Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

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No description available.

Many methods for the quantitative concentration of small amounts of viruses from natural water supplies have been considered. One of the most promising of these is the adsorption of viruses onto a 0.45pm cellulose nitrate membrane filter apparatus. A quantity of water is passed through the filter by gravity or pressure filtration. The viruses present in the water are adsorbed onto the membrane and are subsequently eluted by the use of a beef extract eluant. The virus-containing elution is then layered upon tissue culture, preferably the BGM cell line, for isolation by the plaque method. The isolated virus is then identified by serological techniques.The research presented here utilized the cellulose nitrate membrane filter system for the detection of viruses from local waterways and sewage treatment influents and effluents. Examination of the water was done for the Enterovirus group of viruses consisting primarily of the Echovirus, Coxsackievirus, and Poliovirus groups.Although viral cytopathic effect was detectable in a few cell cultures innoculated with collected water samples, no virus was isolated and identified by serological techniques or electron microscopy. The use of continuous cell lines produced numerous problems during this study. Subsequently, any viruses in positive CPE flasks could not be repassaged in BGM cultures. No viruses could be identified by neutralization in tissue culture. Identification of the positive flasks could not be made by electron microscopy.

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The objective of this research project was to investigate the influence of the principal design and operational parameters on the quality of the filtrate from a slow sand filter. These parameters are sand effectivc size, depth of sand bed, rate of filtration, water temperature and influent quality. Attempts were then made to establish relationships between the variables employed by means of regression analyses of the experimental data. To carry out the investigation three laboratory scale filter columns were constructed each measuring 150 mm in diameter and 3010 mm height. The filtration medium in each column consisted of a 1.2 m depth of sand on a 0.3 m depth of gravel. For the three individual columns three different sand sizes were employed. These were 0.17 mm effective size (ES), 0.35 mm ES and 0.45 mm ES. Water to be filtered was abstracted from the Burleigh Brook, adjacent to the Civil Engineering laboratories. As required small amounts of settled sewage, obtained from the Loughborough Water Reclamation Works, were added to increase both the turbidity and the count of indicator bacteria. The filters were operated at five different filtration rates at three different temperatures. These temperatures were 25 degrees C, 15 degrees C, 5 degrees C and the filtration rates repeated for each temperature were 0.1, 0.2, 0.3, 0.4, 0.5 m/h. The filters were operated for not less than one month at each filtration rate. In order to assess the efficiency of the filters water samples were taken and analysed from the influent and from the filtrate and also from a series of sampling taps positioned at various depth down the sand media. These water samples were tested for total coliform bacteria, for faecal coliform bacteria, suspended solids and turbidity. Regression analyses were then carried out on the data obtained and regression models were developped for 100 mm and 1200 mm sand depths of each filter for each period. Occasional tests (i. e. at least once for each flow rate) were also carried out for nitrate and ammoniacal nitrogen, colour, pH, conductivity, total organic carbon (TOC) and dissolved oxygen. Following the completion of the filtration operation at three temperatures and five filtration rates the sands of the filtration media were also examined. Sand samples were taken for examination from 0, 50, 100, 150, 200, 300, 400, 600, 800, 1000 and 1200 mm below the sand surface of each filter. Then in order to assess both the penetration of the removed solids into the filter bed and to investigate the concentration of the biological film developed within the sand bed, sand samples were analysed for suspended solids, turbidity, standard plate count bacteria and particulate organic carbon. Regression analyses were also carried out on these data and variation of each parameter against each filter bed was modelled. The solid and biological deposits on the sand samples were also viewed with a Scanning Electron Microscope.

A series of pilot and full-scale experiments were carried out at the Mannheim Water Treatment Plant in Kitchener, Ontario to examine the impact of backwash technique, filter media characteristics, and combinations thereof on single stage drinking water biological filter performance. The media characteristics investigated were effective size, uniformity coefficient, and media type (GAC and anthracite). Backwash techniques investigated were the collapsed pulse backwash, the extended terminal subfluidization wash (ETSW), and the presence of chlorine in the wash water. Single stage biological filters must serve the dual purpose of biologically mediated removal of biodegradable organic matter (BOM), as well as meeting traditional filter performance criteria such as turbidity removal with minimal head loss accumulation. Accordingly, dissolved organic carbon removal, biodegradable dissolved organic carbon removal, biological respiration potential, turbidity removal, filter ripening time, and head loss accumulation were all quantified as measures of biological filtration performance. The results of this study have several implications for optimized design and operation of biological filters during drinking water treatment. An increase in effective size of media grains from 1.0 mm to 1.3 mm was shown to significantly extend filter run time by minimizing head loss accumulation without compromising turbidity or BOM removal. Uniformity coefficient however, showed no significant effect on biological filter performance; indicating that the performance benefits associated with highly uniform media may not be commensurate with cost. GAC was found to be significantly more resilient to backwashing in collapsed pulse and chlorinated modes, which impaired BOM removal in anthracite filters. This resilience imparts a high degree of operational flexibility to backwashing GAC filters. The significant decrease in BOM removal by anthracite filters can be minimized; however, by using an optimized backwashing technique. Collapsed pulse backwashing was found to have a significant effect on biological filter performance. When chlorinated collapsed pulse was used, filter cycles were significantly shortened by approximately 30 – 50% due to a sudden surge in effluent turbidity. This effect is thought to be the result of biofilm, damaged during the course of backwashing sloughing from the media. Extended terminal subfluidization wash was found to significantly reduce, and often eliminate filter ripening entirely. Additionally, the extended contact time with chlorine associated with chlorinated ETSW did not appear to have a significant effect on filter BOM removal. By eliminating filter ripening without compromising biological performance, ETSW shows promise for significant water and production cost savings by minimizing the filter-to-waste period during filter ripening. The presence of chlorine however, was associated with decreased DOC, 24 hours in to the filter cycle. This factor, combined with the negative interaction between chlorine and collapsed pulse suggests chlorinated wash water should be avoided in biological filtration systems like the ones investigated.

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This research is a follow up to preliminary studies reported by Beier and Sego (2008) and the objective is to investigate laboratory scale dewatering of oil sands total tailings using cross flow filtration technology. A laboratory experiment was setup in Oil Sands Tailings Research Facility and tests were carried out under different operational conditions using different tailings. The experiments showed clean filtrate water generated under all test conditions. Coarser tailings and higher filter pipe porosity resulted in greater filtrate flux rate. The effect of slurry velocity, residual bitumen, and transmembrane pressure on cross flow filtration performance was also evaluated. A dimensional analysis was developed using the laboratory tests to establish the relationships between measured parameters and to assist and guide future experimental programs. / Geotechnical Engineering