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Analysis of disinfection by products in drinking water by solid phase extractionSexton, Diane Lynne 12 September 2009 (has links)
The objectives of this research were to develop a broad spectrum method for the extraction, concentration, and analysis of drinking water disinfection by products using solid phase extraction (SPE), and to determine if this method had lower detection limits and less variability than the proposed liquid-liquid extraction method, EPA Method 551. The disinfection by products investigated were halogenated nitriles, ketones, and aldehydes. The SPE method extracted and concentrated samples using the C-18 Empore Extraction Disks, and desorbed the analytes with methyl-tert-butyl ether (MTBE) as a solvent. The results showed that with the SPE method the recoveries were low (0-50%) for most compounds, and the limit of detection (LOD) values were in the range of 0.2 to 50 ug/L, which were much higher than those for EPA Method 551. The variability was also higher than for EPA Method 551. The SPE method also appeared to be concentration dependent; the recoveries decreased as analyte concentration increased. Highly saline conditions (250 g/L NaCl) resulted in low recoveries and concentration dependencies for some compounds. Even though the SPE method was easier and faster, the lower method detection limit (MDL) values and lower variability made Method 551 more preferable. Further analysis of the SPE method using a new cyclohexyl disk was also recommended. / Master of Science
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Exploring the Role of Trust in Drinking Water Systems in Western VirginiaGrupper, Madeline A. 27 August 2020 (has links)
As the impacts of global change drivers and anthropogenic influences increase, the lakes and reservoirs that communities rely on for their drinking water are threatened by more frequent, severe, and unpredictable disturbances. This study was a part of an interdisciplinary effort to understand and increase resilience in water systems to improve managers adaptive capacity to cope with these disturbances. A key element of social resilience is trust, which can improve the speed and effectiveness of management actions and can spillover into community wellbeing and behavioral outcomes, including acceptance or rejection of tap water. Using a four-stage drop off pick up method, I surveyed 611 residents in Roanoke, Virginia to examine the role of trust in drinking water systems between a community and their utility. I first focused on factors that related to a person's trust in their water utility. I examined the relationship between four determinants of trust ecology, the salience of a trusting behavior, and trust, as well as and the effects of information provision about new water security technologies on trust. I then assessed trust's role in characterizing drinking water behavior (i.e. water source usage) alongside factors of risk, water quality evaluations, and salience. I found that trust can be high in low salience situations and information provision had no effect on trust, suggesting that people might take their water security for granted when it is not at the forefront of their thoughts. Calculated beliefs about a utility's capability were only linked to increasing trust when those beliefs were negative, suggesting that people might have a threshold where their utility is capable enough to trust. Even in the absence of the information to form affinitive judgments, value and goodwill-based judgments were important to community trust. Lastly, understanding behaviors might provide indicators for managers about the state of community perceptions of their water since trust, risk perceptions, and evaluations of tap water's taste, smell, and appearance varied based on an individual's water source choice. These findings demonstrate the complexity and importance of community's trust in their water managers. This study of, and continued research into, trust can help us further our understanding of, and the tools to build, the resilient water systems needed to preserve water security and community health. / Master of Science / The raw water sources that utilities use to treat drinking water are typically lakes and reservoirs. This means that the safety of public drinking water is reliant on the stability of the surface water sources that water utilities use. Because of extreme weather, warming temperatures, and human land use, disturbances to surface lakes and reservoirs are becoming more frequent, severe, and unpredictable. A key goal of water-quality researchers is to learn how to develop systems that are more capable of adapting to these disturbances. Trust is an asset to water systems ability to handle disturbance. If people trust their water utility, they offer less resistance to new management plans and worry less about their water. To better understand trust in water utilities, I conducted a survey on residents in Roanoke Virginia. Trust in an institution is a function of an individual's calculation that their water utility can deliver safe drinking water (rational determinants), their feelings of value affinity or goodwill to their utility (affinitive determinants), their natural inclination to trust (dispositional determinants), and their belief that the water utility is regulated by a larger system of procedures (systems determinants). Trust also varies based on salience of a trusting behavior, which, in this case, was the degree to which citizens are aware of and think about their drinking water safety and supply. I assessed how these four judgments and salience relate to trust, and if providing information about new technology designed to keep water safe could increase trust. I then looked how trust interacted with other factors of risk, water quality evaluations, and people's awareness of their drinking water to characterize the perceptions of people who drink from different water sources. I found that when people have had consistent outcomes for their water security, they don't think about their water much but still have high trust that it to be safe. Providing people with information about water safety technology did not impact their trust. All four determinants had different relationships with trust. Levels of trust plateaued after neutral levels of capability beliefs and moderate levels of value and goodwill judgements were reached while broader system beliefs maintained a strong positive relationship with trust and disposition maintained a weak positive relationship with trust. Affinitive, rational, and procedural determinants were important to trust. People were more likely to drink tap water if they had higher trust in their utility, lower risk perceptions, and more favorable tap water quality evaluations. Salience, though important to trust formation, played less of a role in characterizing drinking water behavior. Overall my findings show that several factors interact together to form trust, and that trust, once formed, plays an important role in characterizing different drinking water behaviors. This study and future attempts to learn about trust can help us understand how to build water system's adaptive capabilities and preserve community health through disturbances.
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Design and evaluation of a cost effective household drinking water treatment systemMahlangu, Themba Oranso 20 August 2012 (has links)
M.Sc. / The world is focusing on increasing the number of people who have access to safe drinking water due to the ascending numbers of drinking water related illnesses reported annually in rural areas where water is not treated before consumption. To meet this goal, household water treatment has to be introduced especially in places where homes are wide apart making centralised water treatment improbable. Most readily available household water treatment systems (HWTS) such as membrane filters may not be affordable in rural areas due to power requirements and degree of ability to use and maintain them. This study was therefore aimed at designing and constructing HWTS using readily available material such as sand, gravel, zeolites and clays. Five HWTS were designed, built, evaluated and compared based on their ability to remove chemical contaminants such as iron, arsenic and fluorides from drinking water. The types of filters that were used during this study are the biosand filter (BSF), a modified biosand filter with zeolites (BSFZ), a silver impregnated porous pot (SIPP) filter, a ceramic candle filter (CCF) and a bucket filter (BF). Effectiveness of the filters in reducing physical parameters such as turbidity and visual colour was also assessed. The water treatment devices had the following flow rates; 1.74 L/h – 19.20 L/h (BSFZ), 0.81 L/h – 6.84 L/h (BSF), 0.05 L/h – 2.49 L/h (SIPP) and 1.00 L/h – 4.00 L/h (CCF). The flow rates were high at the early stages of filter use and decreased with increase in the volume of water filtered through. The flow rates of the filters were affected by the turbidity of intake water which was between 1.74 NTU – 42.93 NTU and correlated to chlorophyll a concentrations. The household water treatment technologies reduced turbidity to levels less than 1 NTU (> 90% reduction) in the following order SIPP > BSFZ > BSF > CCF > BF. The filters achieved greater than 60% retention of calcium, magnesium, iron and arsenic. These contaminants with the exception of arsenic were reduced to acceptable levels of the South African National Standard of drinking water (SANS 241, 2004). Compared to the other filters, the BSFZ performed better in removing nitrates, phosphates and fluorides although the overall retention efficiency was low. Total organic carbon was removed greatly by the CCF (39%) and the least removal was by the BF. The overall performance of the filters in reducing contaminants from drinking water was in the order BSFZ > BSF > SIPP > CCF > BF. Filter washing vi resulted in an overall increase in the flow rates of the filters but negatively affected turbidity reduction. The filters still removed contaminants after total cumulative volumes of 1200 L (BSFZ, BSF, CCF and BF) and 300 L (SIPP) were filtered through the devices. The five evaluated filters have several advantages to the readily available technologies and the advantages include ease of construction, operation and maintenance. The filters are gravity driven and work independent of temperature. These HWTS incorporate safe storages fitted with spigots to eliminate recontamination of water when it is drawn for use. The filters can produce enough drinking and cooking water for a family of six members due to their high flow rates. The BSFZ, BSF, SIPP, CCF and BF may therefore be considered for treating contaminated water at household scale in places where water is taken directly from the source without treatment.
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DEVELOPMENT AND COMPARISON OF LINEAR AND NONLINEAR MULTIPLE REGRESSION MODELS FOR PREDICTING TRIHALOMETHANE FORMATION KINETICS.Chowdhury, Zaid Kabir. January 1984 (has links)
No description available.
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Quality of drinking water sources in the Bloemfontein area of the Mangaung Metropolitan MunicipalityRatikane, Mosepeli January 2013 (has links)
Thesis (M. Tech. (Environmental Health)) -- Central University of technology, Free State, 2013 / Introduction: Drinking water of poor quality can cause a variety of diseases and may even result in death. The impact of poor drinking water is a course for concern even in South Africa. Therefore, the physical, chemical and microbiological drinking water quality was investigated in the peri-urban area of Bainsvlei and the Woodlands Hills Estate in Bloemfontein, Free State.
Materials and Methods: The water quality was assessed in 20 identified sampling sites for three series with ten weeks apart. These sites use treated municipal and untreated borehole water for drinking. The determinants analysed for were pH, electrical conductivity (EC), turbidity, temperature, Ca, Mg, Na, F, Cl, N, SO₄,N, Free chlorine, Al, As, CN, Fe, Mn, Pb, Hg, total coliforms and E. coli. The water samples were collected and analysed on site and in the laboratory. Both the physical and chemical determinants were measured using standard methods whereas the microbiological determinants were measured using the Defined Substrate Technology (DST) method. The measurements were first compared to the SANS 241 (2011) for compliance. The ANOVA tests were used to investigate if any seasonal variations existed in the water quality as well as to compare the levels of the determinants between borehole and municipal water. In the assessment of the overall drinking water quality of different water sampling sites the water quality index (WQI) was used.
Results and Discussions: Significant effects were believed to exist if the p-values of the ANOVA and Scheffe tests were at a significance level of 5% (p < 0.05). The study results revealed that of the four physical determinants that were measured turbidity exceeded the standard in many sampling sites in the three series. Of all the chemical determinants, nitrates exceeded the standard. In the same way coliforms exceeded the standard in a number of sampling sites while E. coli was found in a few sampling sites in the first series. ANOVA tests revealed that seasonal variations existed between pH, EC, temperature, cyanide and iron at a significant level of 5% (p < 0.05) while the Post-hoc Scheffe test further revealed the series in which the effect existed. Similarly, the ANOVA tests revealed that the levels of the determinants between municipal versus borehole varied in pH, EC, Ca, Mg, Na, F, Cl, N, and SO₄ at a significant level of 5% (p < 0.05). The WQI showed that in all the series when combining the good and excellent category season 2 had the highest percentage of 80%, followed by season 3 with 79% and season 1 with 70%. Only borehole sampling sites were found in the poor, very poor and unsuitable categories. Similarly all the highest WQI values were found in borehole sampling sites.
Conclusion: This study revealed that the water quality is of good quality in the Bainsvlei and Woodlands Hills Estate of the Mangaung metropolitan municipality in Bloemfontein, in the Free State, South Africa. The presence of E. coli, though found in a few sampling sites and the high levels of turbidity, nitrates and coliforms are of concern to public health.
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COMPETITIVE ADSORPTION OF VOLATILE ORGANIC COMPOUNDS ONTO NATURAL AND SYNTHETIC ADSORBENTS (TRICHLOROETHYLENE, 1,4-DICHLOROBENZENE, TETRACHLOROETHYLENE, CARBON TETRACHLORIDE, PREDICTIVE MODELS).Odem, Wilbert Irwin. January 1985 (has links)
No description available.
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Arizona Wells: Low Yielding Domestic Water WellsUhlman, Kristine, Artiola, Janick 01 1900 (has links)
3 pp. / Arizona Well Owner's Guide to Water Supply / To develop a ground water resource, it is necessary to design and construct a well capable of yielding a pumping rate compatible with the needs of the water well owner. Sufficient and sustained well yields are highly dependent on the characteristics of the aquifer, the construction of the well, and the maintenance of the well. Causes of low-yielding wells are explained and practices to restore well performance are recommended.
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Arsenic in Drinking WaterSchalau, Jeff 10 1900 (has links)
2 pp. / Arsenic is the twentieth most abundant element in the earth's crust and frequently occurs in rock formations of the Southwestern United States. Arsenic remains in the environment over long periods and when it occurs in high concentrations, it can be toxic to many life forms, but it also has been shown to be an essential nutrient for many animal species and may be to humans, too. This publication provides information about the impact arsenic in drinking water has over human and plant health and the ways to remove it.
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Private Water Well ComponentsFarrell-Poe, Kitt, Jones-McLean, Lisa, McLean, Scott 04 1900 (has links)
4 pp. / 1. Drinking Water Wells; 2. Private Water Well Components; 3. Do Deeper Wells Mean Better Water; 4. Maintaining Your Private Well Water System; 5. Private Well Protection; 6. Well Water Testing and Understanding the Results; 7. Obtaining a Water Sample for Bacterial Analysis; 8. Microorganisms in Private Water Wells; 9. Lead in Private Water Wells; 10. Nitrate in Private Water Wells; 11.Arsenic in Private Water Wells; 12. Matching Drinking Water Quality Problems to Treatment Methods; 13. Commonly Available Home Water Treatment Systems; 14. Hard Water: To Soften or Not to Soften; 15. Shock Chlorination of Private Water Wells / This fact sheet is one in a series of fifteen for private water well owners. The one- to four-page fact sheets will be assembled into a two-pocket folder entitled Private Well Owners Guide. The titles will also be a part of the Changing Rural Landscapes project whose goal is to educate exurban, small acreage residents. The authors have made every effort to align the fact sheets with the proposed Arizona Cooperative Extension booklet An Arizona Well Owners Guide to Water Sources, Quality, Sources, Testing, Treatment, and Well Maintenance by Artiola and Uhlman. The private well owner project was funded by both the University of Arizonas Water Sustainability Program-Technology and Research Initiative Fund and the USDA-CSREES Region 9 Water Quality Program.
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Do Deeper Wells Mean Better Water?Farrell-Poe, Kitt, Pater, Susan 02 1900 (has links)
6 pp. / 1. Drinking Water Wells; 2. Private Water Well Components; 3. Do Deeper Wells Mean Better Water; 4. Maintaining Your Private Well Water System; 5. Private Well Protection; 6. Well Water Testing and Understanding the Results; 7. Obtaining a Water Sample for Bacterial Analysis; 8. Microorganisms in Private Water Wells; 9. Lead in Private Water Wells; 10. Nitrate in Private Water Wells; 11.Arsenic in Private Water Wells; 12. Matching Drinking Water Quality Problems to Treatment Methods; 13. Commonly Available Home Water Treatment Systems; 14. Hard Water: To Soften or Not to Soften; 15. Shock Chlorination of Private Water Wells / This fact sheet is one in a series of fifteen for private water well owners. The one- to four-page fact sheets will be assembled into a two-pocket folder entitled Private Well Owners Guide. The titles will also be a part of the Changing Rural Landscapes project whose goal is to educate exurban, small acreage residents. The authors have made every effort to align the fact sheets with the proposed Arizona Cooperative Extension booklet An Arizona Well Owners Guide to Water Sources, Quality, Sources, Testing, Treatment, and Well Maintenance by Artiola and Uhlman. The private well owner project was funded by both the University of Arizonas Water Sustainability Program-Technology and Research Initiative Fund and the USDA-CSREES Region 9 Water Quality Program.
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