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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.
281

Water Quality Assessment of Karst Spring Water as a Private Water Supply Source in Northeast Tennessee

Fashina, Lukman 01 May 2022 (has links)
Karst springs are an essential source of private water supply for about 10% of households in Tennessee. However, these springs, which can be easily polluted, are unregulated. This study, therefore, assesses water quality spatial patterns and water quality rating of roadside springs in northeast Tennessee. Karst spring water samples collected from 50 springs were assessed using EPA Standard methods for pathogens, nutrients, radon, and physicochemical parameters. Springs generally met federal and state standards for physicochemical parameters, 90% of samples contained E. coli, and all samples contained fecal coliform. High E. coli was spatially clustered causing a fecal contamination hot spot on the border of Washington and Sullivan Counties, Tennessee. 60% of springs exceeded radon concentrations of 300 pCi/L. Water quality ratings were very poor or unfit for drinking, with 4% of springs ranked “good”. Therefore, microbial pollution purification procedures are advised before using these springs as a drinking water source.
282

Fish, water and sediment quality as indicators of land-use change in the Steelpoort River (Olifants River System, Limpopo Province)

Makushu, Elelwani Tabitha January 2018 (has links)
Thesis (M.Sc. (Zoology)) -- University of Limpopo, 2018 / This study aimed to determine the effects of water and sediment quality on fish and the effects of land-use on the water and sediment quality of the Steelpoort River system. To achieve these aims, a few objectives had to be met. The water and sediment quality, the level of metal bioaccumulation of two fish species, the level of acetylcholine esterase inhibition in fish brain tissue, as well as changes in land-use over time. The study adds value in the scientific knowledge of the Steelpoort catchment given that there’s little information about it. It is thus a good baseline, which gives direction for further studies conducted within this catchment. The Steelpoort River, is a tributary of the Olifants River system. The Olifants River (Mpumalanga and Limpopo provinces) is a river stressed by anthropogenic activities with the Steelpoort River being a major sub-catchment. The Steelpoort catchment is filled with mines, agricultural activities, and other developments, such as, the construction of a new dam (De Hoop Dam opened 2014), residential areas and malls. The mines within the catchment are mostly platinum and chrome mines. Sampling was conducted for high and low flow at five sampling sites: Two upstream sites, 1 and 2, and three downstream sites 3, 4, and 5. Site 1 is the reference site for the study as this section (ecoregion) was described as “least threatened”. It was hypothesised that high concentrations of metals and nutrients would be present in the water and sediment, and that the metal would be present in fish tissue and would have an effect on human health, that the biomarker AChE would show signs of inhibition within brain tissue, and lastly that land-use characteristics would have an effect on the water and sediment quality, and inhibition of AChE. Water and sediment samples were collected quarterly over a period of a year at five sites, whereas fish samples (Chiloglanis pretoriae and Labeobarbus marequensis) were only collected bi-annually at three sites. The physico-chemical, nutrients, cations and ions, and metals and metalloids were determined. The two fish species were used for metal bioaccumulation and AChE analyses. Human health risk and bio-concentration factor (BCF) analyses were conducted. Using the land-cover details obtained from South African National Biodiversity Institute (SANBI), Department of Environmental Affairs (DEA) and The Council for Scientific and Industrial Research (CSIR), land-use characteristics were determined and evaluated. The in-situ physico-chemical parameters assessed in this study were found to be within acceptable limits of the Target Water Quality Range (TWQR) at all the sites. The Electrical Confuctivity (EC) and Total Disolved Solids (TDS) parameters were highest at Site 5 and lowest at Site 1, this could be due to Site 5 being the last site before the Steelpoort River connects to the Olifants River, hence this site recieves all the ions and solutes from upstream; and the lowest value at Site 1 could be attributed to this site having the least number of lan-use effects. For nutrients, the highest total nitrogen concentration was recorded at Site 5 and the highest phosphate concentration at Site. This river is mesotrophic according to both the total inorganic nitrogen and phosphorus levels. Metals in the water column that were above DWAF guidelines for Aquatic Ecosystems were Al, Ba, Mn and Zn. In the sediment the following metals were above the Canadian sediment quality guidelines: Cd, Cu, Cr and Zn, which can pose a threat to the health of fish through biomagnification through the food chain. Both C. pretoriae and L. marequensis had bioaccumulated metals from the river system. The concentrations of metals in the muscle tissue of C. pretoriae where higher and this could be due to the fact that unskinned samples were used in the case of C. pretoriae. A variety of metals were present in both fish species but Al, Fe, Sr and Zn were present in higher concentrations. Concentrations of metals were highest in samples from Site 5 The human health risk assessment revealed that Pb could cause health related impacts to the humans who consume a single 150 g fish meal once a week in C. pretoriae; and that Co could cause potential risks in the near future. The BCF values revealed that there were more bioconcentrated metals in C. pretoriae than in L. marequensis and this could also be due to different diets. The AChE activity was higher for L. marequensis during high flow at all sites and higher at Site 1 during low flow but lower at Site 5 and equivalent at Site 2 than the AChE activity recorded for C. pretoriae. This could be due to the ability of L. marequensis to expel pesticides from their system before the pesticides affect brain activity by decreasing the function of AChE. Both fish species had more AChE activity during low flow for sites 1 and 2 than during high flow. The high flow AChE activity was higher for Site 5 in both fish species. The results confirm the hypotheses were that metals would be present in fish tissue and would have an effect on human health; and that the biomarker AChE would show signs of inhibition within brain tissue. The agricultural activity has decreased over time within the catchment, from 2000 to 2014 and this could be due to a decrease of fertile land. There has also been a decrease in the mining activity from 2000 to 2009 and then an increase during 2014, where the decrease could be due to the closure of mines at the end of their life span; and the increase in 2014 could be due to the opening of new mines. Residential areas have increased from 2000 through to 2014. The availability of water decreased from 2000 to 2009, and then increased drastically in 2014. The drastic increase is due to the multiple dams that have been built over time in order to provide water resources to the increased population, and also for mining and irrigation purposes. The water quality showed an increase in the NO3, SO4 and PO4; meanwhile the EC has decreased over time. The decrease in EC means that there are fewer ions in the river. The increase in phosphates and nitrates could mean there is a lot of fertilizers and pesticides being used in agriculture even with the decrease in agricultural land-use over the years. The pesticides can also be due to the increase in residential areas, where pesticides are also used to get rid of pests.
283

Water quality factors affecting the restoration of the Rio Grande

Peinado Coronado, Porfirio, January 2007 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
284

A comparative policy analysis on Washington and Oregon management policies for zebra mussel infestations within the Columbia River Basin

Cantin, Jesse Joseph Rutherford. January 1900 (has links) (PDF)
Thesis (M.E.S.)--Evergreen State College, 2009. / "June, 2009." Title from title screen (viewed 4/8/2010). Includes bibliographical references (leaves 48-54).
285

A physical and chemical characterization of stream water draining three Oregon Coast Range catchments /

Hale, V. Cody. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.
286

A Water Quality Study of Lake Texoma

Goodman, John Willis 06 1900 (has links)
A series of four stations for sampling the waters of the Red Rivers and Lake Texoma was established. Water samples from top, middle, and bottom levels of these four stations were taken on monthly intervals during periods of homothermousity and on two-week intervals during periods of thermal stratification. These samples were analysed for the cations sodium, potassium, calcium, and magnesium, and for the anions normal carbonate, bicarbonate, sulfate, chloride, nitrate, water hardness (expressed as calcium carbonate), and phosphates. Determinations for dissolved oxygen, carbon dioxide, pH, temperature, and specific conductance were performed. Using these data, vertical profiles of the lake at these four stations were established. From the study of these data it was concluded that the waters of the Red River improve in quality coincident with impoundment, and that these improvements are sufficient to warrant the use of these waters.
287

Fish and benthos communities in regenerated dock systems on Merseyside

Fielding, Nicola Jane January 1997 (has links)
Restored docks have high amenity, tourism and recreational value. Polluted and unaestheticw ater is a major factor potentially inhibiting redevelopmento f docklands, particularly if the source of water suffers from severe pollution problems. The aims were to examine spatial and temporal patterns of hydrography and ecology of Merseyside Docks. Strategies to develop benthic filter-feeders on both the walls and in the sediments were considered important in maintaining good water quality. In the South Docks, algal blooms were mainly small and short-lived and anoxia was infrequent. In Princes Dock (Central chain) water quality was very good. Morpeth Dock (Wirral chain) suffered from poor water quality. Anoxia resulted in high mortalities of dock fauna and fish and the release of hydrogen sulphide gas. Algal blooms were very large and were maintained over long periods. The dinoflagellate, Prorocentrum minimum, was particularly prevalent. Zooplankton have remained at relatively low densities in the South Docks, particularly in Albert Dock (South chain), probably because of strong competition for food with benthic filter-feeders. In contrast, Morpeth Dock has maintained much higher numbers, probably because of the plentiful food supply and absence of benthos. The benthos of the walls was surveyed. Mytilus edulis is most prominent in Albert and Queens Docks; Ciona intestinalis and Ascidiella aspera are most abundant in Albert and Princes Docks; and, Molgula manhattensis dominant in Brunswick and QueensD ocks. Tiles have been used to follow the pattern of annual successiona nd the effect of timing of available space on this pattern of succession. In contrast to previous years when there had been very little recruitment of Mytilus to the South Docks, Mytilus settlement occurred in Queens Dock during autumn 1995. Experiments aimed at increasing the filter-feeding capacity by introducing Cerastodermae dule (common cockle) and manipulating particle size of the sediment concluded that cockles do not survive in the dock, probably due to occasional low oxygenc on centrations in the hypolimnion, and modification of sediment has very little effect on natural colonization. Experiments examined the impact of filter-feeders on phytoplankton numbers and regeneration of nutrients. Mytilus was shown to have higher clearancer ates( cell mV h' int) than its major competitors( Ciona intestinalis, Styela plicata) on the dock wall. The experiment investigating nutrient release by Mytilus indicates release of phosphate. Fish communities in the South Docks were relatively diverse, with a total of fifteen species of fish being caught. The size/frequency analyses suggest that the majority of fish were juveniles. The occurrence of two sea trout (Salmo trutta) indicates a return of salmonids to the estuary. The use of a capacity model as a management tool is proposed; this has been fitted to the South Docks system with some success.
288

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.
289

Surface water quality indicators in China and their implications for sustainability

Kwong, Pui-ki., 鄺沛琪. January 2006 (has links)
published_or_final_version / abstract / China Development Studies / Master / Master of Arts
290

Sediment supply and transmission dynamics in reservoired catchments of the Bowland Fells, Lancashire, UK

Goodwill, Paul January 1998 (has links)
No description available.

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