Emission factors (EFs) and results from dispersion models are key components in the air pollution regulatory process. The EPA preferred regulatory model changed from ISCST3 to AERMOD in November, 2007. Emission factors are used in conjunction with dispersion models to predict 24-hour concentrations that are compared to National Ambient Air Quality Standards (NAAQS) for determining the required control systems in permitting sources. This change in regulatory models has had an impact on the regulatory process and the industries regulated. In this study, EFs were developed for regulated particulate matter PM10 and PM2.5 from cotton harvesting. Measured concentrations of TSP and PM10 along with meteorological data were used in conjunction with the dispersion models ISCST3 and AERMOD, to determine the emission fluxes from cotton harvesting. The goal of this research was to document differences in emission factors as a consequence of the models used. The PM10 EFs developed for two-row and six-row pickers were 154 + 43 kg/km2 and 425 + 178 kg/km2, respectively. From the comparison between AERMOD and ISCST3, it was observed that AERMOD EFs were 1.8 times higher than ISCST3 EFs for Emission factors (EFs) and results from dispersion models are key components in the air pollution regulatory process. The EPA preferred regulatory model changed from ISCST3 to AERMOD in November, 2007. Emission factors are used in conjunction with dispersion models to predict 24-hour concentrations that are compared to National Ambient Air Quality Standards (NAAQS) for determining the required control systems in permitting sources. This change in regulatory models has had an impact on the regulatory process and the industries regulated. In this study, EFs were developed for regulated particulate matter PM10 and PM2.5 from cotton harvesting. Measured concentrations of TSP and PM10 along with meteorological data were used in conjunction with the dispersion models ISCST3 and AERMOD, to determine the emission fluxes from cotton harvesting. The goal of this research was to document differences in emission factors as a consequence of the models used. The PM10 EFs developed for two-row and six-row pickers were 154 + 43 kg/km2 and 425 + 178 kg/km2, respectively. From the comparison between AERMOD and ISCST3, it was observed that AERMOD EFs were 1.8 times higher than ISCST3 EFs for absence of solar radiation. Using AERMOD predictions of pollutant concentrations off property for regulatory purposes will likely affect a source?s ability to comply with limits set forth by State Air Pollution Regulatory Agencies (SAPRAs) and could lead to inappropriate regulation of the source.

ABSTRACT Although the fractions of station-days that the Pollutant Standard Index (PSI) exceed 100 (also referring to the episodes) in Kaohsiung City showed a decline trend from about 10.3% in 1995 to about 5.5% in 2002, the percentage of particulate PM10 events showed a increase trend: from 1.0 % in 2002 to 2.9 % in 2004. This study first statistically summarized the trends of PM10 concentrations using box plots for four air-quality monitoring stations in Kaohsiung during the period of 1997 to 2004, together with the t-test and F-test. The Comprehensive Air Quality Model with extensions (CAMx model) was then applied to analyze the source and the cause of the PM10 events. The monthly averages of PM10 concentrations at four air-quality monitoring stations were 72.9 ¡V 81.7 £gg/m3 during the period of 1997 to 2004, highest at Hsiung-Kong and lowest at Nan-Chie. The long-term trend analyses show slightly decline results for yearly-averaged PM10 concentrations (1.05% at Nan-Chie, 1.38% at Tzuo-Yin, 1.51% at Chien-Chin, and 1.91% at Hsiung-Kong). During 1997 to 2004, the PM10 episodes occurred most frequently, while the numbers of PM10 episodes decreased from south to north (i.e., Hsiung-Kong > Chien-Chin > Tzuo-Yin > Nan-Chie). The statistical tests using t-test for the mean and F-test for the variance with 95% confidence level show that the probability that the hourly PM10 concentrations differ insignificantly among the four stations is only about 42%. That is, the spatial difference of pollutant concentrations among four air-quality monitoring stations is rather significant in Kaohsiung. The CAMx simulations show that contributions to ambient PM10 from stationary source is about 38.9% (NOx: 24.7%; SO2: 14.2%), 8.8% from mobile source (NOx: 7.4%; SO2: 1.4%), and 0.9% from fugitive emissions (SO2: 0.9%) in Kaohsiung. The contributions to ambient PM10 from the emissions in Kaohsiung Harbor are about 3.5%. Keywords: Particulate matter, Trend analysis, Statistical test, CAMx model.

Previous studies have shown that the continental shelf and slope area off northeastern Taiwan is a region where the material exchange processes between the East China Sea and open ocean are most rigorous under the influences of the Kuroshio and the monsoons. In order to understand the topographic effects on the particulate flux and the transport path of the settling particles in this region, this study has conducted a series of field measurements using time-series sediment traps and current meters as tools. The temporal and spatial variations on the current, the particulate flux and the particle-size distribution as well as the activity and flux of 210 Pb and 210 Po are presented in this thesis. The biological productivity and the runoff of main rivers from Taiwan were not correlated with the particulate fluxes in our study area. However, the variations of the particulate flux in the canyon and on the slope areas were clearly affected by the tidal currents, showing good positive correlation with their amplitudes. The particulate, 210 Pb and 210 Po fluxes all showed an increase toward the ocean bottom but a decrease away from the shore, suggesting that the transports of particle and particle reactive elements were strongly influenced by the lateral transport process in the study area. Highest fluxes were observed in the Mien-Hua Canyon(MHC) and the lower slope southwest of the canyon. Intermediate values were observed in the South Okinawa Trough and the North Mien-Hua Canyon(NMHC). The intercanyon slope and the shallow traps in the NMHC had lowest values. The particulates and particle reactive elements were transported out of the shelf or upper slope area essentially through the MHC toward the slope southwest of the canyon. The NMHC and the intercanyon area were not major pathways for these materials. The fluxes of particle, 210 Pb and 210 Po in the study area were generally at least an order of magnitude greater than those observed from other continental margins in the world, except for the lowest values at the intercanyon station and the shallow water in the NMHC. Thus the continental margin off northeastern Taiwan is one of the most important areas for material exchanges with open oceans in the world. The trapped particulates were mainly silt with variable sand fractions. High sand contents were observed in the MHC and the lower slope southwest of the canyon, the intermediate values were in the outlet of the MHC and the NMHC, and the lowest in the South Okinawa Trough. This shows that the sand content decreases awayfrom the shore. On the contrary, silt and clay fractions in percent increase away from the shore. Under the influence of tidal currents, the settling sand particles in the MHC and its adjacent lower slope were laterally transported from resuspended sandy sediments of the continental shelf and upper slope area adjoining the head of the MHC. The fluxes of sand, silt and clay all decreased toward the South Okinawa Trough but increased toward the bottom. This particle-size distribution pattern also reflected the effect of lateral transport process in the study area. Variations of the 210 Pb activity in this study area were generally correlated inversely with the particulate flux and the sand content, indicating the effect of dilution of the mass flux and the sand content, but were positively correlated with the silt and clay contents because they were major 210 Pb scavengers. No apparent correlations of 210 Po with the mass flux and the three particle-size fractions were observed, suggesting that the variation of 210 Po activity was not related to the mass fluxes or the three particle-size fractions. High 210 Pb activities were found to be associated with high contents of POC, Mn and Fe. Correlations of 210 Pb with both Mn and Fe indicate that the oxide and hydroxide precipitates of Mn and Fe supplied from sediments on the continental shelf, upper slope area and submarine hydrothermal activities might serve as important mechanisms for enhanced 210 Pb scavenging. The relationship between the 210 Pb activity and the POC content might reflect either the settling mode of the fine particles incorporated with fecal pellets or aggregates, or sharing the same source with fine particles. The variatio ns of 210 Po activity were not correlated with Mn, Fe, major components or biogenic components, implying that the association of 210 Po with biogenic components might be masked by the enormous terrigenous materials. Except for the upper-trap samples collected at the intercanyon slope and the NMHC, the 210 Po activity was lower than the 210 Pb activity with 210 Po/210 Pb ratios less than unity. Based on comparisons of 210 Pb and 210 Po with relevant parameters and references of past studies, we can propose several possible mechanisms to explain why the ratios were less then unity: 1. 210 Pb was preferentially scavenged by advecting and settling particulates of terrigenous origin. 210 Po, known to be biophilic, might remain associated with the suspended organic particulates which could be dissolved or not settling. Moreover, the oxide and hydroxide precipitates of Mn and Fe in the study area would further enhance the scavenging of 210 Pb. 2. The particulates in suspension were favorable for differentiation between 210 Pb and 210 Ponuclides while those settled in sediments would allow them to grow toward the secular equilibrium. Therefore, the trapped particulates might be in frequent suspension and short in deposited sediments during their lateral transport. 3. The 210 Pb supplied from the East Asia aerosol in large quantity was accumulated in water column abd carried by the Kuroshio to the study area. The intrusion and eddies of Kuroshio off northeastern Taiwan could bring large amount of 210 Pb into the region of continental shelf and slope, allowing particulates to scavenge 210 Pb more effectively from the surrounding water. The upper trap in the NMHC and that in the intercanyon site yield lowest particulate flux but highest POC content. With less terrigenous material and more biogenic components in these samples, 210 Po/210 Pb ratios were greater than unity and variations of 210 Pb activity were hardly correlated with those of POC contents but were inversely correlated with those of Mn contents. However, the 210 Po activities of upper trap at the intercanyon site were well positively correlated with POC and PIC contents, indicating effects of the fresh biogenic particles. Based on the mass balance calculations of particulate and 210 Pb fluxes, current data and other related data gathered in this study, we may infer the sedimentation dynamics and transport path of the settling particles below 300m depth in the study area. Under the influence of tidal oscillation, terrigenous sediments on the shelf and the shelf break as well as the upper slope would be resuspended and carried into the MHC and transported further away. Most of the sand particles would deposit in the canyon while part of the silt and clay would be transported to the South Okinawa Trough directly and the rest to the lower slope southwest of the MHC. The particulate flux at the lower slope southwest of MHC might also have a portion of particulates swept from the upper slope by the Kuroshio eddies. As the NMHC and the intercanyon sites are located in the central area of the Kuroshio eddies, the particulates from the continental shelf and upper slope area would be blocked, resulting in very low particulate fluxes. High particulate fluxes observed in the lower NMHC trap should largely be due to resuspension of the sediments from the banks of the canyon.

Abstract This study elucidates the processes that may determine the distributions of Mn and other trace metals on the slope of the southern Okinawa Trough. In addition to salinity and temperature, large-volume seawater samples were collected for analyzing dissolved manganese (DMn), particulate manganese (PMn), suspended, particulate organic carbon (POC), pH and dissolved CO2 (TCO2 ) during June-July of 1998, 1999 and 2000. Concentrations of DMn and PMn in a transect decrease generally seaward from the shelf break. However, anomalous distributions of DMn and PMn occur usually between 600 m and 900 m in many deep profiles. Such distribution patterns are probably influenced by the lateral transport of metals released from slope sediments or from the plumes of submarine venting systems. For example, dissolved manganese generally decreases with depth in the oxygenated condition, but in the study area unusual high DMn concentrations were observed commonly at depth 400 m, 600 m, 800 m and 1200 m. The unusual Mn signals become weak, in general, from the South Mien-Hua Canyon to the North Mien-Hua Canyon. The higher concentration of PMn sometimes was observed in deep stations than in shallow stations at the same depth implying that processes other than lateral transport may account for the distributions. Images obtained from EK-500 showed that submarine venting systems exist in anomalous Mn distribution areas. Anomalous distributions of PMn and Kd match DMn unusual distributions very well. Besides, the distribution of TSM is closely related to PMn distributions (R=0.433, p=0.01). Although the distribution of pH data appears to be normal, total alkalinity and total CO2 display anomalous distributions coincidently with those Mn unusual distributions. Meanwhile, the ratio (PMn/PAl) is higher for those unusual Mn distributions, and this is likely the effect of submarine venting.

Mit einer mobilen Probenahme- bzw. Messeinrichtung untersuchte das Institut für Luft- und Kältetechnik Dresden (ILK) im Auftrag des LfULG diffuse Staubemissionen in einer Bauschuttrecyclinganlage. Neben der mobilen Messung mit dem Partikelmessgerät APS 3321 kamen stationäre Messeinrichtungen (Impaktoren u. a.) am Messort zum Einsatz. Im Ergebnis wurden repräsentative Feinstaub- sowie Quarzstaubimmissionen für eine Bauschuttrecyclinganlage ermittelt. In einem weiteren Schritt wurden die Messergebnisse nachgerechnet. Geprüft wurde, ob mit einer Immissionsprognose nach TA Luft auf Basis von Emissionsfaktoren nach VDI 3790 Blatt 3, ähnliche Ergebnisse ermittelt werden. Anhand der durchgeführten Rechnungen wird eingeschätzt, dass die berechneten Werte in der Regel über den Messergebnissen, aber mit einer akzeptablen Toleranz, liegen. Bei Anpassung der Rechenparameter an die Betriebsbedingungen vor Ort wird eine relativ gute Übereinstimmung erzielt.

Luftverschmutzung ist ein zentrales Thema der Umweltmedizin. Dabei beeinflusst partikuläre Luftverschmutzung entscheidend die Luft, besonders auch in Leipzig. Die Problematik „Feinstaub“ steht aktuell im Fokus von Politik, Rechtssprechung, Presse und Wissenschaft. Zahlreiche Studien belegen die Zusammenhänge zwischen aerosolbelasteter Luft und vielgestaltigen Gesundheitsgefährdungen. Insbesondere das respiratorische System kann durch luftgetragene Partikel gravierende Schädigung erfahren. Lange Zeit wurden ausschließlich die Massekonzentrationen der Partikel untersucht. Jüngere Forschungsbemühungen auf diesem Gebiet konzentrieren sich jedoch verstärkt auf chemische und physikalische Eigenschaften der Partikel. Die vorliegende Arbeit untersucht die Einflüsse von Partikelkonzentrationen auf die respiratorische Gesundheit im prähospitalen Bereich der notfallmedizinischen Versorgung in Leipzig. Es galt hierbei vorrangig die Einflüsse von Anzahl, Oberfläche und Volumen der luftgetragenen Partikel auf die respiratorischen Notfallrisiken zu untersuchen.

Particle-laden flows occur in a variety of natural and industrial situations. As particulate suspensions flow through a medium, particles are often retained at constrictions such as pore throats, outlets or orifices. This occurs not only with oversized particles, but also with particles smaller than the constriction. For instance, jams are caused by the formation of particle bridges/arches when several particles attempt to flow through a constriction simultaneously. In many instances the success of an operation depends on our ability to either ensure or stop the flow of particles in the flow stream. Managing the flow of sand into wellbores during hydrocarbon production from poorly consolidated sandstone reservoirs, also referred to as sand control, is one such application in the oil and gas industry. This dissertation presents a multi-pronged effort at modeling the flow of granular suspensions of different concentrations, and through pore openings of different shapes, with two main objectives: (1) predicting the mass and size-distribution of the particles that are produced before jamming, and (2) investigating the underlying factors that influence the onset and stability of particle arches. Since, the dominant interactions and retention mechanisms are concentration dependent, we divided particulate suspensions into three groups based on the volumetric particle concentration ([phi]). High-concentration suspension flows ([phi]>~50%) are dominated by particle-particle interactions. We modeled polydisperse sand packs flowing through screens with rectangular and woven-square openings using 3D discrete element method (DEM). Simulations were validated against experimental data for a wide range of screen opening and sand size distributions. From the experiments and DEM simulations, a new scaling relation is identified, in which the number of different sized particles produced before retention follows a power-law correlation with the particle-to-outlet size ratio. This correlation is explained with a simple probabilistic model of bridging in polydisperse systems and a particle-size dependent jamming probability calculated from experimental data. A new method is presented to estimate the mass and size distribution of the produced solids through screens. The method uses the entire particle size distribution (PSD) of the formation sand, is validated with experimental data and numerical simulations, and provides more quantitative and accurate predictions of screen performance compared to past methods. It is also found that the stability of particle arches is compromised when adjacent outlets are less than three particle diameters away from each other. Low-concentration suspension flows ([phi]<~1%) are dominated by particle-fluid interactions. They were modeled using analytical and stochastic methods to predict sand production through screens with slot and woven-square openings. Analytical expressions were derived for screens with a constant outlet size or with a known outlet size distribution. Monte Carlo simulations showed excellent agreement with the analytical solutions. Based on experiments, we have demonstrated that the models presented here are predictive, provided that an accurate representation of the formation sand PSD and the screen pore size distribution are available. In the intermediate-concentration regime (~1%<[phi]<~50%), the particle trajectories and the flow field are both influenced by each other. The onset of particle bridging due to hydrodynamic forces was studied for monodisperse systems, in a rectangular channel with a single constriction, using coupled computational fluid dynamics (CFD) and DEM simulations. It is shown that the probability of jamming increases with [phi], and there is a critical particle concentration ([phi, superscript asterisk]) for spontaneous bridging. The outlet-to-particle size ratio is the most critical parameter affecting [phi, superscript asterisk]. The effect of inlet-to-particle size ratio, fluid velocity, particle stiffness, particle-to-fluid density ratio, and the effect of convergence in flow geometry were also studied quantitatively. Finally, the application of micro-tomography images in constructing accurate 3D representations and calculating the pore size distribution of complex filter media is demonstrated. A simulation tool is presented that allows one to evaluate the performance of different screens without running expensive and sometimes inconclusive experiments, and enhances our understanding of screen performance. This helps to improve sand screen selection to meet performance criteria under a wide variety of conditions. / text

Dissolved organic matter (DOM) is crucial to carbon and nutrient biogeochemical cycling in the marine environment because it helps fuel heterotrophic microbial activity by providing substrates for degradation and remineralization. This study shows that substantial production of DOM in Texas estuaries can result from the solar radiation-enhanced dissolution (photodissolution) of particulate organic matter (POM). Experimental results showed that 0.4-6.6 mg C L⁻¹gsed⁻¹ of dissolved organic carbon (DOC) and 0.03-0.93 mg N L⁻¹gsed⁻¹ of total dissolved nitrogen (TDN) can be produced from irradiated sediment suspensions within 24 hours, and further that photodissolution may augment DOC and TDN loads in Texas estuarine waters by as much as 3-85% and 4-75%, respectively. Photodissolution can also enhance the optical thickness of the water column via the release of chromophoric dissolved organic matter (CDOM), which may subsequently further enhance photochemical processes in surrounding waters. Photoproduced CDOM appears to be of relatively high molecular weight and dominantly exhibits humic-like fluorescence, suggesting that photodissolution primarily occurs for humic moieties. Photodissolution was also observed for sterilized sediment suspensions, indicating that photochemical degradation of POM is the primary pathway of DOM production during photodissolution, as opposed to microbial mediated degradation or stimulation of benthic primary production by benthic phytoplankton or algae. Environmental and mechanistic factors controlling the extent of photodissolution in Texas estuaries may include sediment desiccation, water organic content, and sediment characteristics (organic content and lability of POM). Desiccated-rewetted sediments suspended in artificial seawater under solar irradiation produced ~40% more DOC and TDN than wet sediments, indicating the sediment dry-wet cycle may alter the 3-D structure of sediment grain matrices and thus might be a major controlling factor of photodissolution in salt marsh systems. The organic content of water used in sediment suspensions did not significantly influence DOC or TDN photoproduction by itself, but the combined influence of water organic content and sediment dry-rewet event played a substantial role in controlling the extent of photodissolution. In contrast to the results in artificial seawater, wet sediments produced slightly more DOC ([Delta]DOC=0.10 mg C gsed⁻¹) and substantially more TDN ([Delta]TDN=0.14 mg N gsed⁻¹) than dry-rewetted sediments in organic-rich Nueces Marsh water during 24 hours of photoincubation. Photodissolution dominantly produced humic-like DOM even though biologically labile organic matter was available in sediments, indicating that photochemical reactions preferentially occur with humic-like rather than protein-like organic matter. DOC and TDN production during photodissolution was strongly proportional to the amount of POC in sediment suspensions. On average, 69.2 ± 11.0 mg C of DOC and 9 ± 3.1 mg N of TDN was produced from 1 g of organic carbon in sediment suspensions after 24 hours of photodissolution. / text

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 2x1013 and 4x1013 /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.

A field campaign was conducted in Greece during the summer of 2012 (June 8 – July 26) to investigate ambient particulate matter (PM) levels, chemical composition and contribution of regional and local sources. Simultaneous collection of PM1, PM2.5 and PM10 samples took place in seven different sampling sites in Greece. The sampling sites included: i) one urban and one suburban station in Patras, ii) one suburban in Thessaloniki, iii) one suburban and one background station in Athens, iv) one rural background station at the Navarino Environmental Observatory (NEO) in southwest Peloponnese and v) one remote background site at Finokalia in the northeast part of Crete. These different sites were chosen in order to estimate the contributions of the local emissions sources and long range transport. A suite of continuous/online instruments was deployed in selected sites including an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF AMS), an Aerosol Chemical Speciation Monitor (ACSM), a Proton-Transfer Reaction Mass Spectrometer (PTR-MS), a PM2.5/PM10 Tapered Element Oscillating Microbalance (TEOM), filter samplers (PM1, PM2.5 and PM10), nephelometers, aethalometers and gas-phase monitors. The campaign PM2.5 average ranged from 14 to 20 μg m-3 for the different sites. The fine PM mass concentration and chemical measurements were quite similar in all sites suggesting significant contributions of transported regional pollution and smaller contributions of local sources. Sulfate and organics were major PM2.5 components in all sites. Also nitrate, dust and sea-salt for the coastal areas were also important components of the PM10 fraction. The sulfate levels were similar in all sites, while the concentration of the organics and dust were more variable. Most of the organic aerosol was highly oxygenated. Back trajectory analysis, based on FLEXPART, identified five source regions (Greece, Athens, Turkey, Balkans, marine) each of which influenced the PM1 aerosol composition. / --