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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.
611

Nominal Molecular Weight Distributions of Color, TOC, TTHM, Precursors and Acid Strength in a Highly Organic Potable Water Source

Fouroozi, Jalil 01 January 1980 (has links) (PDF)
This research investigated the relationships between molecular size and the TOC, TTHM, acid strength and color concentrations present in raw and coagulated water from Lake Washington. Three separate coagulants were utilized for investigation. There were: Al, Fe and Mg. Results indicated that the majority of the TOC, color and TTHM precursors were in the colloidal size range and removed by coagulation. The remaining TTHM precursors are mostly molecular and require a process other than coagulation for removal from the potable water before environmental standards are met.
612

Nitrogen Transformation in Secondary Wastewater Treatment Plants

Morris, Mark Lee 01 January 1975 (has links) (PDF)
Nitrogen is an essential nutrient for plant and animal life; however, its presence in concentrations exceeding assimilative capacities of receiving water bodies is undesirable. Therefore, the form and concentration of total nitrogen released in wastewater effluents is of great concern. During the course of this study, the nitrogen analysis was performed on the various unit processes of the Florida Technological University wastewater treatment plant. The average percent removal of nitrogen between plant influent and clarifier effluent was 30.5% during the month of August 1975. It is believed that the nitrogen removal is attributed to luxury uptake by the biomass through the plant. The clarifier effluent was highly nitrified containing an average ammonia nitrogen concentration of 0.76 milligrams per liter and a nitrate nitrogen concentration of 16.47 milligrams per liter. The extent to which nitrification took place was 93 - 98% with an average of 96.5% for the month of August.
613

Quantifying The Linkages Between US' Water Resources And Its Production Of Food, Energy, And Water

Ao, Yufei 25 May 2023 (has links)
Water is a critical resource that is essential for human well-being and economic development. Many regions around the world face ongoing water scarcity and competition over water resources. Climate change, other drastic social changes, and population and economic growth can significantly impact the supply and consumption of water. There has been an increasing body of research focusing on the Food-Energy-Water (FEW) nexus. There is a mismatch between the spatial resolution of data availability and the resolution that water resources follow. Lack of quality sub-county water data also makes the research of micro-level food-water dynamics difficult if not impossible. These challenges pose obstacles to the further understanding of water scarcity in the context of the FEW nexus and leaves critical gaps in the research of the nexus. In this dissertation I asked and answered the question: how do socio-economic forces shape localized groundwater depletion and surface water scarcity within the United States at the field and basin scale? Specifically, I tested whether irrigated farm size leads to reduction in groundwater application per unit area and whether an increase in the annual depletion in the underlying aquifer storage increases the probability of an irrigated land transfer, with a Kansas field level dataset and an econometrics approach. I estimated the FEW production and the water footprint of FEW production in every US watershed and compare the water footprint of production against their water scarcity. Then the groundwater reserves and dam storage in watersheds were examined as the buffers for the watersheds' FEW production against water shortages. I mapped the transfers of FEW goods and services and both the virtual and physical water flows from watersheds to US cities. The transportation infrastructure and other infrastructure that supports the FEW transfers are analyzed in terms of their contributions to the movement of FEW goods. This dissertation improves our understanding of how broad structural changes within the agricultural industry are interconnected with the overexploitation of groundwater resources. It is the first study of water footprint accounting with the most recent input data for the whole US food-energy-water system at the watershed level and includes an analysis of cities' infrastructure reliance for food-energy-water transfers and infrastructure as buffers. The transfers of virtual water and physical water were compared. The resulting data and findings from the novel data synthesis will provide insights for consumers, food companies, and other decision-makers at various levels on their connection to water resources in non-local areas. The outcomes of this dissertation will also improve our ability to analyze drivers and solutions to local small-scale watershed water scarcity challenges and allow a quantifiable basis for policy support in the water resources management domain and beyond. / Doctor of Philosophy / Water is an important resource for humans and the economy, but many regions around the world face ongoing water shortages and competition over the limited water resources. The Food-Energy-Water (FEW) nexus has gained increasing attention as a framework for understanding the complex relationships between water, food, and energy systems. However, research in this area has faced challenges in data availability and data resolution. This dissertation addresses these challenges while exploring how socio-economic forces shape localized groundwater depletion and surface water scarcity within the United States at the field, basin, and city scales. The author tests hypotheses related to irrigated farm size, irrigation water use, groundwater depletion, and the irrigated land transfers. The author estimates the FEW production and water footprint of production in every US watershed. The author also tracks and analyzes the transfers of FEW goods and services and embedded water footprint. Infrastructure's role in delivering FEW goods and buffering against water shortages were also examined. Overall, this dissertation provides insights into the connections between water resources and broad structural changes within the food system, and offers a novel data synthesis that can facilitate the understanding of connections between production and consumption of FEW at various spatial scales and water resources in local and non-local areas. The findings will also help analyze the drivers and solutions to local small-scale watershed's water scarcity challenges, and provide a quantifiable basis for policy support in the water resources management domain and beyond.
614

Susceptibility of Various Bacterial Species to Standard Purification Processes

Murad, John Louis 08 1900 (has links)
This thesis investigates the susceptibility of various bacterial species to standard purification process.
615

A lime softening system for individual-household use powered by solar energy

Unknown Date (has links)
A study conducted by the World Health Organization and United Nations Children's Fund, concluded that approximately 768 million people worldwide are not receiving sanitary drinking water suitable for consumption. While there are many water treatment methods, lime softening proves to be one of the more effective approaches as it removes a wide variety of harmful compounds including arsenic, lead, mercury, and cadmium under the correct conditions. The greatest issues with lime softening on a smaller scale include the complexity of the chemistry and need for monitoring. By designing the system for groundwater sources and with a smaller capacity, this thesis hoped to reduce the level of monitoring, chemical expertise, and cost needed for operation. While promising results occurred in the removal of arsenic and total hardness, this project was unable to obtain consistent results and final water samples with pH values between the recommended standard of 6.5 to 8. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
616

Comparison of water quality between sources and between selected villages in the Waterberg District of Limpopo Province; South Africa: with special reference to chemical and microbial quality.

Makgoka, Seretloane Japhtaline January 2005 (has links)
Thesis (MPH)--University of Limpopo, 2005 / Water and sanitation inadequacy is still an environmental health challenge in several regions worldwide and a billion people lack access to safe water, while 2.4 billion people have inadequate sanitation [2]. Assessment of water quality by its chemistry includes measures of elements and molecules dissolved or suspended in water. Commonly measured chemical parameters include arsenic, cadmium, calcium, chloride, fluoride, total hardness, nitrate, and potassium [16]. Water quality can also be assessed by the presence of waterborne microorganisms from human and animals’ faecal wastes. These wastes contain a wide range of bacteria, viruses and protozoa that may be washed into drinking water supplies [21]. Three villages were selected for water quality analysis, based on their critical situation regarding access to water and sanitation: namely, Matlou, Sekuruwe and Taolome villages, situated in the Mogalakwena Local Municipality within the Waterberg district of the Limpopo Province, South Africa. A proposal was written to the Province of North Holland (PNH) and was approved for funding to start with the implementation of those projects, with 20% of each village’s budget allocated for water quality research [26]. This was a cross sectional, analytical study to investigate the chemical and microbial quality of water in Matlou, Sekuruwe and Taolome villages. The study was also conducted to explore methods used by household members to store and handle water in storage tanks. Water samples were collected and analysed according to the standard operating procedures (SOPs) of the Polokwane Municipality Wastewater Purification Plant in Ladanna, Polokwane City of South Africa. The questionnaire used was adopted from the one used for cholera outbreak in the Eastern Cape Province of South Africa. Results show that water from all sources in all the villages had increased total hardness concentration. Water from the borehole in Matlou village had increased number of total coliform bacteria. There were increased total and faecal coliform bacteria in storage tanks samples from Matlou village. Water samples from reservoirs in Sekuruwe and Taolome villages did not test positive for any microbial contamination. Water from xiv informally connected yard taps in Sekuruwe village had increased total coliform bacteria, while increased total and faecal coliforms were found in households’ storage tanks. Water samples from communal taps in Taolome village had minimal number of total coliform bacteria, while water from storage tanks had both increased total and faecal coliform bacteria. Matlou village was the only place with increased nitrate concentration at the households’ storage tanks. While all the villages had microbial contamination, Taolome village had the least number of coliform bacteria in water samples from households’ storage tanks as compared to Matlou and Sekuruwe villages. It is concluded that water from sources supplied by the municipalities are safe to be consumed by humans while water from informally connected taps and households’ storage tanks are not safe to be used without treatment. It is recommended that a health and hygiene education package be prepared for all the villages, so that handling of water from the main source into their storage tanks can be improved. Secondly, it is recommended that water in all sources be treated for total hardness and water in storage tanks in Matlou village be treated for nitrate. Thirdly, it is recommended that water be accessed everyday of the week, so that people do not use unsafe water supplies. / The Province of North Holland, Netherlands.
617

A measure of service quality on water in Lepelle-Nkumpi Municipality in the Limpopo Province

Shongwe, Nkosinathi Sipho January 2007 (has links)
Thesis (MBA.) -- University of Limpopo, 2007 / The residents of Lebowakgomo in Lepelle-Nkumpi Municipality experience numerous inequalities in relation to water services provision. Some of the residents protest towards the inequalities through refusal to pay for the water services. The confrontational non paying residents field questions which the municipality can hardly answer. The problem of refusal to pay is of the magnitude that recently the municipality had to go house-to-house pleading with the inhabitants to pay if the municipality was to continue to provide water services. The specific objectives of this study were three-fold: (1) to determine water service quality using residents’ perceptions on water services in Lebowakgomo, (2) to determine residents’ expectations and perceptions on water services in Lebowakgomo, and (3) to determine the residents’ perceptions on water service quality and customer satisfaction in Lebowakgomo using age, gender, qualification and suburb. A questionnaire comprising five dimensions, namely, tangibles, reliability, assurance, empathy and responsiveness, was compiled to collect data from three suburbs of Lebowakgomo in Lepelle-Nkumpi Municipality. The original sample size was 120, with 9 becoming spoiled due to missing data. The independent variables comprised age, qualification, suburb and gender. Most of the data were analysed for kurtosis and skewness and with the exception of one variable, the rest of the data did not conform to parametric analysis criteria. The major findings of this study indicated overall negative perceptions of residents’ on four dimensions of empathy, reliability, responsiveness and assurance on water service quality which implied that the residents were dissatisfied with the service and called on management to use SERVQUAL as a valid model of assessment to identify areas requiring immediate attention for service improvement. On the other contra positive it was revealed that the municipality was doing well on the tangibles dimension. ix The study recommended use of SERVQUAL in measuring quality of other services within the constitutional competencies of the municipality and further research to investigate age contribution to service quality.
618

The politics of water institutional reform in neopatrimonial states : a comparative analysis of Kyrgyzstan and Tajikistan /

Sehring, Jenniver. January 2009 (has links)
Thesis (doctoral)--FernUniversität, Hagen, 2007. / Includes bibliographical references and sources.
619

Riparian buffer function with respect to nitrogen transformation and temperature along lowland agricultural streams in Skagit County, Washington /

Monohan, Carrie Elise. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 84-94).
620

A risk assessment of Northwest Christchurch water supply : systematic review of lead contaminants : a dissertation submitted in fulfilment of the requirements for the degree of Masters [ie. Master] of Health Sciences /

Lim, Elena. Unknown Date (has links)
Thesis (M. Heal. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 85-88). Also available via the World Wide Web.

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