<p> This study deals with the use of mass balance and hydrodynamic/pollutant transport models for wetland restoration. The models were applied to Cootes Paradise marsh, located at the western end of Hamilton Harbour, Lake Ontario. Regulated water levels, excess nutrients and high suspended solids have contributed to declining vegetation and a subsequent change in wildlife in this wetland ecosystem. The Royal Botanical Gardens (RBG), which manages Cootes Paradise, has developed goals for the restoration of this wetland which focus primarily on improving water quality. </p> <p> A mass balance approach was applied to Cootes Paradise in order to gather more information on the inputs of phosphorus and suspended solids to the ecosystem. Although data were not complete for many aspects of the model, the mass balance calculations provided an acceptable agreement with field values. The mass balance models also revealed that more than 50% of the inputs of phosphorus and suspended solids were being contributed by the internal sediments. </p> <p> A two-dimensional depth averaged hydrodynamic/pollutant transport model provided an explanation for the movement of substances through the marsh as a result of wind and inflow generated currents. The resulting pollutant distribution patterns could be explained by environmental conditions in the marsh ecosystem. The computer model predicted phosphorus concentrations reasonably well, both for an overall average of the entire marsh and for individual sites. The model also simulated suspended solids and accounted for contributions of particulate matter due to carp and due to wind resuspension of the bottom sediments. Both overall averages and sample site comparisons for suspended solids were within one standard deviation of field values. According to data generated by the computer model for suspended solids, carp and wind are contributing to the concentrations in Cootes Paradise on an almost equal level; both contribute approximately one third to the overall concentration for suspended solids based on the available data. Further information is needed, however, to improve on the data set for Cootes Paradise in order to better validate the results produced by the mass balance and computer models. </p> / Thesis / Master of Engineering (ME)

Glaciers are known as climate indicators because of their sensitivity towards climatic perturbations and fluctuations. A majority of the world’s glaciers are currently melting as a response to climatic perturbations. Glaciers in Norway display the same pattern, and the loss of mass have accelerated during the 1990s to this day. The glaciers of interest in this paper is situated in a west to east transect with the maritime Ålfotbreen in the west, to the continental Gråsubreen in the east, with the intermediate Storbreen in between. Differences in the local climate have a significant impact on the future state of glaciers. This paper aims to compare the mass balance, mass turnover and mass balance sensitivity of the three glaciers of interest, between the years 1980 and 2018, to demonstrate the importance of the local climate and characteristics for glacial existence. Mass balance data series of each glaciers’ mass balance was analysed. In addition, development trends of the mean annual summer air temperature for respective glaciers’ region were also conducted. A literature review of relevant reports and publications will be presented and analysed to complement the result of this paper. The results of this paper indicate that the characteristics of respective glacier vary along the increasing continentality of the west to east transect, with the mass balance sensitivity decreasing from west to east. The mass turnover displayed varying patterns, between the years 1980 and 2018. ÅLF had the highest mass turnover for the period and GRÅ the smallest with STO in between. It can be concluded, based on the result of this paper, that the fate of glaciers depends on geographical location and local characteristics. The resemblance between Storbreen and Storglaciären, and the existence of Helagsglaciären who seem to survive against the odds, strengthens the importance of local characteristics.

The aim of this research was to demonstrate the relationship between variations in summertime surface mass balance of the McMurdo Ice Shelf and atmospheric processes. The approach encompassed a broad range of techniques. An existing energy balance mass balance model was adapted to deal with debris-covered ice surfaces and modified to produce distributed output. Point based surface energy and mass balance for two key surfaces of the ice shelf were linked to different synoptic types that were identified using a manual synoptic classification. The distributed model was initialised with distributed parameters derived from satellite remote sensing and forced with data from a regional climate model. Patterns of summertime surface mass balance produced by the distributed model were assessed against stake measurements and with respect to atmospheric processes. During the summers of 2003-2004 and 2004-2005 an automatic weather station (AWS) was operated on bare and debris-covered ice surfaces of the McMurdo Ice shelf, Antarctica. Surface mass balance was calculated using the energy balance model driven by the data from the AWS and additional data from permanent climate stations. Net mass balance for the measurement period was reproduced reasonably well when validated against directly measured turbulent fluxes, stake measurements, and continuously measured surface height at the AWS. For the bare ice surface net radiation provided the major energy input for ablation, whereas sensible heat flux was a second heat source. Ablation was by both melt (70%) and sublimation (30%). At the debris-covered ice site investigated, it is inferred that the debris cover is sufficient to insulate the underlying ice from ablation. Synoptic weather situations were analysed based on AVHRR composite images and surface pressure charts. Three distinct synoptic situations were found to occur during the summers, these were defined as Type A, low pressure system residing in the Ross Sea Embayment; Type B, anticyclonic conditions across region; and Type C, a trough of low pressure extending into the Ross Sea Embayment. A dependence of surface energy fluxes and mass balance on synoptic situation was identified for the bare ice surface. The distributed model was found to produce spatial patterns of mass balance which compared well with stake measurements. Mass balance patterns show that the McMurdo Ice Shelf was generally ablating in the west, and accumulating in the east during summer. Areas of enhanced ablation were found which were likely to be caused by the surface conditions and topographic effects on the wind field. The mean summertime surface mass balance across the entire ice shelf for the 2003-2004 and 2004-2005 summers were –2.5 mm w.e. and –6.7 mm w.e. respectively. The differences between the two summers are inferred to be a result of more frequent type A conditions occurring during the summer of 2004-2005.

According to climatic models there will be an increase in the amount of greenhouse gases which results in a warming of the earth where the change will be most prominent in the high latitudes. Glaciers mass balance is a good climate change indicator as the response is fast when climate is changing. Glacier mass balance, area of glaciers, elevation line altitude data for 13 glaciers in Scandinavia as well as North Atlantic oscillation (NAO), Arctic oscillation (AO) and sunspot data where gathered and a principle component analysis (PCA) where made. PCA is a multivariate statistical technique with the goal to extract important information and reduce the dimension of data. Three distinct groupings where found within the data set and was identified as extreme years of North Atlantic Oscillation and Arctic Oscillation and one glacier which had the largest area of the 13 glaciers. The PCA explained that all the variables in the data set is correlated with North Atlantic and Arctic Oscillation to about 40 % and we can conclude that there is a regional and local forcing within our data where the regional (NAO and AO) is of more importance for the variance and for the mass balance. / Enligt klimatmodeller kommer en ökning av växthusgaser i atmosfären leda till en ökning av temperaturen på jorden, den ökningen kommer främst att ske på höga latituder. Glaciärer är bra indikation på förändrat klimat på grund av deras korta responstid när klimatet ändrar sig. För tillfället finns det ca 1900 glaciärer utspridda i de Skandinaviska bergen. Eftersom Skandinavien är så avlångt är det en skillnad i meterologiska och klimatiska förhållanden, både i en nord-syd riktning men även i en öst-väst riktning med kontinentala glaciärer i öst och mer marina i väst. Klimat och glaciärdata för 13 olika glaciärer i Skandinavien, 5 från Sverige och 8 ifrån Norge har samlats in och en statistisk analys, principle component analysis (PCA) har gjorts för att se vad som påverkar massbalansen för glaciärerna. De klimat parametrar som har undersökts är Nordatlantsika oscillationen (NAO), Arktiska oscillationen (AO) och solfläckar tillsammans med massbalans, equilibrium line altitude (ELA) och area för glaciärerna. Tre grupperingar har hittats som kan kopplas till olika klimatvariabler och PCA visar extremår för NAO och AO samt en glaciär som har den största arean. PCA analysen visade att alla variabler korrelerade till NAO och AO med omkring 40 % och vi kan dra slutsatsen att det finns en drivande regional och lokal kraft inom vårat dataset där NAO och AO är viktigast för massbalansen.

We have developed a regional mass balance model for the St. Lawrence River near Cornwall, Ontario that describes the fate and transport of mercury in three forms, elemental mercury (Hg0), divalent mercury (Hg2+), and methyl mercury (MeHg), in a five compartment environment (air, water, sediments, periphyton, and benthos). Our first objective was to construct a steady-state mass balance model to determine the dominant sources and sinks of mercury in this environment. Our second objective was to construct a dynamic mass balance model to predict and hindcast mercury concentrations in this environment. We compiled mercury concentrations, fluxes, and transformation rates from previous studies completed in this section of the river to develop the model in STELLA®. The inflow of mercury was the major source to this system, accounting for 0.42 mol month-1, or 95.5% of all mercury inputs, whereas outflow was 0.28 mol month-1, or 63.6% of all losses, and sediment deposition was 0.12 mol month-1, or 27.3% of all losses. The dynamic mass balance model provides estimated results that are consistent with measured data and predicts historical local industrial emissions to be approximately 400 kg year-1. Uncertainty estimates were greatest for advective fluxes in surface water, porewater, periphyton, and benthic invertebrates. This model is useful for predicting and hindcasting mercury concentrations in other aquatic environments because it contains the three main environmental compartments, all forms of mercury, and compartments (e.g. periphyton) not included in previous mercury multi-media models.

ABSTRACT It is important to improve ambient air quality by reducing the emission from mobile sources. In order to investigate the characteristics of mobile sources, the statistic of traffic flow and the measurement of suspended particles were conducted in the Gonguan air quality monitoring station of Miaoli County in this investigation. Through chemical mass balance (CMB) receptor model and backward trajectory model, the location and contribution of emission sources were further identified. Accordingly, the improvement strategies for mobile sources were further proposed to improve local ambient air quality. In order to know the traffic flow variability of motor vehicles, passenger cars, motorcycle, heavy-duty diesel trucks, and buses were recorded every 15 minutes by a video camera for both weekend and weekdays. In the meantime, TSP and PM10 were simultaneously collected with high-volume samplers. The metallic content and water-soluble ionic species of particulate matter were analyzed with an inductively coupled plasma-atomic emission spectrophotometer (ICP- AES) and an ionic chromatography (IC). Chemical composition of suspended particles was then be used for source apportionment with the CMB model. Finally, the improvement strategies for mobile source management were further proposed through the correlation of traffic flow and vehicle emission rate. The results showed that the PM10/TSP ratios of suspended particles collected at the rooftop of a four-floor building was higher than those sampled at the air quality monitoring station for all quarters except the third quarter. PM>10 is the main factor for the concentration difference of suspended particles sampled on the rooftop of the building as well as at the monitoring station. Results from traffic flow records showed that passenger cars were the major source contributing greatly to the traffic flow, while no significant variation of buses was observed in the traffic flow. The linear regression of PM>10 concentration and vehicles for different wind directions (i.e. northwest, southwest and northeast) was undertaken. The results showed that, when the winds were blown from the northwest and southwest, the determination coefficients (R2) of the regression were 0.1226 (passenger cars), 0.4821 (motorcycles), 0.1014 (heavy-duty trucks), 0.3113 (buses), and 0.1919 (total traffic flow) respectively. It was 0.6140 (passenger cars), 0.6227 (motorcycles), 0.7761 (heavy-duty trucks), 0.2111 (buses), and 0.6309 (total traffic flow), respectively, for the northeast winds. It concluded that the traffic flow has significant influence on the concentration of suspended particle at the downwind sites. Among the vehicles, heavy-duty trucks played a key role. Consequently, reducing truck flow has to be paid more attention for the improvement of ambient air quality. During the sampling period, Ca, Fe, and Al were the most abundant metals of suspended particles, while Mg, K, Zn, and Cu ranked the second. Besides, the metallic contents of suspended particles sampled at the rooftop were generally lower than those collected at the monitoring station. It suggested that street dusts had major contribution to Gonguan air quality monitoring station. Among the water-soluble ionic species, sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+) were major anions, converting mainly from SO2, NOx, and NH3. The results showed that the metallic contents in the second quarter were higher than that in the fourth quarter. However, an opposite trend was observed for anions. The Back Trajectory Model and CMB were applied to analyze the suspended particle. The results showed that the seasonal variation of air pollutants was also affected by the monsoon. Though air pollutants emitted from the nearby waste incinerators and industrial districts could be transported to the sampling site, resulting in unavoidable influence on suspended particles, tail gas and fugitive dusts emitted from vehicles were the most important sources contributed to the ambient air quality. The results indicated that motor vehicles were the major source of ambient suspended particles on the road sites. Therefore, the reduction of traffic emission should be the first step of the improvement strategies for ambient air quality. Especially, the emission of road dusts resulting from the drive-through of heavy-duty trucks should be paid more attention. This study proposed two strategies for improving ambient air quality: one for raising the road serving level and the other for reducing vehicles on road at the traffic crowd section. After the road serving level was improved, the TSP, NOx, CO and THC were respectively decreased about 41, 5,765, 316, and 62 g/day. The concentration of TSP, NOx, CO, and THC was respectively decreased about 95.66 £gg/m3, 38.59 ppb, 1.93 ppm, and 1.90 ppm. After carrying out special vehicle on the road control strategy, TSP, NOx, CO, and THC could be respectively decreased about 2,136, 19,291, 169,843, and 3181g/day. The concentrations of TSP, NOx, CO, and THC were respectively decreased about 96.03 £gg/m3, 52.25 ppb, 2.05ppm and 1.69ppm.. Thus, ambient air quality can be effectively improved if the heavy-duty trucks can be controlled during the rush hour. Furthermore, a substitute road for heavy-duty trucks is another option for the improvement of ambient air quality.

The high-volume air sampling (PS-1) and micro-orifice uniform deposit impactor (MOUDI) were used to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere for four seasons at Zuoying and Siaogang in Kaohsiung city, together with the size distributions. Also, the CMB (Chemical Mass Balance) receptor model was employed to determine the potential sources of PAHs. The results show that the highest concentrations of PAHs occurred in winter, being 143.9 ng/m3 and 182.9 ng/m3 at Zuoying and Siaogang, respectively; while the lowest concentrations of PAHs occurred in summer, being 81.4 ng/m3 and 95.2 ng/m3. The low-weight PAHs in the two sites were abundant in gaseous phase, being 55.89 - 95.89 % and 67.07 - 96.61 % at Zuoying and Siaogang, respectively. Meanwhile, the high-weight PAHs were almost present in particulate phase, being 55.24 - 83.50 % and 46.87 - 77.26 % at Zuoying and Siaogang, respectively. The sizes of 50th percentile of cumulative size distribution, d50 of Zuoying and Siaogang were 0.89 £gm and 0.35 £gm, respectively. Hence, most atmospheric PAHs existed in fine-particle ranges (¡Õ1.0£gm). The results of by CMB receptor modeling indicated that the major sources of pollution was exhaust emission (49 - 62 %) in Zuoying, and was burning source (49 - 64 %) in Siaogang.

In the Kebnekaise Massif, Northern Sweden, the west facing glacier, Rabots glaciär, is loosing volume at a significantly higher rate than east facing, Storglaciären. By analyzing data from automatic weather stations situated on the ablation area on the glaciers we investigated the effect of meteorological differences on ablation. There was a difference in micro-climate between Rabots glaciär and Storglaciären. Generally Storglaciären had slightly warmer and drier air, had less or a thinner cloud layer but more precipitation. On both glaciers a glacier wind is dominant but high wind velocities were common especially on Storglaciären indicating a larger influence from the synoptic system. There was a good correlation for temperature and vapor pressure between the glaciers that indicate that both glaciers are strongly affected by the synoptic system. The meteorological parameters have similar effect on the ablation on the glaciers. Temperature, vapor pressure and the turbulent heat fluxes are the only meteorological parameters that suggest a linear affect on ablation. Net shortwave radiation contribute with the greatest amount of energy for ablation but decreased in relative importance as the temperature increased. Shortwave radiation, sensible and latent heat contributed with a total 184Wm-2 on Rabots glaciär and 222Wm-2 on Storglaciären. Rabots glaciär seem to have a significantly greater relative importance of the turbulent heat fluxes than Storglaciären. Although the differences in micro-climate were not great, using the ablation for Storglaciären to estimate ablation on Rabots glaciär would over estimate the ablation with 0.5m w.e..

Carbon Dioxide (CO2) is a major fermentation product generated during the production of beer, the subsequent release of this gas within the fermentor results in agitation that is necessary for sustained industrial fermentation. CO2 is sometimes monitored allowing brewers to stoichiometrically relate CO2 released to other products. In this manner the rate of gas release from the fermentor may be used to assess, control and predict other aspects of fermentation. The dynamics of CO2 generation, transport and release are explored throughout this thesis over several studies. The tools used to examine CO2 production were scrutinized including a miniature assay using various modeling techniques. A miniature scale fermentation assay included in the methods of the American Society of Brewing Chemists was compared to industrial scale fermentations. It was found that discrepancies were possibly due (at least in part) to fermentor geometry. Following this study, a literature review of CO2 solubility in aqueous sugar, and ethanol solutions was conducted. This study exposed previously undescribed inaccuracies in literature, i.e., it was found that several gas solubility tables were empirical derived and are therefore unlikely to accurately reflect all styles of beer. The next study scrutinized the consumption of sugars during barley fermentation and found that these fermentations often exhibit asymmetric sigmoidal attenuation. A five parameter logistic model was introduced to model this sugar consumption more accurately than previously described techniques. Using methods refined during the aforementioned studies, a fermentation was conducted where a mass balance was used to track all major fermentation parameters (the consumption of individual sugars, and the production of ethanol, carbon dioxide, yeast biomass and glycerol). This allowed an assessment of Balling’s theorem as compared to modern theory. It was shown that while accurate in predicting original extract, Balling’s theorem incorrectly quantified other fermentation parameters. This has large ramifications for both industry and research as the estimation of fermentation parameters (such as ethanol and fermentation time) is now better understood. From these studies, the production of beer becomes less of a “black box” operation, and CO2 saturation, transport and release can be better explained. Of the many fermentation aspects monitored during these studies, most were predicted by theory, however, there were notable exceptions. For instance, it was found that both the inhibition of maltose consumption and yeast sugar consumption dynamics (which remained relatively constant throughout the fermentation at ~ 50 pg·h-1 for cells with an average mass of ~ 40 pg). were found to deviate from previously described reports. These, and other findings improve our understanding of brewing fermentations allowing for additional applications of theory and recommendations in industrial operations.

No description available.