Climate change impacts the hydrological cycle. The intensity of extreme precipitation events and droughts is expected to increase, creating stress on the water and wastewater infrastructure. The objective of this study is to assess the potential impacts of climate change on the existing water and wastewater treatment infrastructure in rural Eastern Ontario. In total, 13 municipal WTPs and 28 municipal wastewater treatment systems in the Eastern Ontario region were investigated. These facilities were characterized using existing data, questionnaires, and sites visits. On the basis of this information, potential impacts of climate change were identified. One conclusion of this analysis was the potential need to convert lagoon systems to mechanized WWTPs. Such a conversion would represent a significant financial burden for a small community. Therefore, a cost-estimation methodology was developed, based on the existing CAPDET software. Dry periods, heavy rain events, heavy spring runoff and increased temperatures are the critical climate change phenomena that are expected to have the greatest impact on the water infrastructure of the study area. It was found that WTPs on the Ottawa River and the St. Lawrence River are not likely to exhibit water shortages, but those using smaller surface water sources are more vulnerable to water scarcity. Furthermore, this vulnerability to water scarcity will be exacerbated by and increase in water demand resulting from higher temperatures and more severe droughts. Turbidity events typically occur during periods of heavy runoff, and it is expected that climate change will increase the intensity of heavy runoff events. Taste and odor problems due to algal growth during spring and summer are an existing concern for at least five facilities in the study area. It is expected that this phenomenon will increase as a consequence of increased temperatures, increased evaporation rates and longer dry periods during the spring, summer and fall. Inflow and infiltration into the sewer system during spring runoff and rain events are typical problems in the study area, resulting in high peak flows at wastewater treatment facilities. Currently, certain WWTPs in the study area use bypass as a method to cope with extreme peak flows. It is expected that climate change will increase the intensity of spring runoff, and the intensity and frequency of rain events. Consequently, it is likely that there will be an increase in the frequency of bypass events, and an increase in the volume of bypassed wastewater. In lagoon systems, intensified rain events will further swell the normal wastewater flow to several times the dry weather flow, likely causing incomplete treatment of the wastewater particularly at continuous discharge lagoons. During dry periods and warm weather, algal growth in lagoon systems will likely increase. The discharge of effluent containing high quantities of algae will degrade the receiving waters quality. An increased frequency and intensity of periods of low streamflows will reduce the dilution capacity of receiving waters, particularly in small streams. This increased vulnerability may eventually be reflected in more stringent discharge criteria. A reduction in streamflows could also lead to more extensive algal growth, resulting in more turbidity, more taste and odor problems and possibly algal toxins contaminations.

This thesis argues that what it terms fever narratives figure prominently in Charles Dickens’s fiction. Fever was regarded not as a symptom but as a generic disease that had sub-species, such as cholera, smallpox, typhus and typhoid, and that presented itself through devastating epidemics that frightened the public and drove the government to enact public health legislation. The core elements of the fever narrative – such as fever’s cause, pathology, treatment and prevention – were still not clearly understood. This inevitably heightened public anxiety and frustration, particularly given lengthy delays in the bureaucratic processes of Parliament and local governments in dealing with fever’s perennial threat. The politically favoured sanitarian narrative influenced Dickens significantly. Sanitarians believed that water and sewer projects in urban localities and improved sanitary practices would prevent most diseases. However, Dickens was influenced also by an alternative approach that this thesis calls the “medical narrative,” comprising a more holistic vision of public health, reliant on improved treatments, greater medical professionalism, and specialized hospitals, in addition to sanitary reform. Dickens’s 1840s novels reflected both approaches, but he emphasized the medical narrative in portrayals of the fevers of individual characters. In the 1850s, the predominant focus of fever narratives in Dickens’s journals and novels became fever of the social body – fever that figuratively infected English institutions or the country as a whole. Dickens’s fever narratives became progressively darker during these two decades and, with each novel onward from Dombey and Son (1846-48), his representations of fever apocalypses infecting both the rich and the poor became more strident, even to the extent of suggesting that the whole institutional and economic infrastructure of the country would suffer an irrevocable blow. The thesis argues that Dickens presented these minatory scenes of vengeance in response to what he perceived as the blindness of the middle class to the condition of the sick and poor of England. This reached a climax with “Revolutionary fever” in A Tale of Two Cities (1859). The thesis presents a final argument that Dickens’s stories of the early 1860s and Our Mutual Friend (1864-65) provided both a continuation of and a denouement for the two previous decades’ fever narratives, by offering a view of the dust of corpse upon corpse of those who were mowed down by fever, and of a river polluted by this dust. However, he foresees also the possibility of the fundamental regeneration of a more humane physical, social and institutional environment in England.

A nine month field and laboratory study was undertaken to measure, predict and model the variation of detected ammonia concentrations in landfill gas. An additional side study attempted to characterize organic trace contaminants found in landfill gas. The field project consisted of biweekly sampling of gas extraction wells from four Vancouver-area landfills for the analysis of NH₃-N in the gas and leachate. Methane and other common landfill gases were also analyzed. The wet chemical boric-acid sampling technique used in this study was estimated to have a ammonia gas recovery efficiency of 50 %. Other than a low recovery efficiency, problems encountered with this sampling technique was the high humidity and negative interferences inherent in the landfill gas. Laboratory analysis of the collected NH₃-N gas samples was by the automated phenate method, which could detect NH₃-N gas concentrations greater than 10 ppb. The NH₃-N concentrations in gas were found to exceed 600 ppb, but were more commonly in the 50 to 200 ppb range. In the statistical and graphical analysis, gas temperature and precipitation were found to correlate the most to the variation in ammonia gas concentration, while leachate ionic strength correlated strongest with most CH₄ % analysis. Prediction of both NH₃-N gas and CH₄ % by regression analysis was found to be suspect due to low R² values and non-normality of some data. Four different Henry's Law constants of ammonia gas were evaluated to help predict the concentration of NH₃-N in the gas phase. The combination of already measured NH₃-N leachate concentrations and Henry's Law constants yielded results that over and underpredicted measured NH₃-N gas data by 2000 fold or more. This leads the author to believe Henry's Law may not be applicable in a landfill environment due to non-equilibrium conditions coupling with various other reaction mechanisms. Comparison of landfill ammonia gas flux rates with total ammonia leachate flux rates in two of the four landfills yielded an insignificant gas flux rate of less than 0.03 % of the total leachate NH₃-N fluxes. The NH₃-N gas flux results were calculated from a spreadsheet emission model employing both convection and diffusion flow through the landfill cover. A comparison of the emission model results for the 20 ha Richmond landfill study area (3.862 kg/yr) compared favorably to the mass flux results determined from a simple gas generation mass balance model. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

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There is a requirement in the European Union to divert organic wastes from landfill because of the risk of methane emissions. One alternative is anaerobic digestion of organic wastes, such as food waste, to stabilise them whilst at the same time recovering the energy from them. One problem with this approach is that the high nitrogen content of food waste may lead to ammonia inhibition. A solution to this has been found for mesophilic digestion but had not been attempted in thermophilic digestion where ammonia toxicity is known to be more acute. The work was carried out in laboratory-scale semi-continuous digesters operated over long time periods to provide maximum opportunity for acclimatisation, and in duplicate to give an indication of reproducibility. A series of experimental runs were undertaken at thermophilic temperatures to assess the influence of trace element (TE) addition on the digestion process. These were carried out at organic loading rates (OLR) of 2, 3 and 4 g volatile solids (VS) l-1 day-1 against unsupplemented controls at OLR 2 g VS l-1 day-1. Although TE addition could offset the accumulation of VFA which occurred in response to an increasing concentration of total ammonical nitrogen (TAN), it could not prevent this. The high alkalinity resulting from ammonia, however, allowed the digesters to continue to produce methane until VFA had accumulated to high concentrations before eventual failure due to a rapid drop in pH. To determine the threshold inhibitory ammonia concentration in thermophilic digestion, one pair of digesters was run on synthetic low nitrogen food waste (low-N food waste) at an OLR 2 g VS l-1 day-1 and compared to a control pair running on domestic food waste at the same loading. All four digesters received TE supplementation. The digesters fed with low-N food waste showed consistently stable performance with pH ~7.4, IA/PA ratio ~0.4-0.5, SMP 0.39 l CH4 g-1 VS, 52-55% CH4, total VFA <500 mg l-1 and 88% VS destruction whereas the controls showed signs of failure after 112 days and irreversible VFA accumulation at a TAN concentration >3.5 g N l-1. One of the low N digesters was supplemented with urea slowly and one by a shock dose: both showed signs of VFA accumulation at TAN >2.5 gl-1 and, again, an irreversible trend in propionic acid build-up when TAN >4 g N l-1. Long term operation showed meta-stable conditions when the digesters were operated at TAN between 2.5 - 3.5g l-1 with oscillations in VFA (especially propionic acid) concentration. Mesophilic digestion at 37oC with TE addition showed very stable performance with pH ~8, IA/PA ≤ 0.3, SMP ~0.48 l CH4 g-1 VS, 55-60% CH4, total VFA < 300 mg l-1 and VS destruction ~75-78% with a final total ammonia nitrogen (TAN) concentration of 4.5 g N l-1. As the temperature in digesters was raised from 35 to 43 oC in 1oC steps a change in performance was noted when the temperature reached 40 oC. Above this temperature VFA concentrations rose above 4000 mg l-1 and biogas and methane production fluctuated. It is probable that the higher temperature increased the concentration of free ammonia nitrogen (FAN) to ~800 g N l-1 at the measured TAN concentration ~5.5-6.0 g N l-1 and this was sufficient be inhibitory even with TE dosing. Fluorescent in situ hybridisation (FISH) was used to identify the methanogenic populations in some of the trials over selected time periods. This showed changes in population structure both in relation to temperature (mesophilic or thermophilic) and also in response to increasing concentrations of TAN. At high TAN concentrations Methanomicrobiales was the dominant methanogenic group and under mesophilic conditions this proved to be extremely ammonia tolerant. A 14C radio-labelling assay confirmed the dominant pathway to methane formation was by the hydrogenotrophic route which reflected the known metabolic pathway of this methanogen. It was concluded that thermophilic digestion of source segregated domestic food waste would lead to instability and failure of the process unless measures were introduced to reduce the TAN concentration to < 3.5 g N l-1, and preferably to < 2.5 g N l-1. Keywords: Anaerobic digestion, food waste, biogas, VFA accumulation, ammonia inhibition, Fluorescent in situ Hybridisation (FISH).

Due to legislative pressures and the recent ban of trybutyl tin, alternative environmentally acceptable ship hull antifouling systems are required. This thesis uses a multidisciplinary approach to combine two disparate areas of research namely marine biology and surface engineering, to develop a novel natural product (NP) based antifouling system. The overall objective of this thesis is to transfer a natural marine biological defence mechanism into an engineered antifouling coating system. By combining natural product extraction and incorporation into a trial coating an extensive test programme was able to investigate the antifouling performance and address the issues of bringing this active area of research to the next technological readiness level. By using a stepwise approach to the development of the engineered solution, a suite of techniques were used to fully characterise a NP based system. The biological and surface engineering techniques adapted and developed are described here and their future use to evaluate a novel NP based antifoulant system is critically assessed. After an extensive literature review, an ethanol extract from the red seaweed Chondrus crispus was selected as the natural product source. NP specimens were harvested locally and also purchased as industrially processed dried algae. The industrially processed algae showed good antifoulant activity ( ≤ 25 μg mL-1) in laboratory bioassays and had a greater efficacy than the locally harvested samples highlighting its potential as an economically viable solution. The direct incorporation of the NP into a commercial control depletion polymer binder, allowed for the rapid development of characterisation techniques to evaluate the effects this had on the performance of the NP-binder matrix. The feasibility of a range of electrochemical techniques to measure corrosion potential, impedance, resistance and water uptake in the NP coating was critically assessed. A combination of open-circuit potential and electrochemical impedance spectroscopy provided a unique and rapid means to non-destructively measure the contribution of incorporated NPs to the degradation and water uptake of the binder film. Studies of biofilm growth were used to successfully measure community viability and structure using fluorescent staining and differential interference contrast microscopy. These techniques were found to be very informative on Southampton water marine biofilm community structure and were cross correlated by fourier transform infrared measurements. Resistance to biofouling was determined through field trials, an important testing platform for an antifouling system, and specifically trials which test the entire coated system including any primers and substrate preparation requirements. An initial NP antifouling performance greater than the booster biocide (Chlorothalonil) control was documented for one field trial over a period of the first 6 weeks. A key aspect was to determine the potential efficacy of NPs and their viability in a coating system. To achieve this, a range of standard and non-standard techniques were used to assess this novel combination of crude NP extract and commercial binder system. This work has shown that a limited antifoulant activity is achievable. By evaluating the effect of a NP on both the fouling community and a binder system this unique approach helps define key techniques to assess future NP antifoulants and identifies the optimisation required to increase their functionality.

Leachate clogging in the Leachate Collection System (LCS) due to chemical precipitations and biofilms produced by microbial activities is a common phenomenon in any Municipal Solid Waste (MSW) landfill. This study focuses on quantifying the factors that impact the micro-environment of leachate; and microbial activities that help the precipitates to form and attach to the LCS. It also evaluates the performance of operational changes that have been implemented or the potential alternatives and recommends the possible measures to reduce the severity of clogging. A field scale side-by-side pipe network, and several laboratory setups were used in this study. Calcite is identified to be the predominant phase present in the precipitates using XRD/XRF analysis which, concur with the previous studies. Microbial growth and activities enhance the precipitation of CaCO3 in LCS. Clogging in LCS pipes can be controlled if not eliminated by continuous monitoring along with frequent cleaning with physiochemical processes. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Objetivo: Comparar el nivel de conocimiento y aplicación de medidas de bioseguridad en estudiantes de pregrado y egresados de la carrera de odontología del periodo 2013-2018 de una universidad privada peruana. Materiales y Métodos: Estudio piloto descriptivo de tipo transversal observacional, siendo la población los estudiantes de pregrado y egresados de la carrera de odontología de una universidad privada peruana. Se tomó una muestra de 32 estudiantes de pregrado y 32 egresados de odontología de la misma institución, evaluándose el nivel de conocimiento mediante una encuesta autoaplicable y el nivel de aplicación de las medidas de bioseguridad por medio de una ficha observacional. El análisis univariado se obtuvo mediante frecuencias absolutas y relativas; para el análisis bivariado se utilizó la prueba de Chi-cuadrado y prueba exacta de Fisher. (p≤0.05) Resultados: El conocimiento sobre medidas de bioseguridad de los alumnos de pregrado y egresados es de nivel regular, con valores de 40.6% y 46.8% respectivamente, el 34.37% de alumnos de pregrado y el 25.56% del grupo de egresados obtuvieron un buen nivel de aplicación de las medidas de bioseguridad. Se encontró diferencias estadísticamente significativas entre el nivel de conocimiento de los alumnos de pregrado y egresados. (p= 0.001). Conclusión: Los grupos de pregrado y egresados en referencia al conocimiento en medidas de bioseguridad, obtuvieron el nivel de regular, y lo que respecta a la aplicación de medidas de bioseguridad, ambos grupos lograron el nivel de bueno. / Objective: Compare the level of knowledge and application of biosafety measures in undergraduate and graduate students of the 2013-2018 dental career of a Peruvian private university. Materials and Methods: A descriptive, observational cross-sectional pilot study, with the population being undergraduate and graduate students of the dental career of a Peruvian private university. A sample of 32 undergraduate students and 32 graduates of dentistry from the same institution were taken, assessing the level of knowledge through a self-applying survey and the level of application of biosecurity measures through an observational record. Univariate analysis was obtained by absolute and relative frequencies; The Chi-square test and Fisher's exact test were used for the bivariate analysis. (p≤0.05) Results: The knowledge on biosecurity measures of undergraduate and graduate students is of a regular level, with values ​​of 40.6% and 46.8% respectively, 34.37% of undergraduate students and 25.56% of the group of graduates obtained a good level of application of biosecurity measures. Statistically significant differences were found between the level of knowledge of undergraduate and graduate students. (p = 0.001). Conclusion: Undergraduate and graduate groups in reference to knowledge in biosecurity measures, obtained the level of regular, and with regard to the application of biosecurity measures, both groups achieved the level of good. / Tesis

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No description available.