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Atmospheric ammonia (NH₃(g)) poses an environmental concern mainly due its ability to form fine particulate matter (PM2.5 with a diameter smaller than 2.5 micrometers) in the form of ammonium nitrate (NH₄NO₃) and ammonium sulfate ([NH₄]₂SO₄). These forms of PM2.5 may reduce visibility, contribute to eutrophication through deposition, and be detrimental to human health through inhalation. A more complete understanding of ammonia emissions may bring significant PM2.5 reductions within grasp. According to recent studies, one of the largest contributors to atmospheric ammonia is dairy cattle excreta. In this study, seven lactating Holstein cows were subjected to four feeding trials with diets containing 14.5, 15.5, 17, and 18% crude protein (CP). The first objective was to determine the effect of protein content/intake on ammonia fluxes to the atmosphere from each stage of manure handling at a flush dairy. The second objective was to examine the effect of manure handling itself on ammonia fluxes. We examined four different stages of manure handling: 1. Fresh mixture of urine and feces to represent what may be scraped from a barn floor 2. Diluted mixture of urine and feces to represent what is flushed from a barn floor 3. Solids portion of a diluted mixture of urine and feces to represent what is retained by a solids separator at a dairy 4. Liquid portion of a diluted mixture of urine and feces to represent the permeate from a solids separator at a dairy Ammonia fluxes from scraped manure began low and rose to higher fluxes and peaked at an average of 25 hours after mixing urine and feces. Fluxes from flushed manure showed the same behavior. The average pH values for the scraped and flushed manure were relatively low at 6.87±0.17 and 7.05±0.13, respectively, and unfavorable toward ammonia versus ammonium. Fluxes from the separated solids and liquid manure, whose pH values were higher at 8.70±0.30 and 8.55±0.19, respectively, peaked almost immediately. For a time period of 18 hours after beginning flux measurements from the separated liquid manure, fluxes stayed relatively constant. Compared to hours 0-9, fluxes from the separated solids manure decreased 11% in hours 9-18. These results indicate that ammonia fluxes from the scraped and flushed manure were initially limited by the relatively low pH of the slurries, until they aged and released carbon dioxide, after which fluxes became controlled by temperature. Fluxes from the separated solids and liquid manure, however, were temperature-controlled from the start, as this manure had already undergone some aging and the initial pH was more favorable to ammonia loss. Multivariable regressions predicting the mass of ammonia lost to the atmosphere as a function of total ammoniacal nitrogen (TAN) and temperature (T) show that fluxes from the scraped and flushed manure are very sensitive to temperature compared to the separated solids and liquid manure. The same regressions show that ammonia fluxes from the separated solids and liquid manure are predicted well by TAN and T (R² = 0.906 and 0.812, respectively), indicating that dietary protein manipulation, which affects TAN content of the manure, may have a greater effect in this stage of handling. Regressions predicting the mass of ammonia lost to the atmosphere as a function of crude protein intake show crude protein intake is a poor predictor of the overall ammonia flux from a flush dairy. Low correlation coefficients from these regressions are likely a result of cow-to-cow variability in the effect of crude protein intake on ammonia emissions. Significant reductions in ammonia fluxes are possible; however, they will require new regulations on manure handling at flush dairies or incentives for flush dairies to pursue alternate means of manure handling with low emissions. Dairies can begin attacking the problem of excessive emissions by lowering the dietary protein content for older cows to reduce the mass of TAN excreted in their manure, thereby reducing ammonia fluxes in accordance with Henry's law. Once manure is excreted on the barn floor, dairies must encourage mixing between urine and feces and use the natural acidity of the feces in delaying emissions by converting aqueous ammonia in the urine to ammonium. Dairies can achieve well-mixed slurries by manually mixing the manure or with a sloped floor, channeling urine and feces to a common area. Covering holding tanks containing flushed manure to minimize CO₂ stripping and a rise in pH is one measure that may reduce ammonia fluxes. Finally, requiring nitrification or nitrification and denitrification in on-site storage tanks will biologically convert ammonia to nitrate or nitrogen gas, respectively, reducing fluxes from the separated liquid manure. Although burdensome to dairies, these measures would drastically reduce ammonia emissions from flush dairies. Regulatory agencies may choose to ignore the separated solids manure when considering strategies to reduce ammonia emissions, since ammonia volatilization becomes limited by aqueous ammonia in the first 18 hours following separation. / Master of Science

An extended air sampling program was conducted at an electric-arc secondary steel manufacturing facility using the HI-VOLUME Sampler reference method for suspended particulates. A wind recording device was installed at the facility to provide a continuous record of wind data for correlation with the particulate concentrations collected. Weather data obtained from the National Weather Service were also used. A relationship between wind direction and speed with the levels of particulate matter collected was found indicating areas of significant pollution sources. Wind-pollution roses were constructed showing the frequency distribution of the wind during periods when particulate concentrations were above and below the national ambient air standards. These roses were compared with the atmospheric stability classes for each of those periods. Log-probability plots were constructed for each sampling point and an exponential relationship was found between mean concentrations at each sampler and each sampler's distance from the source. Using this relationship, an estimated emission rate for the facility was calculated. A background level for the area in the vicinity of the facility was found. Some conclusions were that the mean level of concentration decreased exponentially with distance from the source and that the estimated emission rate for the facility was below the maximum allowable by the State Air Pollution Control Board. It was also concluded that, in long term sampling, wind characteristics showed a positive relationship with particulate concentrations. The most significant conclusion was that the emission activity at the steel facility had minimal effect on a sampler located 1,000 yards away. / Master of Science

This research investigates the difference between indoor and outdoor residential fine particulate matter (PM2.5) and explores the feasibility of predicting residential PM2.5 infiltration for use in exposure assessments. Data were compiled from a previous study conducted in Seattle, Washington, USA and a new monitoring campaign was conducted in Victoria, British Columbia, Canada. Infiltration factors were then calculated from the indoor and outdoor monitoring data using a recursive mass balance model. A geographic information system (GIS) was created to collect data that could be used to predict residential PM2.5 infiltration. Spatial property assessment data (SPAD) were collected and formatted for both study areas, which provided detailed information on housing characteristics. Regression models were created based on SPAD and different meteorological and temporal variables. Results indicate that indoor PM2.5 is poorly correlated to outdoor PM2.5 due to indoor sources and significant variations in residential infiltration. A model based on a heating and non-heating season, and information on specific housing characteristics from SPAD was able to predict a large portion of the variation within residential infiltration. Such models hold promise for improving exposure assessment for ambient PM2.5.

Emissions from residential combustion appliances vary significantly depending on the firing behaviours and combustion conditions, in addition to combustion technologies and fuel quality. Although wood pellet combustion in residential heating boilers is efficient, the combustion conditions during start-up and stop phases are not optimal and produce significantly high emissions such as carbon monoxide and hydrocarbon from incomplete combustion. The emissions from the start-up and stop phases of the pellet boilers are not fully taken into account in test methods for ecolabels which primarily focus on emissions during operation on full load and part load. The objective of the thesis is to investigate the emission characteristics during realistic operation of residential wood pellet boilers in order to identify when the major part of the annual emissions occur. Emissions from four residential wood pellet boilers were measured and characterized for three operating phases (start-up, steady and stop). Emissions from realistic operation of combined solar and wood pellet heating systems was continuously measured to investigate the influence of start-up and stop phases on total annual emissions. Measured emission data from the pellet devices were used to build an emission model to predict the annual emission factors from the dynamic operation of the heating system using the simulation software TRNSYS. Start-up emissions are found to vary with ignition type, supply of air and fuel, and time to complete the phase. Stop emissions are influenced by fan operation characteristics and the cleaning routine. Start-up and stop phases under realistic operation conditions contribute 80 – 95% of annual carbon monoxide (CO) emission, 60 – 90% total hydrocarbon (TOC), 10 – 20% of nitrogen oxides (NO), and 30 – 40% particles emissions. Annual emission factors from realistic operation of tested residential heating system with a top fed wood pelt boiler can be between 190 and 400 mg/MJ for the CO emissions, between 60 and 95 mg/MJ for the NO, between 6 and 25 mg/MJ for the TOC, between 30 and 116 mg/MJ for the particulate matter and between 2x10-13 /MJ and 4x10-13 /MJ for the number of particles. If the boiler has the cleaning sequence with compressed air such as in boiler B2, annual CO emission factor can be up to 550 mg/MJ. Average CO, TOC and particles emissions under realistic annual condition were greater than the limits values of two eco labels. These results highlight the importance of start-up and stop phases in annual emission factors (especially CO and TOC). Since a large or dominating part of the annual emissions in real operation arise from the start-up and stop sequences, test methods required by the ecolabels should take these emissions into account. In this way it will encourage the boiler manufacturers to minimize annual emissions. The annual emissions of residential pellet heating system can be reduced by optimizing the number of start-ups of the pellet boiler. It is possible to reduce up to 85% of the number of start-ups by optimizing the system design and its controller such as switching of the boiler pump after it stops, using two temperature sensors for boiler ON/OFF control, optimizing of the positions of the connections to the storage tank, increasing the mixing valve temperature in the boiler circuit and decreasing the pump flow rate. For 85 % reduction of start-ups, 75 % of CO and TOC emission factors were reduced while 13% increase in NO and 15 % increase in particle emissions was observed.

Road Deposited Sediment (RDS) is an important pathway of pollution material in the urban environment. Traditional particulate matter (PM) monitoring methods are typically expensive and time consuming. To date, urban sediment studies have not fully explored the application of mineral magnetic technologies as an alternative to characterise RDS or, perhaps more importantly, their use as particle size proxy. Therefore, this study addresses these issues by determining the extent of any linkages between magnetic properties and the physio-chemical concentrations of RDS. Investigations have focussed on a spatial temporal study (2008-10) of RDS from the City of Wolverhampton (n = 546) and a similar ‘snap-shot’ study of eight selected town and cities across the UK (n = 306), plus a comparison investigation linked to regional monitoring of air sampling units (ASU) (n = 208). A suite of analytical approaches, namely mineral magnetism, laser diffraction, X-Ray Fluorescence spectroscopy (XRF), Scanning Electron Microscopy (SEM) and Loss on Ignition (LOI), were employed to characterize sample properties. Data interrogation identified mainly weak correlations exist between most mineral magnetic parameters and particle size classes (i.e. sand, silt and clay) and respiratory health-related size classes (i.e. PM10, PM2.5 and PM1.0). The few strongest correlations (p <0.001) were found between mineral magnetic concentration and <PM10 parameters. In Wolverhampton this occurred for samples collected during the spring months (March and May), indicating possible seasonal influences on RDS dynamics and sources. Elsewhere in the UK, and at ASU stations, results revealed mainly limited or insignificant (p >0.05) correlations exist between mineral magnetic parameters and particle size. However, for some locations (most notably, London and Scunthorpe), results exhibit signatures perceived to be associated with environmental factors. Detailed multivariate Factor Analysis plots and Geographical Information System (GIS) images have been used to explore these findings further. These illustrate RDS properties of road types (arterial and residential) display significantly different characteristics, with raised mineral magnetic concentrations for arterial roads, compared to lesser concentrations for residential roads, which corresponds to traffic flow data. This is supported by SEM analyses that reveal elevated concentrations of iron oxide spheres in samples collected from arterial roads, which are indicative of inputs from anthropogenic combustion sources. Contextualising these findings within the framework of existing knowledge, a conceptual approach has been presented that explores factors (i.e. sampling area, topography, land use, sediment source and potential mixing), which influence the reliability of using mineral magnetic techniques a particle size proxy. This demonstrates that any increase in the complexity of these factors (sampling area dynamics) can be used to predict the likelihood of being able to employ mineral magnetic measurements as a proxy. To surmise the work overall, despite mineral magnetic technologies offering an inexpensive and rapid means of analysing RDS, its use as a proxy measure for particulate matter appears to be limited by a series of site-related factors but the technique seems to offer valuable insights for pollution source studies.

Particulate matter (PM) is one of the most studied and problematic pollutants due to its toxicity and relati­vely high concentrations. This thesis aims to clarify the main sources and exposures of PM in Tallinn and Tartu, study the associations with health effects, and estimate the extent of those effects with health impact assessment (HIA). It appeared that the main sources of particulate air pollution in Tallinn (the capital of Estonia) and Tartu (the second largest city of Estonia) are local heating and traffic, inclu­ding road dust. In addition to local emissions, particulate levels are affected by transboundary pollution. If the transboundary air masses originated from the Eastern European areas, the concentration as well as the oxidative capacity of fine particles was significantly higher in urban background air in Tartu compared to air masses coming from Scandinavian areas (Paper I). During the last 15 years, traffic increase has been very fast in Tartu. However, due to the improvement in vehicle technology during this period, there has been only a slight increase in concentration of exhaust particles (Paper II). Nevertheless, a greater increase in road dust emissions was detected. A statistically significant relationship between long-term exposure to those traffic induced par­tic­les and cardiac disease in the RHINE (Respiratory Health in Northern Europe) Tartu cohort was shown (Paper III). However, no significant associations with respira­tory health were found. The HIA in Tallinn demonstrated 296 (95% CI = 76–528) premature deaths annually, because of PM (Paper IV). The average decrease in life expectancy was predicted to be 0.64 (95% CI 0.17–1.10) years. However, among risk groups it can be higher. In addi­tion, several cardiovascular hospitalizations are related. The costs to society be­cause of health effects reach up to €150 million annually (95% CI = 40–260) from pre­mature deaths and hospitali­zation constitute an additional €0.3 million (95% CI = 0.2–0.4). The special HIA scenario, when more pollution fuel peat will be used in boiler houses was analysed as well (Paper V). It indicated that peat bur­ning would result in up to 55.5 YLL per year within the population of Tartu. However, the health effects of pollution from current traffic, local heating, and industry are at least 28 times bigger. In conclusion, exposure to PM cause considerable health effects in the form of cardio­pulmo­nary diseases in main Estonian cities.

As the legislation on vehicle emissions is becoming more and more stringent, increasing attention has been paid to the fine particles emitted by diesel and gasoline vehicles. The high number emission of fine particles has been shown to have a large impact on the atmospheric environment and human health. Researchers have shown that gasoline engines, especially Gasoline Direct Injection (GDI) engines, tend to emit large amounts of small size particles compared to Port Fuel Injection (PFI) gasoline engines and diesel engines fitted with Diesel Particulate Filters (DPFs). As a result, the particle number emissions of GDI engines will be restricted by the EU6 legislation. The particulate emission level of GDI engines means that they would face some challenges in meeting the EU6 requirement. This thesis undertakes research in the following area. Firstly, the filtration efficiencies of glass fibre filters were quantified using a Cambustion Differential Mobility Spectrometer 500 (DMS500) to see if all of the particles from the sampled gas can be collected by the filters. Secondly, various valve timings and different injection modes such as double injection with a second injection after compression, single early injection and split early injection were implemented to measure the Particulate Matter (PM) emissions and combustion characteristics of a GDI engine under warm-up operating conditions. Thirdly, the techniques for removing volatile particles were investigated using a catalytic Volatile Particle Remover (VPR) and an Evaporation Tube (ET) with hot air dilution under various test conditions. The results show that for the glass fibre filters tested here, the transmission efficiencies of the particles are very low, indicating that PM sampling using fibre filters is an effective method of studying the particulate emissions from the engine. Particle number emissions using double injection with injection after compression were much higher than those with single injection during the intake stroke. Under 1200 rpm, 110 Nm cold engine operation, no reduction effect on PM emissions was shown by using split intake injection to further facilitate homogeneous mixture formation compared with single intake injection. Valve timings showed moderate effects on particulate emissions. Properly adjusted timing for exhaust valve closure led to reduced particulate emissions by a factor of about 2 and the combustion characteristics were not adversely affected much. The VPR temperature and exhaust residence time did not show much effect on the catalytic VPR performance once the mass flow rate of exhaust was above 0.09 g/s. Generally, the transmission efficiencies of the VPR follow the trends of the scaled PMP counting efficiency specification. Hot air dilution is effective in reducing the small size particles. At 23 nm, the transmission efficiencies are within the error range of the PMP specification. The catalytic VPR and the Evaporation Tube were all found to be effective in reducing the particle number of small size (nucleation mode) particles. Both systems have some particle loss mainly due to the physical effects of diffusion and thermophoresis. Until now, GDI engines have not been optimised for reducing particulate emissions as the focus has been on gaseous emissions and fuel economy. With careful re-optimisation of the catalyst light-off and engine calibration (especially for transients) then there is scope for GDI engines to meet forthcoming emissions legislation.

Neste trabalho propõe-se uma análise da dispersão de material particulado gerado por fontes estacionárias, aplicando ferramentas de Fluidodinâmica Computacional (em inglês Computatonal Fluid Dynamics, CFD), usando um modelo Euleriano para o escoamento e Lagrangeano para as partículas, em estado estacionário no software Fluent. A verificação da modelagem é apresentada em duas sessões, a primeira compreende o estudo do escoamento atmosférico em condições de estabilidade neutra incluindo os efeitos das heterogeneidades do terreno, no caso, um monte de 126m de altura em escala real. Foram comparados diferentes modelos de turbulência: padrão, RNG e parametrizado para o caso atmosférico. Os três modelos apresentaram desempenho semelhante e descrevem satisfatoriamente as tendências dos dados experimentais. A segunda, o modelo lagrangeano baseado no tempo de vida dos turbilhões (em inglês Discrete Random Walk, DRW) foi utilizado para representar a distribuição de concentrações de material particulado em um ambiente confinado. Os resultados numéricos descrevem satisfatoriamente os perfis de concentrações das partículas, porém subestimam os valores na região próxima à parede, o que indicaria que uma melhor aproximação da deposição das partículas deve ser considerada. Após estes estudos, esta abordagem euleriana-lagrangeana foi aplicada ao caso da dispersão de material particulado em condições de atmosfera neutra em uma região do Polo Cerâmico de Santa Gertrudes-SP, local responsável pela maior produção de revestimentos cerâmicos do Brasil. O trânsito de caminhões nas estradas não pavimentadas foi identificado como fonte de material particulado que atinge o perímetro urbano da cidade. Estudaram-se também as contribuições das atividades referentes à exploração das minas de argila e a preparação do solo para uso agrícola, apesar desta última não soma uma carga relevante ao ser comparada com as duas anteriores. Além da influência das fontes mencionadas, fontes de origem industriais localizadas dentro da cidade também foram consideradas no cenário. / In this study an analysis of the dispersion of particulate matter generated by stationary sources is proposed, by applying Computational Fluid Dynamics (CFD) tools, using an Eulerian model for the flow and a Lagrangean model for the particles, under steady-state conditions in the Fluent software. The model validation is presented in two sessions, the first comprises the study of the atmospheric flow under conditions of neutral stability, including the effects of the heterogeneities of the terrain. In this case, the air flow past a 126m high hill in real scale was adopted. Different turbulence models were compared: standard k-?, k-? RNG and parametrized k-?. The three models presented similar performance and described satisfactorily the trends of the experimental data. Subsequently, the Lagrangean model based on the Eddy life time (DRW - Discrete Random Walk) was used to represent the distribution of particulate matter concentrations in a confined environment. The numerical results satisfactorily describe the particle concentration profiles, but underestimate the values in the region near the wall, which would indicate that a better approximation of the particle deposition should be considered. After these studies, this Eulerian- Lagrangean approach was applied to the case of dispersion of particulate material under neutral atmosphere conditions in a region around the city of Santa Gertrudes-SP, where the Ceramic Complex is responsible for the largest production of ceramic tiles in Brazil. Transit of trucks on unpaved roads has been identified as a source of particulate matter that reaches the urban perimeter of the city. The contributions of the activities related to mining and the preparation of the soil for agricultural use were also studied, although this last one does not add a significant load when compared with the two previous ones. In addition to the influence of the mentioned sources, industrial sources located inside the city also contribute to the scenario.