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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.
31

A chemical and physical profile of White River-1975

Posavec, Steven J. January 1976 (has links)
When sampling natural waters for constituent analyses, it is essential that a representative sample be obtained. This sampling survey was undertaken to study the effect of sampling depth on analyses as well as obtain useful data from the White River.Samples at three depths were collected at one location on the White River during two five-week periods. These samples were analyzed for the following constituents: total alkalinity, chloride, apparent color, calcium hardness, magnesium hardness, total hardness, tonal iron, ammonia nitrogen, nitrate nitrogen, dissolved oxygen, orthophosphorus, total inorganic phosphorus, total phosphorus, specific conductance, sulfate, and turbidity.The results indicated that sample depth is not a factor in the majority of the analyses described. For certain constituents, such as chloride and ammonia, however, sample depth is a factor to be considered. This survey also provided additional data on White River water quality and indicated that precipitation affected constituent concentrations.
32

Biofilm Detection through the use of Factor Analysis and Principal Component Analysis

Unknown Date (has links)
Safe drinking water is paramount to a healthy society. Close to a hundred contaminants are regulated by the government. Utilities are using chloramines to disinfect water to reduce harmful byproducts that may present themselves with the use of chlorine alone. Using chlorine and ammonia to disinfect, ammonia oxidizing bacteria can present themselves in an unsuspecting utilities distribution network. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
33

Impacts of mining and mine closure on water quality and the nature of the shallow aquifier, Yandi Iron Ore Mine

Gardiner, Sean Jonathan January 2003 (has links)
The Hamersley Yandi Iron Ore Mine of Hamersley Iron Pty. Ltd. is located in the Pilbara region, Western Australia, approximately 90km north west of the town of Newman. The iron ore has accumulated in a palaeochannel as an enriched Channel Iron Deposit (CID). Mining in other parts of this palaeochannel has been practised since 1991. Named deposits in the province are, from west to east, Munjina, Pool, Meander, Western, Central, Eastern, Junction and the Billiard deposits.Presently the CID acts as an aquifer and transmits water through its fracture system. It is the main conduit for the regional groundwater. The Water and Rivers Commission of Western Australia considers the groundwater in the alluvial beds of the Weeli Wolli Creek overlying the CID to be a useful resource. The groundwater is currently used for stock watering so the quality should be preserved.Part of the four possible closure plans of the Yandi Mine is to backfill the excavated channel with waste rock from the mining operation. The waste material will consist of the uneconomic grade lateritic pisolite iron ore, together with colluvium and alluvium overburden. The closure plans will also leave behind two pit lakes.The impact of these closure plans vary but each plan will leave pit lakes containing water with high salinity and this may adversely affect the quality of the groundwater downstream of the lakes.The hydraulic conductivity of the shallow aquifer may be impaired by swelling clays found in parts of the waste material. This impact would be reduced if the chosen closure plan was one with hydrogeological flow management.The water quality downstream of the pit lakes will change and the environmental impact on the groundwater will depend on which closure plan is chosen. This thesis suggests a number of options for consideration.
34

Characterisation of organic and inorganic components in process water from a novel lignite dewatering process

Qi, Ying, 1964- January 2004 (has links)
Abstract not available
35

Applied use of radioimmunoassay for detection of viral hepatitis in water samples

Carter, Judy K. 03 June 2011 (has links)
Viral hepatitis is a disease caused by a virus, or a virus-like particle and is extremely infectious. Infection can occur when the virus is present in minute quanities. Outbreaks of this disease have been associated with water supplies contaminated with raw sewage. Detection of viral hepatitis in water samples, at present, consists of testing the serum of persons who have contracted the disease after consuming water suspected of containing hepatitis virus. Since this method of determination is time consuming and subjective, an alternative method of detecting the presence of hepatitis virus in water was explored in this research.Radioim munoassay (RIA), used for the detection of Australia antigen (HAA) in the serum of humans, utilizes a tagging system in which Australia antigen antibody is bound with iodine-125. This technique, a combination of chemistry and immunology, can detect less than one- billionth of a gram of HAA in serum and requires approximately four hours to complete the testing. RIA detection of HAA is presently limited to detection of HAA in serum samples.This research used RIA as a detection system to test water samples collected from local water sources. Control serum samples collected from a local hospital were tested for HAA. Fifteen water samples and two serum samples tested were positive upon initial testing for Australia antigen. HAA was also detected in water samples in control situations in which sera with a high titer to HAA were diluted in water and then tested using RIA.Ball State UniversityMuncie, IN 47306
36

Relationship between interfacial properties and formation of microemulsions and emulsions of water and supercritical carbon dioxide

Psathas, Petros 31 March 2011 (has links)
Not available / text
37

Sedimentation and chemical processes on the Lower Mkuze floodplain : implications for wetland structure and function

January 2008 (has links)
The Mkuze Wetland System, situated in northern KwaZulu-Natal, is South Africa’s largest freshwater wetland area. The system plays a vital role in the functioning of the local landscape and has been identified as an important site for the retention of a number of solutes. The mechanisms through which this retention occurs were investigated through analysis of sediment, groundwater and porewater samples collected from the lower floodplain. Sample analysis was achieved through the use of several techniques, including Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), X-ray Diffraction (XRD), X-ray Fluorescence (XRF), electron microscopy and sequential extraction. / Thesis (Ph.D)-University of KwaZulu-Natal, Westville, 2008.
38

Removal of reactive dyes from dye liquor using activated carbon for the reuse of water, salt and energy.

Mbolekwa, Z. January 2007 (has links)
The removal of colour from effluent after dyeing of cellulosic fibres is a major problem due to the difficulty in treating such effluents by conventional treatment methods. Cellulosic fibres of a specific shade (colour) are produced by reacting the fibres with a mixture of reactive dyestuffs, salt and auxiliary chemicals. Reactive dye exhaustion to the fibre is about 80% i.e. 20% remains in the effluent; this is hydrolysed dye which cannot be reused for dyeing. The exhausted reactive dye bath together with first rinse represents 6 to 30 L effluent/kg of fabric and most of the colour and salt. The total water consumption for reactive dyeing ranges from 25 to 100 L effluent/kg fabric while the water consumption from total textile finishing ranges from 30 to 150 L effluent/kg fabric. Thus the concentration of the dye and salts are 5 times more concentrated when obtained at source. The use of activated carbon adsorption for the removal of colour from exhausted dyebath for the re-use of water, salt and energy has been studied. Four different commercial reactive dye chemistries and associated auxiliaries were tested and commercial activated carbon was used as an adsorbent. Different temperatures (20°C to 100°C), pH values (acidic, neutral, basic) and salt concentrations (50 g/L to 100 g/L) were evaluated and the high adsorption results were achieved when using high temperature, low pH (acidic) and high salt concentrations. The Freundlich adsorption parameters were obtained for activated carbon adsorption capacity and adsorption bond strength between reactive dyes and activated carbon. The overall removal of the reactive dye shades was 36% to 53% (based on colour in the effluent), salt recovery was about 94% to 97%, the water recovery ranged from 14% to 25% and energy savings of 17% to 32% could be achieved. Column adsorption test were performed at different temperatures and flowrates. The saturated activated carbon was regenerated and repeatedly used by elution with 1.0 M NaOH. The regenerated carbon was found to be effective up to 3 cycles of operations. A column system for treatment of reactive dyes using activated carbon was designed. The outcome of this study showed that treatment of reactive dyebath with activated carbon adsorption technique can allow re-use of water, salt and energy, thus enabling environmental improvements with a savings in salt, energy, water and treatment costs. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2007.
39

The health-related microbial quality of drinking water from ground tanks, standpipes and community tankers at source and point-of-use in eThekwini Municipality : implications of storage containers, household demographics, socio-economic issues, hygiene and sanitation practices on drinking water quality and health.

Singh, Urisha. January 2009 (has links)
The aim of this study was to investigate the microbiological quality of drinking water at the source (taps at eThekwini laboratories, standpipes and mobile community tankers) and corresponding point-of-use (storage containers and ground tanks) supplied to peri-urban areas in Durban by eThekwini Municipality. It also aimed to identify factors associated with deterioration in water quality such as storage of water, household demographics, hygiene and sanitation practices. In order to determine the microbial quality of drinking water, the pour plate method (for enumeration of heterotrophic organisms) and the membrane filtration technique (for total coliforms and E. coli enumeration) were used. Conductivity, turbidity, pH and total and residual chlorine levels of drinking water were measured. Microbial and physico-chemical data was collated and statistically analysed with epidemiological data from an associated study to determine the link between microbial quality of drinking water, household demographics, health outcomes, socio-economic status, hygiene and sanitation practices. Findings showed that all point-of-use water was unsafe for human consumption as a result of either poor source water quality, in the case of standpipes, and microbial contamination at the point-of-use, in the case of ground tanks and community tankers. The latter could be attributed to unsanitary environments, poor hygiene practices or poor wateruse behaviour. Households which included children aged 0-5 years and in which open-top containers were used for water storage had the highest rates of diarrhoea and vomiting. Water from ground tanks had the best microbial quality but people in households using this water presented with the highest rate of diarrhoea. Therefore provision of microbially safe drinking water will not reduce the rate of health outcomes if addressed in isolation. In order to reduce water-associated illness, provision of safe and adequate amounts of water, hygiene and sanitation education and education on water-use behaviour should be provided as a package. The provision of improved water delivery systems does not ensure that drinking water is safe for human consumption. Measures, such as point-of-use water treatment should be considered to ensure that drinking water provided at the source and point-of-use is microbially safe for human consumption. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.
40

Determination of nitosoamines by DP polarography and investigation of kinetics of electroreduction of N-Nitrosodimethylamine by voltammetric techniques / Mbhuti Hlophe

Hlophe, Mbhuti January 2005 (has links)
This study has two aspects. One concerns the development of a sensitive differential pulse polarographic (DPP) method and its use to conduct a preliminary study of natural waters to detect the presence of nitrosoamines, and the second, where the study was carried out in greater detail, is the investigation of the kinetics of reduction of N-nitrosodimethylamine (NDMA) in aqueous solution. An optimization study was first conducted to identify the conditions that give the greatest sensitivity. Conditions investigated were different supporting electrolytes and solvent mixtures. Supporting electrolytes used were 0.10 M solutions of acids, bases and salts, and the solvent mixtures studied were ethanol/water mixtures. The effect of various supporting electrolytes and various ethanol/water mixtures on peak current was studied in order to select the conditions that give the greatest sensitivity for the determination of nitrosoamine concentrations. The lowest nitrosoamine concentration that can be detected in a solution (limit of detection) was determined. The optimum supporting electrolytes for N-nitrosoamines and the C-nitrosoamine were respectively found to be 0.10 M H2S04 and 0.10 M NaOH. Aqueous solutions were also found to give greater sensitivity than ethanol/water mixtures. The presence of nitrosoamines in some natural water samples was then checked using differential pulse polarography (DPP).Concentrations of nitrosoamines in these water samples were determined using the optimum conditions. The analyte analytes studied were 4-nitroso-N,N-dimethylaniline (4NDMA); Nnitrosodibutylamine (NDBA),N-nitrosodi-n-propylamine (NDPA) and N-nitrosodiphenylamine (NDPhA). All four nitrosoamines were detected in some of the selected natural water samples . The kinetics of the electrochemical reduction of NDMA was studied using controlled potential coulometry, linear scan voltammetry (LSV) and cyclic voltammetry (CV). Controlled potential coulometry was first used to determine the number of electrons transferred (n) in the reduction reaction. Two moles of electrons were found to be required for the reduction of one mole of NDMA solution, at a stationary mercury drop electrode (SMDE). The major product obtained, identified by UVNIS spectroscopy, was dimethylamine (DMA). / Ph.D. (Chemistry) North-West University, Mafikeng Campus, 2005

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