There is a need for a robust and accurate technique to measure ammonia (NH3) emissions from animal feeding operations (AFOs) to obtain emission inventories and to develop abatement strategies. Seasonal studies were conducted to measure NH3 emissions from open-lot and free-stall dairies in central Texas since summer of 2003. Ammonia emission flux (EFl) was measured using an isolation flux chambers (FC) protocol from ground level area sources (GLAS) and converted to emission factor (EF) to potentially develop source specific NH3 emission control strategies. The GLAS including open-lots, free-stall barns, separated solids, primary and secondary lagoons and milking parlor were sampled to estimate NH3 emissions. In the first study, assessment of summer and winter data from the open-lot dairy indicated that overall NH3 EFs were 11.6 ±7.1 kg NH3 year-1 head-1 for the summer and 6.2 ±3.7 kg NH3 year-1 head-1 for the winter season. The estimated annual NH3 EF was 9.4 ±5.7 kg NH3 year-1 head-1 for this open-lot dairy. The estimated NH3 emission factor for winter was nearly 47% lower than summer EF. Open-lot corrals (~63%) in summer and (~95%) in winter were the highest contributors to NH3 emissions for the open-lot dairy. In the second study, the EFs for the free-stall dairy were determined to be 11.1 ±4.9 kg NH3 year-1 head-1 for summer season and 4.7± 4.9 kg NH3 year-1 head-1 for winter season. The estimated annual NH3 EF was 8.4 ±4.9 kg NH3 year-1 head-1 for this free-stall dairy. In winter, composted manure and free-stalls contributed nearly 73% to the total NH3 emissions for the dairy. However in summer, approximately 65% of overall NH3 emissions were contributed by two lagoons at the dairy. The overall differences between winter and summer NH3 emissions from the dairies were due to ambient temperature variations and loading rates of manure on GLAS. There was spatial variation of NH3 emissions from the open-lot earthen corrals due to variable animal density within different divisions of the open-lot. This spatial variability was attributed to dispirit manure loading within these areas.

A protocol was developed to measure ammonia emission concentrations from dairies using an isolation flux chamber. A hybrid dairy in Comanche county, Texas, was measured for one week each during August 2002 and January 2003. Sixty total ammonia samples were taken from the free stall barn, open lot, mixing tank, separated solids, compost, and two lagoons using the developed protocol. The ammonia concentration measurements were made using a chemiluminescence analyzer located inside a mobile laboratory. From the emission concentrations recorded, it was estimated that 9.68 metric tons of ammonia were produced from this dairy per year. An emission factor of 13.34 ± 28.80 kilograms per day per thousand head of cattle (kg/day/1000 head) was estimated for this dairy (±95% confidence intervals) during summer conditions. For winter conditions the emission factor was 12.05 ± 12.89 kg/day/1000 head. The 11% difference of the emission factors from summer to winter conditions was predominantly from the change in ambient and control volume temperatures (a mean difference of approximately 25 degrees Celsius), differences in source temperatures, and seasonal variability in husbandry. The adsorption of ammonia onto different polymer tubing used in pollutant stream conveyance was researched for possible systematic losses. Teflon and low density polyethylene (LDPE) were tested for ammonia losses with treatments of: temperature, length, and inlet concentration. Inlet concentration and temperature were significant factors used to describe ammonia adsorption for Teflon, whereas LDPE was also affected by tubing length. These factors were used to create a model to correct the summer dairy measurements for ammonia losses, resulting in an emission factor increase of 8.3% over the original value obtained from the flux chamber. A nitrogen mass balance was performed to estimate the amount of nitrogen available for ammonia formation as excreted - 177.5 kilograms per year per animal (wet basis). The amount of ammonia excreted per year was also estimated to be 26.63 kilograms per year. The measured ammonia emitted from the dairy was five times less than the ammonia excreted and thirty-six times less than the total nitrogen excreted.

A protocol was developed to measure ammonia emission concentrations from dairies using an isolation flux chamber. A hybrid dairy in Comanche county, Texas, was measured for one week each during August 2002 and January 2003. Sixty total ammonia samples were taken from the free stall barn, open lot, mixing tank, separated solids, compost, and two lagoons using the developed protocol. The ammonia concentration measurements were made using a chemiluminescence analyzer located inside a mobile laboratory. From the emission concentrations recorded, it was estimated that 9.68 metric tons of ammonia were produced from this dairy per year. An emission factor of 13.34 ± 28.80 kilograms per day per thousand head of cattle (kg/day/1000 head) was estimated for this dairy (±95% confidence intervals) during summer conditions. For winter conditions the emission factor was 12.05 ± 12.89 kg/day/1000 head. The 11% difference of the emission factors from summer to winter conditions was predominantly from the change in ambient and control volume temperatures (a mean difference of approximately 25 degrees Celsius), differences in source temperatures, and seasonal variability in husbandry. The adsorption of ammonia onto different polymer tubing used in pollutant stream conveyance was researched for possible systematic losses. Teflon and low density polyethylene (LDPE) were tested for ammonia losses with treatments of: temperature, length, and inlet concentration. Inlet concentration and temperature were significant factors used to describe ammonia adsorption for Teflon, whereas LDPE was also affected by tubing length. These factors were used to create a model to correct the summer dairy measurements for ammonia losses, resulting in an emission factor increase of 8.3% over the original value obtained from the flux chamber. A nitrogen mass balance was performed to estimate the amount of nitrogen available for ammonia formation as excreted - 177.5 kilograms per year per animal (wet basis). The amount of ammonia excreted per year was also estimated to be 26.63 kilograms per year. The measured ammonia emitted from the dairy was five times less than the ammonia excreted and thirty-six times less than the total nitrogen excreted.

In 1990, creosote contamination was discovered at a railroad tie yard in Oneida, Tennessee. A phytoremediation system that included over 1,200 hybrid poplar trees was installed between 1997 and 1998 for hydraulic control of the groundwater and enhancement of the natural biodegradation processes in the subsurface. Since then, Virginia Polytechnic Institute and State University has monitored eight polycyclic aromatic hydrocarbons (PAHs) in the soil and groundwater. They have found that concentrations of smaller and more volatile PAHs have decreased over the years as the DNAPL contamination has become more enriched with the larger PAHs. This thesis focuses on the movement of naphthalene through the subsurface because it comprises the majority of the creosote and evidence for its remediation exists. Of the many mechanisms within the phytoremediation system that serve to remediate contaminated groundwater and soil, the most important are rhizosphere bioremediation and plant uptake. However, another mechanism, direct volatilization through the soil, was thought to have significant remediation capabilities at this site. Because naphthalene is a highly volatile PAH, it was hypothesized that naphthalene is volatilizing directly through the soil to the atmosphere and that the rate of volatilization may be enhanced by the presence of the phytoremediation system. The goals of this research are to measure the amount of naphthalene that volatilizes from the subsurface and determine the factors that significantly influence this direct volatilization. A flux chamber was designed and constructed to measure naphthalene fluxes from the soil. Factors that influence direct volatilization include the groundwater level, soil moisture, precipitation, pressure changes, temperature and humidity, the most important of which we found to be the groundwater level through its influence on naphthalene concentrations in the groundwater. We found that the presence of the trees significantly affects groundwater levels. As trees transpire and lower the groundwater table, concentrations in the uppermost portion of the groundwater increase, and under dry conditions, naphthalene fluxes from the soil are maximized. To complement the field measurements of direct volatilization, we also investigated rates of volatilization and biodegradation in the laboratory. Column experiments were conducted to determine the importance of direct volatilization on biodegradation in the vadose zone. We hypothesize that the combined mechanisms of contaminant transfer to the vadose zone, followed by rapid biodegradation, speeds up remediation in contrast to biodegradation that occurs only in the saturated zone under high groundwater conditions. Several columns using contaminated and uncontaminated soil from the site were constructed with a naphthalene source. Vertical naphthalene vapor concentration profiles were measured, and first-order biodegradation rates were determined. We found that biodegradation rates in the bacterially active columns were small initially, but that the biodegradation rates of the contaminated soil dramatically increased at day 60, while the biodegradation rates of the uncontaminated soil did not begin to increase until day 150. By the end of the experiment, both soil types had approximately the same biodegradation rate, signifying that soil that had previously been exposed to naphthalene degrades naphthalene more efficiently in the early stages than soil that has not been exposed, but that over time the non-exposed soil degrades naphthalene as efficiently as the pre-exposed soil. We determined that the combined mechanisms of diffusion and biodegradation in the unsaturated zone have significant remediation capabilities. Because long-term exposure risks are associated with inhaling indoor contaminant vapors, the Johnson and Ettinger vapor intrusion model was applied to the creosote-contaminated site, as outlined in Appendix C. This model takes into account soil, chemical, and building foundation characteristics to determine a dimensionless attenuation ratio, which is the ratio of contaminant vapor concentration in an enclosed space (i.e. basement) to the vapor concentration directly above the source. For a conservative case, the Johnson and Ettinger model without biodegradation was used. We found that if the land were developed, naphthalene vapor intrusion would not pose any health risks based on regulatory standards and levels at which health effects have been recorded. / Master of Science

A preliminary study shows that Submarine Groundwater Discharge (SGD) exists around Taiwan even though groundwater overdrawing is serious. Only five of the 20 sites studied did not record any SGD signal. Two nearly fresh SGD samples were obtained, providing strong and direct evidence for the existence of SGD in Taiwan. SGD is the submarine seepage of all fluids from coastal sediments into the overlying coastal areas. It has been well documented that SGD may contribute much nutrients to the coasts (Burnett et al.,2001, 2003; Church, 1996; Taniguchi et al., 2002; Zhang and Satake, 2002). Because of its difficulty in measurement, there are few reports on the characteristics of groundwater seepage, such as the flow rate and the water chemistry. In Taiwan, the only report was published in the Japanese journal Geochemistry (Chen et al. , 2005 ). In this study, samples were collected monthly from May, 2004 to June, 2006 at Xiziwan and Caishan in Kaohsiung. A flux chamber was also used in the observation of the SGD seepage rates. Further, samples were collected from 20 different places around Taiwan. The SGD collecting device, the SGD-Flux chamber and the Lee type seepage meter (Zhang et al., 2005) were used in this study, the latter being the first time used to explore the SGD flux in Taiwan. Salinity, dissolved oxygen saturation (%), nutrients (NO3, NO2, PO4, SiO2, NH3), total alkalinity, pH and major ions were analyzed. We averaged all seepage rate data at Xiziwan and Caishan to estimated the SGD seepage rate at about 1.32¡Ó1.57 L/m2/hr. The average concentrations of inorganic nitrogen (NO3+NO2+NH3), PO4 and SiO2 are, respectively, 48.6¡Ó86.3 (n=85), 0.78¡Ó1.26 (n=110) and 55.1¡Ó39.8

Ammonia emissions from animal feeding operations (AFOs) have recently come under increased scrutiny. The US Environmental Protection Agency (EPA) has come under increased pressure from special interest groups to regulate ammonia. Regulation of ammonia is very difficult because every facility has different manure management practices. Different management practices lead to different emissions for every facility. Researchers have been tasked by industry to find best management practices to reduce emissions. The task cannot be completed without equipment that can efficiently and accurately compare emissions. To complete this task, a measurement system was developed and performance tested to measure ammonia. Performance tests included uncertainty analysis, system response, and adsorption kinetics. A measurement system was designed for measurement of gaseous emissions from ground level area sources (GLAS) in order to sample multiple receptors with a single sensor. This multiplexer may be used in both local and remote measurement systems to increase the sampling rate of gaseous emissions. The increased data collection capacity with the multiplexer allows for nearly three times as many samples to be taken in the same amount of time while using the same protocol for sampling. System response analysis was performed on an ammonia analyzer, a hydrogen sulfide analyzer, and tubing used with flux chamber measurement. System responses were measured and evaluated using transfer functions. The system responses for the analyzers were found to be first order with delay in auto mode. The tubing response was found to be a first order response with delay. Uncertainty analysis was performed on an ammonia sampling and analyzing system. The system included an analyzer, mass flow controllers, calibration gases, and analog outputs. The standard uncertainty was found to be 443 ppb when measuring a 16 ppm ammonia stream with a 20 ppm span. A laboratory study dealing with the adsorption kinetics of ammonia on a flux chamber was performed to determine if adsorption onto the chamber walls was significant. The study found that the adsorption would not significantly change the concentration of the output flow 30 minutes after a clean chamber was exposed to ammonia concentrations for concentrations above 2.5 ppm.

Mercury (Hg) is a potent human toxin and a persistent global pollutant with unique properties and environmental behaviours which make it difficult to model and understand. While anthropogenic mercury sources are well understood along with the impacts on ecosystems and human populations, the processes and transformations which govern environmental cycling lack the same level of understanding. Concentrations in Arctic environments are a specific concern, along with cycling behaviours in regions spanning from temperate to Arctic climates. The objective of this experiment was the investigation and characterization of the mechanisms which promote elemental mercury (Hg^0) flux from soils in these environments during simulated seasonal cycling. A laboratory scale experiment was conducted which used a Dynamic Flux Chamber (DFC) to monitor Hg^0 flux from a naturally Hg enriched soil during temperature cycling relevant to cold environments. The results, which were split into freeze-thaw (FT) and sub-zero (SZ) cycles, showed that Hg^0 flux from frozen soils remains active during temperature cycling. During FT cycles, Hg^0 flux is controlled by soil temperature and energy entering the system, with a linear increase in flux for increases in energy. This response is produced from the entire soil column. During SZ cycles, Hg^0 flux is produced only in the thin soil surface layer and is controlled by the air temperature at the soil-air interface. A decrease in the DFC air temperature was observed to produce an increase in flux, with an inverse relationship controlled by a separate mechanism than the FT cycle response. Recommendations for modifications to the experimental set-up and methodology have been made to improve the accuracy of the results and confirm the behaviours characterized during this study. / Natural Sciences and Engineering Research Council of Canada (NSERC)

A flux chamber is an effective and recognized means of sampling off gassing surfaces, such as landfills and settling ponds. Because there has been little discussion on the survey patterns used for deploying flux chambers. This thesis looks into developing a scalable survey pattern as part of a flux chamber test methodology that can accurately give a representative sample of the emission components and the emission rate of the entire area of interest. The test methodology evolved out of literature review and experiences of two case studies which are discussed within this thesis.

A major uncertainty in soil carbon studies is how inputs of fresh plant-derived carbon affect the turnover of existing soil organic matter (SOM) by so-called priming effects. Priming may occur directly as a result of nutrient mining by existing microbial communities, or indirectly via microbial population adjustments. Soil type and conditions may also influence the intensity and direction of priming effects. However the mechanisms are poorly understood. The objectives of this study were (1) to investigate how additions of labile C4 substrate affected SOM turnover in two contrasting unplanted C3 soils (clayey fertile from Temple Balsall, Warwickshire (TB) and sandy acid from Shuttleworth, Bedfordshire (SH) using13 C isotope shifts; (2) to investigate the influence of rhizodeposition from plant roots on SOM turnover in the same two soils planted with a C4 grass; (3) to assess an automated field system for measuring soil temperature, moisture and photosynthesis sensitivities of SOM turnover in the same two soils over diurnal to seasonal time scales. I used a combination of laboratory incubation, glasshouse and field experiments. In the soil incubation experiment, I made daily applications of either a maize root extract or sucrose to soil microcosms at rates simulating grassland rhizodeposition, and followed soil respiration (Rs) and its δ13 C over 19 days. I inferred the extent of priming from the δ13 C of Rs and the δ13 C of substrate and soil end-members. There were positive priming effects in both soils in response to the two substrates. In the SH soil there were no differences in priming effects between the substrates. However in the TB soil, sucrose produced greater priming effects than maize root extract, and priming effects with sucrose increased over time whereas with maize root extract declined after the first week. I explain these effects in terms of the greater fertility of the TB soil and resulting greater microbial nitrogen mineralization induced by priming. Because the maize root extract contained some nitrogen, over time microbial nitrogen requirements were satisfied without priming whereas with sucrose the nitrogen demand increased over time. In the glasshouse experiment, I planted C4 Kikuyu grass (Pennisetum clandestinum) in pots with the same two soils. The extent of rhizodeposition by the plants was altered by intermittently clipping the grass in half the pots (there were also unplanted controls) and priming effects were inferred from the δ13 C of Rs and the δ13 C of plant and soil end-members. Unclipped plants in both soils generated positive priming effects, while clipping reduced priming in TB soil and produced negligible PEs in SH soil. Microbial nutrient mining of SOM again explained the observed PEs in this experiment. Photosynthesis was a major driver of priming effects in the planted systems. In the third experiment, I found that the tested automated chamber system provided reliable measurements of Rs and net ecosystem exchange (NEE), and it was possible to draw relations for the dependency of Rs and NEE on key environmental drivers. Collectively, the results contribute to a better understanding of the mechanisms of priming effects and highlight possibilities for further research. The methods developed here will allow high temporal and spatial resolution measurements of Rs and NEE under field conditions, using stable isotope methods to separate fluxes into plant- and soil-derived components. Keywords: Soil respiration, soil moisture, soil temperature, Isotope ratio, maize root, flux chamber, climate change, organic matter, rhizodeposition.

The Stable high rate ammonia removal over nitrite (SHARON) at Nykvarnsverket in Linköping is a relatively new kind of biological treatment. Fluxes of nitrous oxide (N2O) has not been fully mapped at Nykvarnsverket and additional efforts are needed for increased knowledge about possible emissions. The primary goals of the study were to measure and compare fluxes of N2O in the SHARON and to do a general greenhouse gas (GHG) flux comparison to those of the Biological treatment, the Chemical treatment and the Second denitrification at Nykvarnsverket. Secondary goals were to evaluate the use of two gas sensors, a SiC-FET sensor for N2O emissions, a CO2 Engine ELG sensor for carbon dioxide (CO2) emissions and their applicability in a WWTP environment. The measurements of GHG fluxes were performed by measuring the temporal change of GHG concentrations in the headspace of floating flux chambers placed in treatment tanks. The two gas sensors were tested either via tests in lab or via field measurements. The flux chamber method made it possible to estimate the fluxes at three out of four targeted tanks. The total daily GHG flux estimations (mmol m-2 d-1 ) in the SHARON were 6900 CO2, 320 methane (CH4) and 35 N2O. The estimations (mmol m-2 d-1) in the Biological treatment were 22 000 CO2, 120 CH4 and 23 N2O for 75% of the time. The estimations (mmol m-2 d-1) in the Chemical treatment were 110 CO2, 0.073 CH4 and 0.60 N2O. The largest N2O emissions were found to occur during nitrification processes in the SHARON. The fluxes in the SHARON were also the largest compared to those in the Biological treatment and the Chemical treatment, except for the CO2 flux that was larger in the Biological treatment. The CO2 sensor could be used during measurements over shorter time periods were CO2 levels did not exceed 10 000 ppm. Further tests on the SiC-FET sensor are needed to evaluate the sensor for measurements of N2O.