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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Water quality and sanitation in rural Moldova / Vattenkvalitet och sanitet på Moldaviens landsbygd

Hugosson, Hanna, Larnholt, Katja January 2010 (has links)
<p>Because of the impact on human health and sustainable livelihood, the topic of drinking water and sanitation facilities is becoming a seriously discussed issue among international organizations as well as developing agencies in industrialized countries. The importance of water and sanitation management initialized this master thesis.</p><p> </p><p>The aim of the project is to do an assessment of the drinking water quality as well as the sanitation situation in the village Condrita in the Republic of Moldova. This was done by studying the existing water and sanitation facilities, sampling the water, evaluating the reason for the poor water quality and mapping the current situation using ArcGIS. Furthermore, technologies for improving the drinking water and sanitation facilities are suggested.</p><p> </p><p>The work was carried out by doing a literature study on how water sources and sanitation facilities should be constructed in order to ensure people’s health and to meet their needs. Geographic coordinates and water samples were collected from twenty-two public wells and springs. Interviews on the water situation and sanitation facilities were performed. Furthermore, water samples were analysed with respect to nitrate, turbidity, electrical conductivity and coliform bacteria amongst others. Pesticide contamination was also taken into consideration when one of the wells was analysed. Water sources were classified as improved or unimproved according to definitions by WHOSIS. Moreover, the DRASTIC vulnerability model was used to evaluate the groundwater susceptibility to contaminants.</p><p> </p><p>In general, the water quality in the study area was poor and measured values of the analyzed parameters exceeded international or Moldovan standards for nitrate, hardness, electrical conductivity and total coliform bacteria. Four wells were contaminated with <em>E. coli</em> bacteria. Furthermore, turbidity measurements exceeded Moldovan standards in seven out of twenty-two water sources. No pesticide contamination was detected. Sampled water from the densely populated parts of the village as well as unimproved water sources proved to be of poorer quality. Map results showed that a majority of the groundwater within the study area was subject to a moderate or high risk of becoming contaminated. The current sanitation situation is that most families use simple pit latrines, which are placed far away from the dwelling-houses. Digging a new toilet when the existing one is full is a common practice in Condrita. Hand-washing facilities are seldom placed in proximity to the toilets.</p><p> </p><p>Pit latrines are believed to be the most important source of groundwater contamination in the study area. Other sources are agricultural activities and poor practice when abstracting water from the wells. A feasible solution to improve both the drinking water quality and the sanitation situation would be to install ecosan toilets. Improvements of the well’s features that are suggested include construction of an apron slab as well as proper lids for covering the well.</p>
2

Water quality and sanitation in rural Moldova / Vattenkvalitet och sanitet på Moldaviens landsbygd

Hugosson, Hanna, Larnholt, Katja January 2010 (has links)
Because of the impact on human health and sustainable livelihood, the topic of drinking water and sanitation facilities is becoming a seriously discussed issue among international organizations as well as developing agencies in industrialized countries. The importance of water and sanitation management initialized this master thesis.   The aim of the project is to do an assessment of the drinking water quality as well as the sanitation situation in the village Condrita in the Republic of Moldova. This was done by studying the existing water and sanitation facilities, sampling the water, evaluating the reason for the poor water quality and mapping the current situation using ArcGIS. Furthermore, technologies for improving the drinking water and sanitation facilities are suggested.   The work was carried out by doing a literature study on how water sources and sanitation facilities should be constructed in order to ensure people’s health and to meet their needs. Geographic coordinates and water samples were collected from twenty-two public wells and springs. Interviews on the water situation and sanitation facilities were performed. Furthermore, water samples were analysed with respect to nitrate, turbidity, electrical conductivity and coliform bacteria amongst others. Pesticide contamination was also taken into consideration when one of the wells was analysed. Water sources were classified as improved or unimproved according to definitions by WHOSIS. Moreover, the DRASTIC vulnerability model was used to evaluate the groundwater susceptibility to contaminants.   In general, the water quality in the study area was poor and measured values of the analyzed parameters exceeded international or Moldovan standards for nitrate, hardness, electrical conductivity and total coliform bacteria. Four wells were contaminated with E. coli bacteria. Furthermore, turbidity measurements exceeded Moldovan standards in seven out of twenty-two water sources. No pesticide contamination was detected. Sampled water from the densely populated parts of the village as well as unimproved water sources proved to be of poorer quality. Map results showed that a majority of the groundwater within the study area was subject to a moderate or high risk of becoming contaminated. The current sanitation situation is that most families use simple pit latrines, which are placed far away from the dwelling-houses. Digging a new toilet when the existing one is full is a common practice in Condrita. Hand-washing facilities are seldom placed in proximity to the toilets.   Pit latrines are believed to be the most important source of groundwater contamination in the study area. Other sources are agricultural activities and poor practice when abstracting water from the wells. A feasible solution to improve both the drinking water quality and the sanitation situation would be to install ecosan toilets. Improvements of the well’s features that are suggested include construction of an apron slab as well as proper lids for covering the well.
3

Temporal Trends of Coliform Bacteria in Spencer Creek, Hamilton

Lymburner, Donna J. 04 1900 (has links)
<p> Coliform bacterial pollution was studied in the Spencer Creek in Hamilton, Ontario. Data, derived from the Ontario Ministry of the Environment files in Hamilton, were used in the determination of whether distinctive temporal patterns of coliform bacterial counts and loads exist in Spencer Creek at Cootes Drive in Dundas. An initial investigation of the general streamflow trends showed that the peak flow period is during the spring snowmelt (March) and a secondary peak flow occurs in late fall due to frontal storms passing through the area. This coincides with the minimums of coliform counts and loads which consistently occur during these times of high flow, particularly March and April. Peak coliform counts and loads occur 70% of the time in late summer with varying starting times in June, July, August and September. This is attributed to the low flow and high temperature of the water in the summer. The average coliform count is 334,154 coliform bacteria per 100 mL water, well above the water quality objectives set by the Ontario Water Resources Commission for Ontario Ministry of the Environment. Approximately 80% of the coliform counts, measured in Spencer Creek in this study, were well above this water quality objective. Therefore, in terms of coliform bacteria, Spencer Creek is polluted, particularly in the summer months. This study simply points out the necessity for further study and continued water quality testing in Spencer Creek.</p> / Thesis / Candidate in Philosophy
4

Evaluation of Well Seal Integrity and Its Relative Importance in Assessing Groundwater Quality

St-Germain, Pascale L. 25 November 2011 (has links)
Unlike municipal water supplies, provincial regulations do not require systematic testing of domestic well water, which may adversely impact local residents should contamination occur. Private wells are typically shallow relative to municipal wells, and thus, are particularly vulnerable to sources of surficial contamination if preferential recharge pathways such as natural fractures or faulty seals are present. In order to determine the relative importance of well seal integrity as a preferential pathway, a practical detection method was developed based on infiltrometry. This method successfully detected faulty well seals in a wide range of geological settings across Canada, including: Hobbema, Alberta; Lindsay, Ontario; and Chelsea, Québec. It was most successful in areas of minimal heterogeneity and where the surficial geology is composed of fine-grained sediments. The community of Chelsea (Québec) was also the primary study site to examine a range of factors affecting water quality including physical characteristics, faulty well seals, other anthropogenic activities and seasonality. Water samples were collected over a period of 14 months and analyzed for bacteria and major-ion chemistry. The results show that the consideration of physical features alone is not enough to predict vulnerability in the study area. Seasonal fluctuations in ionic concentrations (e.g. ionic strength, NO3-N and Cl-) and coliform bacteria are observed and result from disperse and rapid recharge events. Multivariate analysis techniques (e.g. principal components analysis and hierarchical cluster analysis) demonstrate that preferential recharge pathways and anthropogenic activities, such as domestic effluents affect the groundwater quality. The data and findings of this study were used to assist in the design of a probabilistic risk assessment model based on the Poisson distribution. This study demonstrates the complexity and the challenges related to bacterial contamination in drilled wells. In spite of these challenges, this analysis was useful as a baseline to assess the impact of anthropogenic activities, and may be used in future studies to assist municipalities in the evaluation and protection of groundwater supplies.
5

Evaluation of Well Seal Integrity and Its Relative Importance in Assessing Groundwater Quality

St-Germain, Pascale L. 25 November 2011 (has links)
Unlike municipal water supplies, provincial regulations do not require systematic testing of domestic well water, which may adversely impact local residents should contamination occur. Private wells are typically shallow relative to municipal wells, and thus, are particularly vulnerable to sources of surficial contamination if preferential recharge pathways such as natural fractures or faulty seals are present. In order to determine the relative importance of well seal integrity as a preferential pathway, a practical detection method was developed based on infiltrometry. This method successfully detected faulty well seals in a wide range of geological settings across Canada, including: Hobbema, Alberta; Lindsay, Ontario; and Chelsea, Québec. It was most successful in areas of minimal heterogeneity and where the surficial geology is composed of fine-grained sediments. The community of Chelsea (Québec) was also the primary study site to examine a range of factors affecting water quality including physical characteristics, faulty well seals, other anthropogenic activities and seasonality. Water samples were collected over a period of 14 months and analyzed for bacteria and major-ion chemistry. The results show that the consideration of physical features alone is not enough to predict vulnerability in the study area. Seasonal fluctuations in ionic concentrations (e.g. ionic strength, NO3-N and Cl-) and coliform bacteria are observed and result from disperse and rapid recharge events. Multivariate analysis techniques (e.g. principal components analysis and hierarchical cluster analysis) demonstrate that preferential recharge pathways and anthropogenic activities, such as domestic effluents affect the groundwater quality. The data and findings of this study were used to assist in the design of a probabilistic risk assessment model based on the Poisson distribution. This study demonstrates the complexity and the challenges related to bacterial contamination in drilled wells. In spite of these challenges, this analysis was useful as a baseline to assess the impact of anthropogenic activities, and may be used in future studies to assist municipalities in the evaluation and protection of groundwater supplies.
6

Coliform Bacteria From A Drinking Water Distribution System: Microbial Source Tracking, Characterization And Biofilm Formation

Mosher, Mikaela 26 October 2011 (has links)
A library of 18 coliform bacteria strains was obtained from different sampling points in the drinking water distribution system in Lexington, KY, over a three month period in 2006. To investigate the cause of the coliform occurrence we conducted a microbial source tracking study using phenotypic (API 20E, Biolog, and Vitek) and genotypic (pulsed field gel electrophoresis (PFGE) and ribotyping) analyses to determine the degree of genetic variation among isolates. Characterization of isolates by PFGE and ribotyping showed that coliform events in the distribution system were related and a regrowth problem may exist due to biofilm formation. The ability of a persistent Enterobacter cloacae strain to adhere and form biofilm was found to depend on environmental conditions such as temperature, pipe material, soiled surface, chlorine and nutrient levels with higher temperatures and nutrient levels promoting adherence. Considerable variation in adherence and biofilm formation was observed among representative Enterobacter isolates.
7

Evaluation of Well Seal Integrity and Its Relative Importance in Assessing Groundwater Quality

St-Germain, Pascale L. 25 November 2011 (has links)
Unlike municipal water supplies, provincial regulations do not require systematic testing of domestic well water, which may adversely impact local residents should contamination occur. Private wells are typically shallow relative to municipal wells, and thus, are particularly vulnerable to sources of surficial contamination if preferential recharge pathways such as natural fractures or faulty seals are present. In order to determine the relative importance of well seal integrity as a preferential pathway, a practical detection method was developed based on infiltrometry. This method successfully detected faulty well seals in a wide range of geological settings across Canada, including: Hobbema, Alberta; Lindsay, Ontario; and Chelsea, Québec. It was most successful in areas of minimal heterogeneity and where the surficial geology is composed of fine-grained sediments. The community of Chelsea (Québec) was also the primary study site to examine a range of factors affecting water quality including physical characteristics, faulty well seals, other anthropogenic activities and seasonality. Water samples were collected over a period of 14 months and analyzed for bacteria and major-ion chemistry. The results show that the consideration of physical features alone is not enough to predict vulnerability in the study area. Seasonal fluctuations in ionic concentrations (e.g. ionic strength, NO3-N and Cl-) and coliform bacteria are observed and result from disperse and rapid recharge events. Multivariate analysis techniques (e.g. principal components analysis and hierarchical cluster analysis) demonstrate that preferential recharge pathways and anthropogenic activities, such as domestic effluents affect the groundwater quality. The data and findings of this study were used to assist in the design of a probabilistic risk assessment model based on the Poisson distribution. This study demonstrates the complexity and the challenges related to bacterial contamination in drilled wells. In spite of these challenges, this analysis was useful as a baseline to assess the impact of anthropogenic activities, and may be used in future studies to assist municipalities in the evaluation and protection of groundwater supplies.
8

Cereal non-starch polysaccharides in pig diets : influence on digestion site, gut environment and microbial populations /

Högberg, Ann, January 2003 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.
9

Coliform mastitis in the sow : clinical immunological studies around parturition /

Österlundh, Ingrid, January 2003 (has links)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.
10

Pathogen inactivation and regrowth in organic waste during biological treatment /

Elving, Josefine, January 2009 (has links) (PDF)
Lic.-avh. SLU : Sveriges lantbruksuniv., 2009. / Härtill 2 uppsatser.

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