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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.
21

A study of artificial destratification of fresh water lakes

Ritchie, John Clarke Weldon January 1970 (has links)
The water quality characteristics of various lake classifications are discussed and are related to the natural physical and biological development of lakes. The impact of human activity on this natural trend is considered. The results of an extensive literature search are presented, discussing seasonal variations in water quality in fresh water lakes. Methods of altering water quality are outlined, with particular emphasis on the artificial elimination of summer thermal stratification. Results of observations made of Osoyoos Lake during the summers of 1969 and 1970 are presented. Tests of an aeration installation in the lake are reported and discussed. Laboratory investigations into the mechanisms of destratification are described. Simulation of thermal stratification was achieved through the use of a fresh water-salt water system. Three destratification devices were tested under various stratification conditions and their energy requirements are compared. Discussion of the results includes some comments on the reliability of stability and energy criteria for the evaluation of such devices. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
22

Toward an information framework for water quality planning : The Fraser River main stem case study

Nickel, Jack Michael January 1980 (has links)
This study examines the existing practice and legislative base for water quality management at both federal and provincial levels in British Columbia and shows that the movement toward preventative-management presently underway will lead to increasing demands for systems oriented data and methods of interpreting this data for planning purposes. An information framework is developed for stream-quality assessment of flowing surface waters based on a one-dimensional representation of the water system, a finite segment approach to data organization, and a combination dilution model/ materials balance approach to system simulation and analysis. The approach is designed to use available data and the framework is computerized. The analysis framework is applied to the main stem of the Fraser River above Hope. Although a large amount of data has been collected in this watershed, diverse agency objectives and lack of co-ordination in data collection programs limits the analysis to ten river segments and nine water quality parameters; flow, pH, temperature, specific conductance, dissolved sodium, suspended solids, total iron, total managanese, and total copper. Using the best data presently available, data gaps, in-stream behavior, assimilative capacity estimates based on standards and quality changes induced by development are discussed for several of these parameters as an illustration of the framework's use as a research and planning tool. Water quality data collected during 1976 for regulatory and system surveillance purposes were assembled and used to simulate the behavior of conservative materials or to quantify the observed deviation from conservative behavior. These deviations identify and assist analysis of the aggregate quality influences of non-specific source inputs and/or in-stream transformation processes. They also allow limited prediction of the water quality changes associated with water and related resource developments. The study shows that very little data has been collected in the upper reaches of the Fraser main stem, that unaccounted dilution can have as great an effect on water quality as accounted material inputs, that grab samples are not adequate representations of mean monthly quality, that quality degradation from industrial discharge below Prince George is largely offset "by the dilution influence of the Nechako River, and that a scouring followed by downstream deposition phenomenon can he observed through a materials balance analysis. Also, it is shown that new waste loads and dams can have a significant effect on quality. It is recommended that the approach developed here be adopted as an aid to water quality management, surveillance network design and data interpretation. A joint federal/provincial committee should be established under the Canada Water Act to co-ordinate management effort. The provincial government should establish a water resource planning component in the Environment and Land Use Committee Secretariat' to develop planning procedures and integrate these procedures with land use planning. A pilot water resource management study should begin in each resource management region of the province. Future work should concentrate on the development of water quality standards and mechanisms of public input to water resource planning studies. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
23

Professional development for water quality control personnel /

Shepard, Clinton Lewis January 1980 (has links)
No description available.
24

Design of water quality monitoring systems in Latin America /

Drobny, N. L. January 1971 (has links)
No description available.
25

A Computer Model to Determine Location of Stormwater Management Practices

Zahm, Alan D. 01 January 1982 (has links) (PDF)
To optimize the placement of stormwater management systems, a Radio Shack BASIC computer program "SELECT" was written. The program selects locations for berms, detention ponds, retention ponds, and underground percolation tanks based upon minimum marginal cost (totally present value cost per pound of nutrient removed annually). Either nitrogen or phosphorus can be chosen as the selected nutrient. The selections occur until the desired percentage removal is obtained. Five output tables show the results of the selection process. The computer model was used to evaluate stormwater management locations for the Lake Tohopekaliga watershed in Florida. Input data consisting of soil types, land costs, and construction costs were obtained. "SELECT" was run to determine stormwater management locations for different nitrogen and phosphorus percentage removals. Sensitivity analyses upon land costs, nutrient loading, and removal efficiencies for the 45 percent removal cases of nitrogen and phosphorus were evaluated.
26

Transboundary water pollution between Hong Kong and the Pearl River Delta Region : Dongjiang River as a case study /

Cheung, Sheung-ching. January 2002 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 152-155).
27

An analysis of water quality policy and management in China an examination of water planning at the national and local level /

Shao, Wanyun. January 2009 (has links)
Thesis (M.P.)--University of Wyoming, 2009. / Title from PDF title page (viewed on June 10, 2010). Includes bibliographical references (p. 102-107).
28

Water quality management at Halfway on the Sishen-Saldanha rail

Van der Schyff, Karlien 10 February 2014 (has links)
M.Sc. (Geography) / Please refer to full text to view abstract
29

Paint wastewater treatment using Fe3+ and Al3+ salts

Ntwampe, Irvin Oupa Lesele 10 September 2014 (has links)
A PhD thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering. Johannesburg / This study involves the investigation of the paint wastewater treatment using inorganic coagulants such as FeCl3, Fe2(SO4)3, AlCl3 and Al2(SO4)3 in a jar test during rapid and slow mixing for 250 and 100 rpm respectively, settled the samples, measure the pH and turbidity. The pH, turbidity and area covered by the flocs were used as measurements in this study to determine the quality of treated paint wastewater. In the first experiment, 200 mL sample of 169.2 g of paint wastewater dissolved in 1L of potable water was poured into six 500 mL glass beakers sample dosed with FeCl3 only, combined FeCl3 and Ca(OH)2 or Mg(OH)2 as well as FeCl3-Ca(OH)2 and FeCl3-Mg(OH)2 polymers respectively, run through a jar test with rapid and slow mixing. The supernatant was extracted after 1 hour settling to measure the pH and turbidity. The observations showed that combined FeCl3 and Mg(OH)2 as well as FeCl3-Mg(OH)2 polymers yielded identical and slightly higher turbidity removal than combined FeCl3 and Ca(OH)2 and FeCl3-Ca(OH)2 polymers. Another batch of experiments was carried out using the same metal salts with Ca(OH)2 and Mg(OH)2 respectively for pH adjustment. The samples were treated in a jar test using various dosing patterns such as dosages, dosing prior or during mixing, combined dosages interchangeably, retention time. A third batch of experiments was carried out by dosing synthetic polymers of FeCl2-Ca(OH)2 and FeCl2-Mg(OH)2 respectively using similar dosing patterns. The results obtained in first set of experiments, were Fe3+ and Al3+ salts were added in paint wastewater showed that the changing pH correlates with turbidity removal. It was also observed that dosing prior or during mixing do not play any significant role in wastewater treatment. Another observation showed that flocculation of the paint wastewater dosed with FeCl2-Ca(OH)2 or FeCl2-Mg(OH)2 polymers do not show correlation between the pH and turbidity, which indicates that the pH is not an indicator of turbidity removal in a more alkaline solutions such as paint wastewater. A second study was carried out using the same paint wastewater samples (200 mL) and samples dosed with Fe3+ and Al3+ salts treated in a jar test and immediately two drops of supernatant were placed on a microscope slide and view it under a microscope connected to a camera, images were captured after 1, 60 and 90 minutes respectively (Exp A). Samples were prepared from the original paint wastewater and the standard solution of Fe3+ and Al3+ in a small scale using identical metal salt/paint wastewater volume ratios as above. Two drops from the paint wastewater and metal salt solution were place on a microscope slide and images were captured as above using 1, 60 and 90 minutes respectively (Exp B). All the visuals were printed and the visuals obtained in Exp A were compared with their corresponding visuals in Exp B in accordance with time. The results obtained showed that the percentage area covered by flocs treated in a jar test (Exp A) correlates linearly with the percentage area covered by the flocs from a microscope slide (Exp B). The results obtained using this technique also confirm that the reaction between the drops of a sample and the drops of coagulant produces well-developed solid hydrolysis species. A third study was carried out by pouring 200 mL of the same paint wastewater samples into six 500 mL glass beakers and with Fe3+ and Al3+ salts as above, run through a jar test during 30, 45 and 60 seconds rapid mixing (250 rpm) only for 2 minutes respectively. The samples settled for 1 hour, and then pH and turbidity were measured. Another experiment was carried out using the similar method as above with samples run through a jar test at 250 rpm during 30, 45 and 60 seconds rapid mixing (250 rpm) for 2 minutes followed by slow mixing (100 rpm) for 10 minutes (combined rapid and slow mixing). The samples settled for 1 hour, and then pH and turbidity were measured. The results obtained from the jar tests (comparison between flocculation during rapid mixing only and combined rapid and slow mixing) showed that the pH in the samples with rapid mixing shows an insignificant change compared to their corresponding samples with combined rapid and slow mixing; turbidity in the samples with 30, 45 and 60 seconds rapid mixing showed that most of the flocs are formed within 30 seconds. There is a correlation between the pH and turbidity when paint wastewater is dosed with Fe3+ or Al3+ metal ions in their respective metal salts without pH adjustment. The Fe3+ and Al3+ of the same concentration yield a similar pH and turbidity trend.
30

Analysis and interpretation of stochastic water quality data using parameter estimation and spectral analysis techniques

Lizcano Jauregui, Juan Jose January 2010 (has links)
Digitized by Kansas Correctional Industries

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