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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

An Assessment of the Quality of Domestic Drinking Water in Kumul, Xinjiang Province, China

Yunusi, Dilibai 27 November 2013 (has links)
The purpose of this research was to improve understanding of the quality of drinking water for domestic consumption in the City of Kumul, China. The guidelines for drinking water testing in the City of Kumul were assessed and compared with actual practices. Local households in the urban center were interviewed in order to assess public attitudes towards drinking water. The results showed that the quality of treated water did not pose a direct threat to human consumers, but there were opportunities for improvements in the areas of source water protection, water treatment processes, and communication between authorities and the public. 74% of urban households personally treated their tap water prior to consumption, most commonly by boiling, to improve drinking water quality. It is recommended that the local government should seek to improve communication between the water treatment authority and the public to ensure water quality in the City of Kumul.
2

Impact of destratification on the treat-ability of natural organic matter in drinking water reservoirs.

Linden, Leon Gareth January 2008 (has links)
Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The aim of this study was to describe the potential impact of stratification, and therefore destratification, and inflow hydrodynamics on the raw water quality in drinking water reservoirs, from the perspective of NOM. Investigations of the changes in the concentration, character and removal of NOM by conventional treatment processes during inflow hydrodynamics and thermal stratification were performed using observational and manipulative experiments and empirical and process based modelling. Further conceptual models were developed in place NOM within the existing frameworks of reservoir management from the perspective of other water quality hazards. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1321572 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
3

Impact of destratification on the treat-ability of natural organic matter in drinking water reservoirs.

Linden, Leon Gareth January 2008 (has links)
Title page, contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The aim of this study was to describe the potential impact of stratification, and therefore destratification, and inflow hydrodynamics on the raw water quality in drinking water reservoirs, from the perspective of NOM. Investigations of the changes in the concentration, character and removal of NOM by conventional treatment processes during inflow hydrodynamics and thermal stratification were performed using observational and manipulative experiments and empirical and process based modelling. Further conceptual models were developed in place NOM within the existing frameworks of reservoir management from the perspective of other water quality hazards. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1321572 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008
4

An Analysis of the Microbial Quality of Packaged Water in Four Sites in Latin America

Feeser, Karla 13 May 2016 (has links)
INTRODUCTION: Diarrheal disease contributes to an estimated 1.5 million deaths each year, including 760,000 deaths among children under the age of five. Of those, approximately 500,000 are attributable to inadequate drinking water. In areas where piped water is unsafe, unreliable or economically impossible, packaged water sold by private vendors can play an important role in meeting the water needs of these populations. As the activity and importance of packaged water vendors grow, more data is needed to assess the quality of water sold, and to inform policies that regulate the private water sector throughout the world. AIM: This pilot study seeks to identify factors that may contribute to the deterioration of packaged water quality. METHODS: Small packaged water enterprises (SWEs) operating in the following cities were visited twice between May 2014 and September 2015: La Paz, Bolivia; Tegucigalpa, Honduras; and Muisne and Tena, Ecuador. A brief survey was conducted with each distributor, and a facility tour was completed. Water samples were collected directly from the purification system and water packaged in both reusable and disposable containers were purchased. Samples were tested for total coliform and E. coli bacterial contamination on the day of collection and over the course of 28 days. Data was analyzed using descriptive statistics, including median as the measure of central tendency, and frequency where the main outcome was presence or absence of either total coliform bacteria or E. coli. To determine the factors that were most associated with water quality deterioration, logistic regression was performed. RESULTS: A total of 616 samples were collected. This study found that 52% of the packaged water examined was contaminated with total coliform bacteria. Raw, untreated water and treated water packaged in reusable containers were most likely to be contaminated with total coliform bacteria and E.coli compared to treated water taken directly from the system. There was no significant association between water treatment or bottle disinfection protocols and total coliform or E. coli contamination. DISCUSSION: The study succeeded in identifying at what stage and in what type of container water is most likely to be contaminated with bacterial water-quality indicators. Furthermore, it highlights the heterogeneity that exists in terms of types of water sold, water treatment systems, and sanitizing protocols among SWEs in Central and South America. Reusable containers are vulnerable to contamination with total coliform bacteria and E. coli, even when filled with clean water, thus the contamination may be due to inadequate disinfection between uses. These results may have implications for national or international policies that regulate private water enterprises, and can inform guidelines for packaged water distributors in particular. Further research is needed to identify optimal cleaning methods for reusable containers that are practical for use in lower resource settings.
5

Photocatalysis of aquatic humic substances prior to chlorination

Palmer, Fiona Lorraine January 1998 (has links)
No description available.
6

The farm-level impact of policies to reduce nitrate emission from livestock waste : an economic analysis

Branson, Johannah Helen January 1995 (has links)
No description available.
7

Impact of an Epoxy Pipe Lining Material on Distribution System Water Quality

Pierce, Ryan Michael 16 June 2009 (has links)
Corrosion of iron and copper pipes can produce leaks and loss of efficiency in the water distribution system, elevate levels of contaminants at the tap, and cost billions of dollars annually in pipe replacement or rehabilitation. In situ pipe rehabilitation using cement mortar, polyurethane, and epoxy is a commonly employed method of dealing with aging yet structurally sound pipes because it is less expensive and less invasive than replacing pipe infrastructure. Although epoxy has been shown to be an effective solution to pipe corrosion, little research has been conducted regarding its impact on a comprehensive list of water quality parameters. This research addressed that gap in the literature by conducting short-term immersion tests in which new epoxy linings were exposed to reference tap waters containing one of three disinfectant treatments: no disinfectant, free chlorine, or chloramines. As a comparison, an aged epoxy-lined field sample was also tested. Water exposed to the liners under stagnant conditions was analyzed for the following water quality parameters: pH, ammonia, alkalinity, hardness, metals, disinfectant consumption, total organic carbon (TOC), semi-volatile organic compounds (SVOCs), disinfectant byproduct (DBP) formation, and odor. Results of the study showed relatively low impacts on water quality, as all USEPA drinking water regulations were met. Impacts were highest during the first 24 hour exposure period during which time significant disinfectant consumption was shown (> 90% free chlorine consumed, 13% chloramines consumed), high TOC was leached (2.6-6.2 mg/L), trihalomethanes and haloacetic acids were formed (both < 15 ug/L), Bisphenol-A, an endocrine disrupter, was detected (< 35 ug/L), and odor was reported by panelists at a moderate intensity and described as sweet/chemical/burning/chlorinous. Impacts were much less after the initial 24 hours, although odor remained noticeable throughout the 30 day study. Overall, water quality impacts were greatest in chlorinated waters and both new and aged epoxy showed slight differences in results. / Master of Science
8

Assesment of drinking water quality using disinfection by-products in a distribution system following a treatment technology upgrade

Bush, Kelly Lynn 05 1900 (has links)
Chlorine is the most widely used disinfectant for drinking water treatment. Chlorine canreact with natural organic matter (NOM) in water sources resulting in the formation of potentially carcinogenic disinfection by-products (DBPs). The most common DBPs measured in chlorinated drinking water distribution systems are trihalomethanes (THMs) and haloacetic acids (HAAs). In 2005, the City of Kamloops, British Columbia upgraded the drinking water treatment system to ultrafiltration membrane treatment. The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. This study used a two-phase research approach. Phase I of the study was a distribution system monitoring program that collected water samples and physical and chemical information using data loggers at five sampling sites within the distribution system. Phase II of the study used bench-scale simulations that modeled DBP formation using a flow-through reactor system, the material-specific simulated distribution system (MS-SDS), constructed of pipe material resurrected from the City of Kamloops distribution system. Phase I results suggested that implementation of the ultrafiltration treatment process and accompanying treatment system upgrade was not effective at reducing the concentration of DBPs delivered to consumers. Concentrations of THMs remained relatively constant at sampling sites, while concentrations of HAAs increased following implementation of the ultrafiltration treatment process. The increase in HAA formation was likely due to an increase in retention time of the water within the distribution system following implementation of the ultrafiltration treatment process, rather than due to the treatment process itself. The results of this study are consistent with previous work on South Thompson River water DBP precursors, which suggested that THM and HAA precursors of this source water are small and hydrophilic, and therefore cannot be removed by ultrafiltration processes. Phase II results showed that the MS-SDS was more representative of distribution system c onditions than traditional glass bottles to estimate DBP formation. It is recommended that the MS-SDS be used in parallel with a simultaneous distribution system monitoring program to estimate distribution system retention times from THM and HAA concentrations.
9

Microbial drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa / Wernich Foit

Foit, Wernich January 2007 (has links)
Safe drinking water is a basic human right. This study mainly focused on the physicochemical and microbiological drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa. Parameters measured to determine the physico-chemical quality of drinking water were temperature, pH, total dissolved solids (TDS), electric conductivity, carbonate hardness, total hardness, NO2 -, NO3 - and chlorine. These parameters indicated hard water in the informal settlement (Sonderwater) as well as in the rural area (Ganyesa). Nitrate content were troubling for both areas, and total dissolved solids were higher than the standard in the water from Ganyesa. For microbiological quality of the water, heterotrophic plate count (HPC) bacteria, total coliforms, faecal coliforms, faecal streptococci, and staphylococci were enumerated on appropriate selective media using standard procedures. In the water from Sonderwater, faecal indicator bacteria were isolated, but none were found in the water from Ganyesa. Heterotrophic plate count bacteria and total coliforms were detected at levels above the standard in water samples from both areas. Staphylococci and faecal streptococci were present in low numbers in the water from both sites. Faecal coliforms isolated from Sonderwater showed multiple antibiotic resistances to beta-lactams. Identification of faecal coliforms from Sonderwater by API 20E strips and sequencing showed that they were Aeromonas spp. and Enterobacter spp.. Bacteria in the water from Sonderwater were tested for the potential to form biofilms. Scanning electron microscopy revealed multi-species biofilms developing in the water container after 5 days of storage. Water was sampled from four areas outside of Potchefstroom to determine a settlement gradient in water quality. Areas ranged from a formal area, through an established informal area and a newly established informal area to the newest established informal area. The water from these areas was classified as hard according to physico-chemical parameters measured, and TDS for the water from all areas were above the standard for domestic use. The established informal area had high numbers of total coliforms present in the water. Staphylococci and HPC bacteria were detected in levels higher than the standard for domestic use in all water samples. No faecal coliforms were found in the water from any of the areas. There was no visible gradient in the water quality between the areas. The water samples collected from rural, peri-urban and urban schools were also analysed in terms of physico-chemical and microbiological parameters. Water from all schools was classified as hard water. Only one school (peri-urban) had a pH above the standard. One rural school and one peri-urban school had TDS and electrical conductivity levels above the standard for domestic use. All rural and peri-urban schools had alarmingly high levels of nitrates present in the water. These schools receive groundwater as drinking water. Total coliform bacteria were present at high levels in all water samples from the schools. Rural and peri-urban schools presented levels of staphylococci and HPC bacteria higher than the standard for domestic use. Streptococci were present in water from some of the rural and peri-urban schools and one urban school. Faecal coliform/faecal streptococci ratios for rural schools indicated faecal pollution potentially of human origin, and in other schools faecal pollution from both human and animal origin. Before the vacation, faecal coliform bacteria were detected in water from all rural schools, two peri-urban schools and one urban school. After the vacation, faecal coliforms were only detected in water from two rural schools and one peri-urban school. Faecal coliforms identified and characterized showed multiple antibiotic resistances to beta-lactams, oxy-tetracycline and trimethoprim. Identification by API 20E strips and sequencing confirmed that faecal coliforms from schools were Escherichia coli and Klebsiella spp. It was concluded that water from Sonderwater were of poor quality and water from Ganyesa were acceptable with only the nitrates a troubling factor. There was no settlement gradient observed in terms of water quality between areas. Water from rural schools were generally of unacceptable quality in terms of both physico-chemical and microbiological parameters. The water quality of these schools was also very poor when compared to urban schools. Periurban schools had water quality better than rural schools, but poorer than urban schools. Surveys of water quality are recommended for all areas sampled, and education on the sanitary quality of water and related health implications is advisable for residents of informal and rural areas. / Thesis: B.Sc. Microbiology and Biochemistry School of Environmental Science and Development Faculty of Natural Sciences North-West University: Potchefstroom campus 2006.
10

Microbial drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa / Wernich Foit

Foit, Wernich January 2007 (has links)
Safe drinking water is a basic human right. This study mainly focused on the physicochemical and microbiological drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa. Parameters measured to determine the physico-chemical quality of drinking water were temperature, pH, total dissolved solids (TDS), electric conductivity, carbonate hardness, total hardness, NO2 -, NO3 - and chlorine. These parameters indicated hard water in the informal settlement (Sonderwater) as well as in the rural area (Ganyesa). Nitrate content were troubling for both areas, and total dissolved solids were higher than the standard in the water from Ganyesa. For microbiological quality of the water, heterotrophic plate count (HPC) bacteria, total coliforms, faecal coliforms, faecal streptococci, and staphylococci were enumerated on appropriate selective media using standard procedures. In the water from Sonderwater, faecal indicator bacteria were isolated, but none were found in the water from Ganyesa. Heterotrophic plate count bacteria and total coliforms were detected at levels above the standard in water samples from both areas. Staphylococci and faecal streptococci were present in low numbers in the water from both sites. Faecal coliforms isolated from Sonderwater showed multiple antibiotic resistances to beta-lactams. Identification of faecal coliforms from Sonderwater by API 20E strips and sequencing showed that they were Aeromonas spp. and Enterobacter spp.. Bacteria in the water from Sonderwater were tested for the potential to form biofilms. Scanning electron microscopy revealed multi-species biofilms developing in the water container after 5 days of storage. Water was sampled from four areas outside of Potchefstroom to determine a settlement gradient in water quality. Areas ranged from a formal area, through an established informal area and a newly established informal area to the newest established informal area. The water from these areas was classified as hard according to physico-chemical parameters measured, and TDS for the water from all areas were above the standard for domestic use. The established informal area had high numbers of total coliforms present in the water. Staphylococci and HPC bacteria were detected in levels higher than the standard for domestic use in all water samples. No faecal coliforms were found in the water from any of the areas. There was no visible gradient in the water quality between the areas. The water samples collected from rural, peri-urban and urban schools were also analysed in terms of physico-chemical and microbiological parameters. Water from all schools was classified as hard water. Only one school (peri-urban) had a pH above the standard. One rural school and one peri-urban school had TDS and electrical conductivity levels above the standard for domestic use. All rural and peri-urban schools had alarmingly high levels of nitrates present in the water. These schools receive groundwater as drinking water. Total coliform bacteria were present at high levels in all water samples from the schools. Rural and peri-urban schools presented levels of staphylococci and HPC bacteria higher than the standard for domestic use. Streptococci were present in water from some of the rural and peri-urban schools and one urban school. Faecal coliform/faecal streptococci ratios for rural schools indicated faecal pollution potentially of human origin, and in other schools faecal pollution from both human and animal origin. Before the vacation, faecal coliform bacteria were detected in water from all rural schools, two peri-urban schools and one urban school. After the vacation, faecal coliforms were only detected in water from two rural schools and one peri-urban school. Faecal coliforms identified and characterized showed multiple antibiotic resistances to beta-lactams, oxy-tetracycline and trimethoprim. Identification by API 20E strips and sequencing confirmed that faecal coliforms from schools were Escherichia coli and Klebsiella spp. It was concluded that water from Sonderwater were of poor quality and water from Ganyesa were acceptable with only the nitrates a troubling factor. There was no settlement gradient observed in terms of water quality between areas. Water from rural schools were generally of unacceptable quality in terms of both physico-chemical and microbiological parameters. The water quality of these schools was also very poor when compared to urban schools. Periurban schools had water quality better than rural schools, but poorer than urban schools. Surveys of water quality are recommended for all areas sampled, and education on the sanitary quality of water and related health implications is advisable for residents of informal and rural areas. / Thesis: B.Sc. Microbiology and Biochemistry School of Environmental Science and Development Faculty of Natural Sciences North-West University: Potchefstroom campus 2006.

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