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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.
391

Group invariant solutions for contaminant transport in saturated soils under radial uniform water flow background

Potsane, Moshe Moses 06 August 2013 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in ful llment of the requirements for the degree of Master of Science. March 27, 2013 / The transport of chemicals through soils to the groundwater or precipitation at the soils surfaces leads to degradation of the resources such as soil fertility, drinking water and so on. Serious consequences may be su ered in the long run. In this dissertation, we consider macroscopic deterministic models de- scribing contaminant transport in saturated soils under uniform radial water ow backgrounds. The arising convection-dispersion equation given in terms of the stream functions is analyzed using classical Lie point symmetries. A number of exotic Lie point symmetries are admitted. Group invariant solu- tions are classi ed according to the elements of the one-dimensional optimal systems. We analyze the group invariant solutions which satisfy some physical boundary conditions. The governing equation describing movements of contaminants under ra- dial water ow background may be given in conserved form. As such, the conserved form of the governing equation may be written as a system of rst order partial di erential equation referred to as an auxiliary system, by an in- troduction of the nonlocal variable. The resulting system of equations admits a number of (local) point symmetries which induce the nonlocal symmetries for the original governing equation. We construct classes of solutions using the admitted genuine nonlocal symmetries, which include the invariant solutions obtained via corresponding point symmetries of the governing equation.
392

Biomonitoring of metal contamination in the lower Diep River, Milnerton, Western Cape

Shuping, Likentso Sylvia January 2008 (has links)
Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2008 / The lower Diep River is a major freshwater ecosystem in the Western Cape. The river is surrounded by many possible sources of metal pollution such as an oil refinery, industries, a sewage treatment plant and a landfill site. However, metal contamination levels have not been monitored in this river. The aim of the study was therefore to monitor the degree of metal pollution in the lower Diep River, over a period of one year, and to investigate the use of the sedge Bolboschoenus maritimus, as biomonitor species. Three sampling sites were used. Site I was located in the vicinity of landfill sites and farm areas. Site 2 was located I km upstream from a wetland reserve, surrounded by heavy industrial activity and continuous residential developments. Site 3 was located downstream of the wetland reserve, 2 km from the river mouth. The following metals were investigated: aluminium, cadmium, chromium, cobalt, copper, iron, lead, manganese, nickel and zinc. Water and sediment samples were collected every two months for a period of one year. Plant specimens (roots, leaves and stems) were collected seasonally from site I and site 3. Samples were acid digested and metal analysis was done using an ICP - AES (Inductively Coupled Plasma- Atomic Emission Spectrophotometer). Statistical analyses were done to investigate possible differences between the sites, sampling occasions and various plant components.
393

Microbial pollutants in stagnant water in RR section, Khayelitsha, Western Cape, South Africa

Leuta, Qenehelo Alice January 2015 (has links)
Dissertation submitted in partial fulfilment of the requirements for the degree Master of Technology: Environmental Management in the Faculty of Applied Science at the Cape Peninsula University of Technology / Greywater is domestic wastewater from daily kitchen, laundry, bath, shower, hand washing practices and does not include wastewater from the toilet. Greywater from informal settlement has been identified as important environmental pollution sources. Inadequate sanitation and poor drainage in informal settlements result in greywater being stagnant at the base of communal taps. This water has a potential to cause health problems to those who come in contact with it. Studies of greywater quality in informal settlements in South Africa tend to concentrate on physico-chemical analysis and microbial indicator organisms. In order to adequately manage greywater in informal settlements there is a need to understand the microbial pathogens present in such water. Therefore this study is aimed at determining the level of microbial contamination of stagnant greywater in the RR Section of Khayelitsha, Western Cape. Six sampling sites were identified and sampling of stagnant greywater was conducted twice a month (from January to May 2013) from the base of six communal taps, which served as the sampling sites. The microbial enumeration techniques employed in this study were the Most Probable Number (MPN) techniques, the Heterotrophic Plate Count (HPC) technique and the Flow Cytometric (FCM) technique. The API 20E and the RapID™ ONE systems were used to identify possible pathogenic Gram-negative microorganisms, while possible pathogenic Gram-positive microorganisms were identified with the BBL Crystal™ Gram Positive (GP) Identification (ID) system. The highest MPN counts were 1.6 x 108 microorganisms/100mℓ recorded at Site A (weeks 3 and 5) as well as at Site B (week 5). The corresponding highest faecal coliform count was 4.7 x 106 microorganisms/100mℓ obtained at Site B (week 5). The highest E. coli count observed was 1.8 x 106 microorganisms/100mℓ recorded at Site A (week 5) and Site F (week 5). In comparison, the highest HPC count was 2.9 x105 microorganisms/mℓ recorded at Site C in week 4. The results obtained by the MPN and HPC techniques were significantly (p < 0.05) higher than the water quality standards by Department of Water Affairs and Forestry (DWAF) (1996a; 1996b) and the SABS (2011). The highest total FCM and viable FCM counts were 3.4 x 107 microorganisms/mℓ and 3.1 x 107 microorganisms/mℓ, respectively recorded at Site A in week 5. The FCM technique displayed significantly (p < 0.05) higher results than both the MPN and HPC techniques, which highlighted its reliability in obtaining more accurate enumeration results. The RapID™ ONE and the API 20E identification systems mostly identified Escherichia coli, Klebsiella pneumonia, K. oxytoca, Acinetobacter baumannii/calcoaceticus and Enterobacter cloacae, while the organisms more commonly identified by the BBL Crystal™ Gram Positive (GP) Identification (ID) system, were the Corynebacterium species, and Bacillus cereus. The presence of these organisms raises health concern to the community of RR Section, as some are known to cause waterborne diseases, while others are known to cause nosocomial infections.
394

Antibiotics in the Diep River and potential abatement using grape slurry waste

Chitongo, Rumbidzai January 2017 (has links)
Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2017. / Pharmaceuticals have found extensive application in human health management. They are released into the environment through urine, excreta and inappropriate disposal methods. Residues of pharmaceutical products have been reported to show toxic consequences in some freshwater and marine organisms. Antibiotics are one of the most important groups of common human pharmaceuticals widely in use as prescribed and non-prescribed drugs. Antibiotics and their metabolites have been quantitated in water and found in trace levels. But even at such low concentrations they can maintain high biological activities with potential adverse effects on humans and animals. Unfortunately, many pharmaceutical compounds are resistant to breakdown in the environment, hence they have tendency for environmental magnification, since they are designed to be biologically active. Therefore, there is need to evaluate their environmental levels and their possible abatement methods using simple, cheap and low cost techniques, in order to avert their potential toxic consequences. In this research, a cost effective, robust, selective and rugged method for the analysis of antibiotics in water samples using liquid chromatography was developed, and used for monitoring levels of the selected antibiotics in Diep River. Also, an effective remediation procedure for these contaminants in water was developed using activated carbon produced from grape slurry waste.
395

Aquatic toxicity and environmental fate of glyphosate-based herbicides.

January 2002 (has links)
by Tsui Tsz Ki, Martin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 119-138). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abstract --- p.III / Table of Contents --- p.VII / List of Tables --- p.XII / List of Figures --- p.XIV / Abbreviations --- p.XVI / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Research Background --- p.1 / Chapter 1.1.1 --- General description of glyphosate --- p.1 / Chapter 1.1.2 --- Physical and chemical properties of glyphosate --- p.2 / Chapter 1.1.3 --- Commercial formulations based on glyphosate --- p.3 / Chapter 1.1.4 --- Overview of ecotoxicological studies of glyphosate-based formulations --- p.4 / Chapter 1.1.4.1 --- Aquatic toxicity of glyphosate-based formulations --- p.4 / Chapter 1.1.4.2 --- Environmental fate of glyphosate-based formulations in waters --- p.12 / Chapter 1.1.5 --- Interaction of glyphosate and other substances --- p.14 / Chapter 1.2 --- Overview of Aquatic and Sediment Toxicology --- p.16 / Chapter 1.2.1 --- Aquatic toxicology --- p.16 / Chapter 1.2.2 --- Introduction to sediment toxicology --- p.19 / Chapter 1.3 --- "Significance, Outline and Objectives of the Present Study" --- p.20 / Chapter 1.3.1 --- Significance of the research --- p.20 / Chapter 1.3.2 --- Thesis outlines and research objectives --- p.22 / Chapter Chapter 2 --- Aquatic Toxicity of Glyphosate-based Herbicides to Different Organisms and the Effects of Environmental Factors / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Materials and Methods --- p.26 / Chapter 2.2.1 --- Test organisms --- p.26 / Chapter 2.2.2 --- Test chemicals --- p.27 / Chapter 2.2.3 --- Comparison between different organisms --- p.27 / Chapter 2.2.4 --- Environmental factors in modifying Roundup® toxicity --- p.30 / Chapter 2.2.5 --- Analysis of glyphosate concentration --- p.31 / Chapter 2.2.6 --- Validity of tests and statistical analyses --- p.32 / Chapter 2.3 --- Results --- p.32 / Chapter 2.3.1 --- Comparison between different groups of organisms --- p.32 / Chapter 2.3.2 --- Environmental factors in modifying Roundup® toxicity to C.dubia --- p.35 / Chapter 2.4 --- Discussion --- p.36 / Chapter 2.4.1 --- Toxicity of glyphosate to photo synthetic organisms --- p.36 / Chapter 2.4.2 --- pH-associated toxicity of glyphosate --- p.37 / Chapter 2.4.3 --- High potency of surfactant --- p.38 / Chapter 2.4.4 --- Effects of environmental factors on Roundup® toxicity --- p.38 / Chapter 2.5 --- Conclusions --- p.39 / Chapter Chapter 3 --- "Toxicity of Rodeo®, Roundup® Biactive and Roundup® to Water-column and Benthic Organisms and the Effect of Organic Carbon on Sediment Toxicity" / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.2 --- Materials and Methods --- p.43 / Chapter 3.2.1 --- Test chemicals --- p.43 / Chapter 3.2.2 --- Test organisms --- p.43 / Chapter 3.2.3 --- Toxicities to water-column and benthic organisms --- p.44 / Chapter 3.2.4 --- Effect of sediment organic carbon --- p.45 / Chapter 3.2.5 --- Statistical analyses --- p.48 / Chapter 3.3 --- Results --- p.48 / Chapter 3.3.1 --- Toxicities to water-column and benthic organisms --- p.48 / Chapter 3.3.2 --- Effect of sediment organic carbon --- p.49 / Chapter 3.4 --- Discussion --- p.54 / Chapter 3.4.1 --- Different sensitivities between water-column and bethic animals --- p.54 / Chapter 3.4.2 --- Relative toxicities of three herbicides --- p.56 / Chapter 3.4.3 --- Route of exposure of herbicides in sediment to organisms --- p.57 / Chapter 3.4.4 --- Sediment toxicity of glyphosate-based formulations --- p.58 / Chapter 3.4.5 --- Effect of organic carbon on partitioning and toxicity --- p.60 / Chapter 3.5 --- Conclusions --- p.61 / Chapter Chapter 4 --- Joint Toxicity of Glyphosate and Several Selected Environmental Pollutants to Ceriodaphnia dubia / Chapter 4.1 --- Introduction --- p.63 / Chapter 4.2 --- Materials and Methods --- p.65 / Chapter 4.2.1 --- Test organisms and toxicity tests --- p.65 / Chapter 4.2.2 --- Test chemicals --- p.66 / Chapter 4.2.3 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.66 / Chapter 4.2.4 --- Experiment II: Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.67 / Chapter 4.2.5 --- Basic water properties and chemical analyses --- p.69 / Chapter 4.2.6 --- Statistical analyses --- p.70 / Chapter 4.3 --- Results --- p.70 / Chapter 4.3.1 --- General conditions and recovery for spiked chemicals --- p.70 / Chapter 4.3.2 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.71 / Chapter 4.3.3 --- Experiment II: Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.73 / Chapter 4.4 --- Discussion --- p.75 / Chapter 4.4.1 --- Interactions of Roundup® and other toxicants --- p.75 / Chapter 4.4.2 --- Joint toxicity of dissimilar chemicals --- p.77 / Chapter 4.4.3 --- Complexation of glyphosate with metals interactions between liquid/solid phases --- p.79 / Chapter 4.5 --- Conclusions --- p.83 / Chapter Chapter 5 --- Environmental Fate of Glyphosate and its Nontarget Impact: a Case Study in Hong Kong / Chapter 5.1 --- Introduction --- p.85 / Chapter 5.2 --- Materials and Methods --- p.87 / Chapter 5.2.1 --- Description of study sites --- p.87 / Chapter 5.2.2 --- Physicochemical characteristics of different matrices --- p.88 / Chapter 5.2.3 --- Continuous weather monitoring --- p.89 / Chapter 5.2.4 --- Herbicide applications --- p.89 / Chapter 5.2.5 --- Experimental designs --- p.90 / Chapter 5.2.5.1 --- Estuarine enclosure experiment --- p.90 / Chapter 5.2.5.2 --- Freshwater pond experiment --- p.92 / Chapter 5.2.6 --- Schedule of sample collection and sample storage --- p.92 / Chapter 5.2.7 --- Sample preparation --- p.94 / Chapter 5.2.7.1 --- Water samples --- p.94 / Chapter 5.2.7.2 --- Sediment samples --- p.94 / Chapter 5.2.8 --- Sample determination --- p.95 / Chapter 5.2.8.1 --- Pre-column derivatization --- p.95 / Chapter 5.2.8.2 --- High performance liquid chromatography analyses --- p.95 / Chapter 5.2.8.3 --- Calibration of glyphosate and AMPA --- p.95 / Chapter 5.2.8.4 --- Recovery of glyphosate in spiked samples --- p.96 / Chapter 5.2.9 --- Statistical analyses --- p.96 / Chapter 5.3 --- Results --- p.96 / Chapter 5.3.1 --- Site characteristics --- p.96 / Chapter 5.3.2 --- Weather conditions during herbicide application --- p.99 / Chapter 5.3.3 --- Chemical analyses --- p.100 / Chapter 5.3.4 --- In-situ toxicity tests --- p.104 / Chapter 5.4 --- Discussion --- p.106 / Chapter 5.4.1 --- Site-specific factor affecting the environmental fate --- p.106 / Chapter 5.4.1 --- Site-specific factor affecting the environmental fate of glyphosate --- p.106 / Chapter 5.4.2 --- Glyphosate in water and sediment --- p.106 / Chapter 5.4.3 --- Homogeneity of glyphosate in surface water and sediment --- p.109 / Chapter 5.4.4 --- Effect of weather conditions on environmental fate of glyphosate --- p.109 / Chapter 5.4.5 --- Biological impact of Roundup® --- p.110 / Chapter 5.5 --- Conclusions --- p.112 / Chapter Chapter 6 --- General Conclusions --- p.113 / References --- p.119
396

Time series analysis of water quality data

Bhargava, Navin K January 2010 (has links)
Digitized by Kansas Correctional Industries
397

Effects of St. Lucie Estuarine Discharge Water and Thermal Stress on the Coral Montastraea cavernosa

Unknown Date (has links)
Coral reef declines, particularly in coastal zones, have been linked to thermal stress and anthropogenic impacts on water quality. St. Lucie Reef near Stuart, Florida receives increased estuarine efflux as a result of watershed changes and management policies that have substantially altered historic, natural flows. This research used ambient and elevated temperatures (25°C and 30°C, respectively), and offshore versus St. Lucie Estuarine discharge water to investigate the individual and interactive effects of thermal and water quality stress on Montastraea cavernosa, a dominant scleractinian coral species at St. Lucie Reef. These goals were accomplished using ex-situ, factorial, experimental design that was supplemented with existing in-situ monitoring on St. Lucie Reef. Zooxanthellae density and chlorophyll content were evaluated to determine effects on the corals and their symbionts. Zooxanthellae populations were significantly affected by thermal stress. Significant interactions between temperature and water treatment were observed, suggesting that the impacts of discharge water may be supplanted when corals are exposed to thermal stress. In a supplement to the experiment, M. cavernosa colonies transplanted from Palm Beach to St. Lucie Reef demonstrated resilience despite exposure to more variable environmental conditions. Collaborative partnerships with multiple state agencies and local government offices facilitated data sharing to inform decision making for South Florida’s resource management strategies. Creating effective resource management is crucial for the conservation of coastal ecosystems impacted by land-based sources of pollution both locally and globally. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
398

Investigation of the groundwater evolution, interaction and potential radionuclide pollution from the unlined uranium tailings at Langerheinrich mine, Namibia

Shaduka, Ignatius Shikondjeleni January 2016 (has links)
Groundwater is a very scarce and sensitive resource in many parts of the World especially in Africa and in arid areas such as Western Namibia. The Western Namibia hosts the Erongo region which named the Uranium Province world class deposits of uranium and high exploration and mining in the area. The majority of the Erongo region in Namibia depends on groundwater from the Swakop River compartment, hence, is important to understand the mining effects to this precious resource. The safe guarding of groundwater pollution from various sources including mining is vital. The extensive exploration and mining activities in the area raised environmental concerns especially threat to the huge ground water resources and the Aquatic systems in the proximity and hydraulically connected to the Swakopmund and Khan catchments. The study looked the impact of uranium mining in the area specifically focusing on the impact of the unlined uranium tailing dams at Langerheinrich uranium mine on the Gawib River a tributary of the Swakop River. The study reviewed the previous work on the Langerheinrich Uranium Mine that is related to groundwater pollution including the Environmental Impact Assessments carried out by the consultants for the mine. Ten water samples were obtained for the purpose of this study, the samples consists of the groundwater samples, recycled water and the fresh water supply to the mine. The hydrochemistry, stable isotopes and tritium results show that there is contamination from the unlined uranium tailings into the Gawib shallow aquifer system. This could spread to deeper aquifer systems mainly through major structures such as fractures and faults in the area. The contamination plume will also spread downstream to the Gawib River towards the Swakop River unless serious mitigation measures are put in place. There is also a very high risk of the plume to reach the Atlantic Ocean by seasonal flash floods that occurs in the area approximately every after few years. Keywords: Uranium Province, Langerheinrich uranium mine, Groundwater, Pollution, unlined tailings and Gawib River
399

Pharmaceutical Waste in Vermont: Results from a Survey on Purchasing, Use & Disposal

Hart, Christine 01 January 2018 (has links)
Pharmaceutical waste is an emerging form of waste with significant impacts on the environment. This study reports the results of a state-wide phone survey on pharmaceutical purchasing, use and disposal behavior among Vermont residents (n = 421). The objectives of this study were: 1) to compare the demographic nature of populations who purchase and use medicaton to those associated with leftover medication, and 2) to evaluate the impact of disposal behavior in Vermont and to recommend strategies to minimize pollution. The findings of this study showed that approximately 93% of survey participants reported purchasing of medication, 60% reported leftover medication and 25% reported disposing of medications down-the-drain or via municipal trash, both of which are known pathways leading to environmental pollution. Results indicate that pharmaceutical waste is common in Vermont and that disposal behavior may be contributing towards pollution. The conclusion of this study is that better management of pharmaceutical waste is needed to protect the environment and public health.
400

A comparative study of health of rednose labeo baded on the quantitative health assessment index, bioaccumulation and histopathology in the Olifants Rive

Lebepe, Jeffrey January 2012 (has links)
Thesis (M. Sc. (Zoology)) -- University of Limpopo, 2012 / The Olifants River System is one of the most polluted river systems in Southern Africa. The Olifants River catchment is characterized by large-scale mining, power generation, heavy industry and inadequate domestic sewage treatment. Fish and crocodile kills have become commonplace over the past decade, especially in the upper catchment and Kruger National Park. The present study was carried out at Loskop and Flag Boshielo dams, two major impoundments in the Olifants River. Water and sediment samples were collected at each dam during winter (July 2011) and summer (November 2011), frozen and sent to an accredited water lab for chemical analysis. Atleast fifteen fish specimens from each dam were collected during each survey using gill nets. To evaluate the health of red-nose labeo, (Labeo rosae) in the two dams, fish organs were assessed macroscopically using the fish Health Assessment Index (HAI) protocol and a section of liver tissue and gills were dissected out, frozen and sent to an accredited water lab for metal analysis. The remainder liver samples were fixed in 10% buffered formalin and sent to University of Pretoria Pathology Laboratory for histopathological analysis. The concentration of nutrients and ions were higher at Loskop Dam whereas most metal concentrations were found to be higher at Flag Boshielo Dam. The present study categorised Flag Boshielo Dam as oligotrophic with Loskop Dam being mesotrophic. The concentration of aluminium, copper, antimony, iron, lead, selenium and strontium was higher at Flag Boshielo Dam with manganese, silica and zinc being higher at Loskop Dam. Although the concentrations of these toxic constituents varied, there were no significant differences between localities (p>0.05). The constituents that showed high concentrations in sediment were iron and aluminium. The general trend of accumulation in sediment was as follows: Fe > Al > Si > Mn > Zn > Cu > Sb > Sr > Pb > Se at Loskop Dam whereas at Flag Boshielo Dam was as follows: Fe > Al > Mn > Si > Zn > Cu > Sr > Pb > Sb > Se. The liver generally accumulated higher concentrations of metals than the other tissue. General trend of liver > gills > muscle was reported for Al, Cu, Fe, Pb, Sb, Se, Si and Zn with gills > liver > muscle trend being reported for Mn and Sr at both localities. Macroscopic abnormalities were observed for some gills and liver at both localities. Parasite (Lernaea cyprinacea) induced lesions on the skin and mild erosion on the tail fin of some fish were recorded at Flag Boshielo Dam. Most of the histopathological alterations were common at both localities but hydropic glycogen and hyaline droplets were observed only at Loskop Dam, with haemosiderin being observed at Flag Boshielo Dam. Both quantitative HAI results and histopathology have shown that the fish population from Flag Boshielo Dam are in better condition/health than the population Abstract Abstract Page iv from Loskop Dam. There might be a correlation between the nutrient levels and fish health. The overall ecological state is better at Flag Boshielo Dam than Loskop Dam.

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