potential ecological risk index (RI) for heavy metals indicate potential risks to the population and the environment surrounding the cement plant. Last, to identify whether waste incineration is a major source for airborne environmentally persistent free radicals (EPFRs), tree leaf samples were collected from 120 sites surrounding four waste incinerators and one urban area. EPFR concentrations on leaves ranged from 7.5 × 10 16 to 4.5 × 10 19 spins/g. For the 10 N.D. samples, they were all collected from areas inaccessible by vehicles. Although previous work has linked atmospheric EPFRs to waste incineration, the evidence in this study suggests that vehicle emissions, especially from heavy-duty vehicles, are the main sources. According to our estimation, over 90% of the EPFRs deposited on tree leaves might be attributed to automotive exhaust emissions, as a synergistic effect of primary exhausts and degradation of aromatic compounds in road dust

Per- and polyfluoroalkyl substances, PFAS, are a manufactured group of chemicals that have been found to be toxic to humans and the environment. Exposure to PFAS may include birth defects for infants as well as an increased risk of cancer.  Due to PFAS exceptional traits of repelling water and oil, it has commonly been used in products such as cleaning agents, clothing, and coating for furniture. Thus, PFAS reaches the environment through deposition on landfills containing residual as well as industrial waste. Another main source of contamination is aqueous firefighting foam (AFFF) which has led to areas where military and firefighters have been practicing commonly having a high concentration of PFAS in the soil and surrounding environment. PFAS has also been found to accumulate in wastewater treatment plants. It’s partly due to its water repelling traits that PFAS has been spread efficiently over the world and has been detected in remote areas, such as Greenland. Moreover, they are persistent as they don’t naturally degrade, which has led to them being referred to as “forever chemicals”.   As of today, the main products for adsorption of PFAS are activated carbon as well as ion exchange resins, with activated carbon being the most common. The drawbacks with activated carbons are that even though they have high adsorption capacity they are non-selective, meaning that it adsorbs many other particles as well as PFAS. They are also not very effective on short-chained PFAS. Ion exchange resins are considered more selective as well as better at adsorbing short-chain PFAS. Both active carbon and ion exchange resins are expensive and require regeneration, which can only be performed so many times before they have to be disposed of.  The objectives of this master thesis were to test three adsorbents for PFAS, study incineration of PFAS in an environment similar to Swedish incineration plants as well as perform a cost analysis that ranges from production to management of ashes. The adsorbents tested are called Granular peat (float adsorb), Iron peat, and PEI-GTMAC-Pinebark (PG-PB). A batch test was performed with wastewater containing 25 mg/L PFAS on L/S 10 and 100 for the granular peat and iron peat and on L/S 100 and 1 000 for PG-PB. After the batch test, the adsorbents were incinerated at 850°C and 1 100°C, and a TGA analysis was performed in order to detect if fluorine was released during the incineration of the adsorbents.  The adsorbents tested adsorbed considerably less PFAS than the commercially available activated carbon and ion exchange resins. Of the tested adsorbents, PG-PB was the most effective adsorbent followed by iron peat, which adsorbed around half the amount of PFAS compared to PG-PB. Peat adsorbed the least amount, which was around one-third of PG-PB. Metal analysis of the wastewater showed that it contained a considerable amount of sulfur as well as sodium among other metals. As PG-PB has previously been used as an adsorbent for sulfate, the low adsorption capacity for PFAS may be due to competition with other cations for adsorption surface on the adsorbents. However, the concentration of sulfur did not change after the batch test with adsorbents, which means that the reason for the low adsorption capacity is not that sulfur occupies the surface of the adsorbents. Other metals, especially the cations, might have an impact and did change during the batch test with the adsorbents, but due to not enough data, no conclusion could be drawn. During incineration of peat, 42.6 g/kg ash was produced at 850°C and 53.3 g/kg ashes were produced while incinerated at 1100°C. Meanwhile, iron peat produces slightly more ashes with 65 g/kg ashes produced at 850°C and 63.8 g/kg ash produced during incineration at 1100°C. Pine bark was estimated to produce around 7.4 kg/g of ashes based on available literature. No PFAS was detected in the ashes. The gas composition from the TGA suggests that PFAS are emitted as flue gas with water during heating of the adsorbent. However, as incineration plants in Sweden are preheated, no conclusion of the destruction/volatile escapee of PFAS in a real incineration plant can be drawn due to different conditions.

<p>The amount of waste in the world increases every year due to an improved living standard andgrowing population. The problem is especially large in poor countries where the ability tohandle the waste is limited due to financial and management problems. If instead wastematerial is seen as a resource it can help reduce the amount of waste on landfill. Byincinerating waste and recover the energy it would also help reducing greenhouse gasemissions from landfill and give electric and thermal energy.Chisinau Municipality in the Republic of Moldova today lacks several important parts fora satisfying waste management. Today most of the waste generated in Chisinau municipalityends up at the municipality landfill. The current contract to use the landfill expires on the 31December 2010, if the municipality won’t be able to renew the contract they have to look forother ways to deal with the waste problem. As the dominating source for energy in Chisinau isimported natural gas, an effective way to reduce the use of gas for electricity and thermalenergy production would be to use waste material for incineration with energy recovery.Therefore, the goal with this thesis is to evaluate the possibility to extract energy from coincinerationof sewage sludge and waste material generated in Chisinau. To reach this goal thesituation in Chisinau where studied on site for two months, quantities and composition of thewaste material was investigated. Based on the data gathered on the waste, a suitabletechnology for the waste-to-energy (WTE) plant is proposed. The proposal is made based onthe assumption that a WTE plant would not be established until 2025.The result shows that the waste material in Chisinau can be used for co-incineration ofwaste and sludge. The calorific value of the waste material was determined to 7.87 MJ per kg.The suggested WTE plant has the total power of 138 MW, the result based on that all wastematerial available 2025 are incinerated. Annually this makes it possible to recover 1152 TJ(320 GWh) electric power and 2650 TJ (736 GWh) heat, based on 8000 operating hoursannually.Even if a WTE plant sounds like a good investment it is a long time before a plant couldoperational. Much is to be made in the waste management to have well-functioninginfrastructure that will work together with an incineration plant. Furthermore, the data used inthis study regarding the quantities is very uncertain and further studies in affected areas arenecessary before a WTE plant can be established.</p> / <p>Den totala mängden avfall i världen ökar varje år som följd av ökad folkmängd ochlevnadsstandard. Problemet är extra påtagligt i fattiga länder med begränsade ekonomiskaresurser för att ta hantera avfallet. Om avfallet istället skulle ses som en resurs skulle detkunna reducera andelen avfall som läggs på deponi. Genom att förbränna avfallet medenergiåtervinning skulle också växthusgaserna från deponering minska och samtidigt geelektrisk och termisk energi.Chisinau kommun i Republiken Moldavien saknar idag flera vitala delar iavfallshanteringen. Idag slutar den största delen av avfallet som produceras i Chisinaukommun på den kommunala deponin. Kontraktet för att använda deponin löper ut den sistadecember 2010, om Chisinau kommun inte tillåts förnya kontraktet är det nödvändigt att sesig om efter nya lösningar för avfallshanteringen. Eftersom den dominerande källan för energii Chisinau är importerad gas, skulle ett effektivt sätt att reducera gasanvändningen vid el ochtermisk energiproduktion att förbränna avfall med energiåtervinning.Av den orsaken är målet med studien att utvärdera möjligheterna att utnyttjasamförbränning med energiåtervinning av avfall och avloppsslam från Chisinau kommun. Föratt nå detta mål har den nuvarande situationen i Chisinau kommun studerats på plats under tvåmånaders tid, detta för att undersöka vilka mängder avfall som årligen produceras och huravfallets fraktionsfördelning ser ut. Baserat på de data som samlats in föreslogs en lämpligavfallsförbränningsanläggning. Förslaget är baserat på antagandet att enavfallsförbränningsanläggning inte är etablerad förrän tidigast 2025.Resultatet visar att det är möjligt att samförbränna avloppsslam och avfall i Chisinau. Detkalorimetriska värmevärdet för avfallet och slammet har bestämts till 7.87 MJ per kg. Det irapporten presenterade förslag på kraftvärmeverk för avfallsförbränning kommer att ha entotal effekt av 138 MW, resultatet är baserat på att allt tillgängligt kommunalt avfall 2025förbränns. Kraftvärmeverket beräknas årligen utvinna TJ (320 GWh) elektrisk energi och2650 TJ (736 GWh) termisk energi, beräknad på 8000 drifttimmar årligen.Även om en avfallsförbränningsanläggning låter som en god investering så ligger detlångt fram i tiden innan en sådan anläggning är möjlig att etablera. Först måste en brafungerande infrastruktur som fungerar tillsammans med avfallsförbränningsanläggningenupprättas. Vidare bör poängteras att de data som använts i denna studie gällandeavfallsmängder är ytterst osäkra och ytterligare studier inom området krävs innan enavfallsförbränningsanläggning kan etableras.</p>

Graduation date: 1995

Biomass-fed cogeneration units and waste incinerators have the advantages of producing efficiently heat and power and of reducing the amount of CO2 emitted per produced energy. However, they produce toxic polychlorinated VOCs (dioxins), CO and NOx. This thesis aims at developing a catalytic system for the total oxidation of chlorinated VOCs that: i) convert efficiently chlorinated VOCs below 250 °C and ii) resist to the exhaust co-pollutants (H2O, CO, NOx). Moreover, this thesis aims at having a complete understanding of the catalytic mechanism. Part I demonstrated that VOx/TiO2 based catalysts are very efficient in the total oxidation of chlorobenzene (taken as a model molecule). In particular, they proved to be highly resistant against deactivation. Moreover, Part I established that the addition of secondary phases producing VOx-WOx/TiO2 or VOx-MoOx/TiO2 induces a synergetic effect that improves the performances. Furthermore, the replacement of a classical TiO2 by a sulfated one improves the catalytic activity. In Part II, the investigation of the co-pollutants influence on the catalysts performances demonstrated their quite good resistance. Indeed, the presence of CO does not induce any deactivation of the catalysts while NOx induces a huge improvement of the catalysts ability to destroy chlorinated VOCs. This beneficial effect is explained by the in situ production of a strong oxidant (NO2) that speeds up the reoxidation of the reduced VOx sites. Nevertheless, H2O vapor can affect negatively the catalyst activity when present in a high concentration. Part III, by revisiting catalytic and characterization results exposed in Part I and II, demonstrated that the catalytic mechanism proceeds in four steps: i) adsorption of chlorinated VOCs on Brønsted sites, ii) VOx redox sites give some of their lattice oxygen atoms to oxidize the aromatic ring producing H2O and COx, iii) reoxidation of the VOx reduced sites thanks to the gas stream oxidant (O2) and iv) retrieving of the chlorine from the surface. The second and third steps compose a Mars and van Krevelen mechanism and the third one is the mechanism rate limiting step. Our work shows that the performances can be improved by tuning the redox properties of the VOx phases: i) improvement of the reducibility and ii) stabilization of the vanadium oxidation level above a limit value, estimated around 4.87.

The amount of waste in the world increases every year due to an improved living standard andgrowing population. The problem is especially large in poor countries where the ability tohandle the waste is limited due to financial and management problems. If instead wastematerial is seen as a resource it can help reduce the amount of waste on landfill. Byincinerating waste and recover the energy it would also help reducing greenhouse gasemissions from landfill and give electric and thermal energy.Chisinau Municipality in the Republic of Moldova today lacks several important parts fora satisfying waste management. Today most of the waste generated in Chisinau municipalityends up at the municipality landfill. The current contract to use the landfill expires on the 31December 2010, if the municipality won’t be able to renew the contract they have to look forother ways to deal with the waste problem. As the dominating source for energy in Chisinau isimported natural gas, an effective way to reduce the use of gas for electricity and thermalenergy production would be to use waste material for incineration with energy recovery.Therefore, the goal with this thesis is to evaluate the possibility to extract energy from coincinerationof sewage sludge and waste material generated in Chisinau. To reach this goal thesituation in Chisinau where studied on site for two months, quantities and composition of thewaste material was investigated. Based on the data gathered on the waste, a suitabletechnology for the waste-to-energy (WTE) plant is proposed. The proposal is made based onthe assumption that a WTE plant would not be established until 2025.The result shows that the waste material in Chisinau can be used for co-incineration ofwaste and sludge. The calorific value of the waste material was determined to 7.87 MJ per kg.The suggested WTE plant has the total power of 138 MW, the result based on that all wastematerial available 2025 are incinerated. Annually this makes it possible to recover 1152 TJ(320 GWh) electric power and 2650 TJ (736 GWh) heat, based on 8000 operating hoursannually.Even if a WTE plant sounds like a good investment it is a long time before a plant couldoperational. Much is to be made in the waste management to have well-functioninginfrastructure that will work together with an incineration plant. Furthermore, the data used inthis study regarding the quantities is very uncertain and further studies in affected areas arenecessary before a WTE plant can be established. / Den totala mängden avfall i världen ökar varje år som följd av ökad folkmängd ochlevnadsstandard. Problemet är extra påtagligt i fattiga länder med begränsade ekonomiskaresurser för att ta hantera avfallet. Om avfallet istället skulle ses som en resurs skulle detkunna reducera andelen avfall som läggs på deponi. Genom att förbränna avfallet medenergiåtervinning skulle också växthusgaserna från deponering minska och samtidigt geelektrisk och termisk energi.Chisinau kommun i Republiken Moldavien saknar idag flera vitala delar iavfallshanteringen. Idag slutar den största delen av avfallet som produceras i Chisinaukommun på den kommunala deponin. Kontraktet för att använda deponin löper ut den sistadecember 2010, om Chisinau kommun inte tillåts förnya kontraktet är det nödvändigt att sesig om efter nya lösningar för avfallshanteringen. Eftersom den dominerande källan för energii Chisinau är importerad gas, skulle ett effektivt sätt att reducera gasanvändningen vid el ochtermisk energiproduktion att förbränna avfall med energiåtervinning.Av den orsaken är målet med studien att utvärdera möjligheterna att utnyttjasamförbränning med energiåtervinning av avfall och avloppsslam från Chisinau kommun. Föratt nå detta mål har den nuvarande situationen i Chisinau kommun studerats på plats under tvåmånaders tid, detta för att undersöka vilka mängder avfall som årligen produceras och huravfallets fraktionsfördelning ser ut. Baserat på de data som samlats in föreslogs en lämpligavfallsförbränningsanläggning. Förslaget är baserat på antagandet att enavfallsförbränningsanläggning inte är etablerad förrän tidigast 2025.Resultatet visar att det är möjligt att samförbränna avloppsslam och avfall i Chisinau. Detkalorimetriska värmevärdet för avfallet och slammet har bestämts till 7.87 MJ per kg. Det irapporten presenterade förslag på kraftvärmeverk för avfallsförbränning kommer att ha entotal effekt av 138 MW, resultatet är baserat på att allt tillgängligt kommunalt avfall 2025förbränns. Kraftvärmeverket beräknas årligen utvinna TJ (320 GWh) elektrisk energi och2650 TJ (736 GWh) termisk energi, beräknad på 8000 drifttimmar årligen.Även om en avfallsförbränningsanläggning låter som en god investering så ligger detlångt fram i tiden innan en sådan anläggning är möjlig att etablera. Först måste en brafungerande infrastruktur som fungerar tillsammans med avfallsförbränningsanläggningenupprättas. Vidare bör poängteras att de data som använts i denna studie gällandeavfallsmängder är ytterst osäkra och ytterligare studier inom området krävs innan enavfallsförbränningsanläggning kan etableras.

With the rapid and large increase of waste quantities, China, surpassed the USA as the world’s largest municipal solid waste (MSW) generator since 2004. The phenomena and critical issues of MSWM in China inspired this paper to investigate and analyse the MSWM in an urban area of China. Comparing with the increasing rates of MSW generation, little has been done concerning the municipal solid waste management (MSWM). Not only the local government and authorities are responsible for the MSWM, but also the individuals are playing a significant role in MSWM. An integrated waste management system should be built in order to improve the holistic MSW system and reduce the waste production. The aim of the study is to investigate and analyse the current status and problems of MSWM in an urban area of China and to analyse to what extent a viable reduction of the MSW can be implemented and management systems to be improved in the near future. In this study, two case studies of Shanghai and Linköping are employed and compared to explore the challenges and potentials for improving the MSWM system in China. The result indicated that inadequate facilities and infrastructure, less advanced technology, insufficient public participation, low awareness of environmental protection, problems in policy and laws are the major barriers for the improvement of MSWM. Involving international environmental cooperation activities, planning a sustainable and comprehensive policy and framework for MSWM, introducing economic incentive approaches, promoting the capacities of waste management technologies, raising public environmental awareness are believed to be viable solutions to improve the MSWM system in China.

Waste-to-Energy concept becomes increasingly popular from the perspectives of the waste management and alternative energy. South Africa, which is a country heavily dependent on the fossil fuel, can explore the opportunities of Waste-to-Energy in order to deal with increasing amount of waste generated while reducing what is deposited at non-engineered landfills, thereby increase the renewable energy share. This prefeasibility study attempts to identify Waste-to-Energy potentials in Gauteng provinceso as to develop a Waste-to-Energy facility under the new renewable Independent Power Producer procurement programme of South Africa. The analysis identifies abundant Wasteto-Energy incineration and landfill gas opportunities linked with municipal solid waste in twomunicipalities. The prefeasibility study further evaluates environmental, socio-economic aspects of Waste-to-Energy initiative. The financial viability of a Waste-to-Energy incineration facility with the Feed-in-Tariff proposed by the government of South Africa isalso detailed analysed.

No description available.