M.Sc. / The catchment area of the Olifants River has, over a number of years, been exposed to extensive mining, agriculture and urbanisation activities in the Witbank-Middelburg and Phalaborwa regions which has largely contributed to the deterioration of water quality. Of major concern is the influence anthropogenic activities have on the aquatic ecosystem of the Olifants River within the Kruger National Park and how me health of fish residing In these waters is affected. To determine fish health, a biological monitoring method, the Health Assessment Index (H41), was tested for the first time In South Africa. Four surveys were conducted at Mamba and Balule In the Olifants River, Kruger National Park during 1994 (February, May, July and November). An additional survey was conducted in February 1995 at Loskop Dam. Samples of water and sediment were taken for analysis of metals and physical and chemical water parameters. A maximum of 20 Clarias gariepinus fish were sampled at each location. Evaluation of the fish was done according to guidelines set in the HAI and parasite population composition (prevalence, abundance, mean intensity) was determined. Organ and tissue samples including gills, liver, muscle and skin were analysed for the bioaccumulation of chromium, copper, Iron, manganese, nickel, lead, strontium and zinc, using atomic absorption spectrophotomeby. Metal concentrations in the water at Mamba and Balule were within guideline limits, whereas concentrations at Loskop Dam were above guidelines. As reflected by the application of the Aquatic toxicity Index, Loskop Dam presented with the poorest water quality followed by Mamba then Balule. It was found that certain physical and chemical variables namely fluoride, potassium, sulphate and total dissolved solids concentrations at Mamba and Balule were relatively high, particularly during drier months. Metals accumulated in organs and tissues, with the highest concentrations In the gills followed by the liver, skin and muscle. The discriminant analysis, utilising metal bloaccumulation, discriminates between water quality at Mamba and Balule, revealing a 100 % classification probability for each survey. Values obtained In the application of the HAI indicated that variables with good predictor accuracy were plasma protein, all parasites, endoparasites, liver, white blood cell counts, ectoparasites, skin, fins and gills. The discriminant function for the HAI generally Indicated variables similar to those exhibiting high predictor accuracy. The discriminant function showed relatively low classification probability for each survey. In case 1, where separate endo- and ectoparasite variables were Included in the determination of me discriminant function, probability for me entire study ranged between 47.5 % and 84.2 %. In case 2, where endo- and ectoparasite variables were given a refined score rating system, probability ranged between 62.5 % and 100 %. The low classification probability Indicates either the Importance of repetitive testing for this technique or a total departure from it. Results showed that fish populations with higher HAI values are found in water of poorer quality (Mamba), while healthier fish populations i.e. with lower RAI values are found In water of better quality (Balule). Parasite data shows a similar tendency by indicating that ectoparasites are abundant in water of higher quality, while endoparasftes increase in water of poorer quality. The HAI reflects the condition of fish populations in relation to their aquatic environment, therefore, the HA/ gives an indication of water quality and should be used as a first level screening tool. If complemented by a parasite survey, distinguishing between endoand ectoparasites, the results from the HAI will be enhanced.

M.Sc. (Zoology) / Please refer to full text to view abstract

Extractive processes can permanently and significantly reduce the volume, toxicity and mobility of contaminated materials at affected sites. Ethylenediaminetetraacetic acid (EDTA), N-2 (acetamido)iminodiacetic acid (ADA), pyridine2,6-dicarboxylic acid (PDA), and hydrochloric acid (HC1) were evaluated in batch studies for their ability to remove lead (Pb) and cadmium (Cd) from a Superfund soil. The extraction of Pb as a function of time was limited and the order of Pb removal was EDTA > ADA > PDA > HC1. Repeated extractions did not treat the soil below the Pb regulatory limit (1,000 mg/kg); however, the Pb remaining occurs in an immobile form. All extractants treated the soil below the proposed Cd regulatory limit (40 mg/kg) within 1 h. Lead recovery from solution was accomplished by hydroxide precipitation in the presence of excess calcium, and recovery at pH 11 was 70%, 98%, and 97% from the EDTA, ADA, and PDA complexes, respectively. / Department of Natural Resources and Environmental Management

The escalating population growth and increased forestry, mining, agricultural and industrial development in the catchment areas over past years has had a profound effect upon water quality and quantity, resulting in increased pollution levels and a reduction in flow rates. This is cause for concern not only to water users in the upper catchments but also to the down stream user, the Kruger National Park, which is exceedingly dependent on good quality waters in order to maintain and sustain a large variety of ecosystems. This study was therefore aimed at investigating the physicochemical, nutrient and metal concentrations of four major river systems that transect the park, namely the Luvuvhu, Shingwedzi, Letaba and Sabie Rivers. By virtue of its position along South Africa’s eastern border the Kruger National Park (KNP) receives waters from seven major river systems each of which enter via the western boundary, flow eastwards through the park and on into Mozambique. The majority of the catchment areas of these river systems are situated upstream of the park itself making water quality and quantity management an important yet challenging task. Water quality is a significant and powerful determinant of health of aquatic ecosystems. Full assessment of chemical and physical attributes upon the river systems was supported by biological monitoring thus integrating changes in the system over time. Water and sediment samples were collected seasonally between September 2005 to March 2006 at sites outside and inside the borders of the Kruger National Park. Sites outside were located of sufficient distance from the border so as to be regarded as representative of water quality conditions before entering the Park. At each site physico-chemical variables were measured in the water. Two metal bioaccumulation indicator species (Labeobarbus marequensis and Barbus radiatus) were also sampled during this time period. These samples as well as water and sediment samples were analysed for Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Physico-chemical analyses of water and sediment allowed for the separation of the rivers into two distinct groups. The Luvuvhu and Sabie Rivers grouped together showing little deviations from normal water quality guidelines. On the other hand the Shingwedzi and Letaba Rivers deviated from normal values sometimes by large degrees. This was particularly true for the Letaba 1a site for all physico-chemical variables barring temperature. Nutrient concentrations correlated with these findings. Nitrates and Sulphates can be identified as possible problem nutrients; however historic data suggest levels to be acceptable for these river systems. Multivariate analysis of sites with regards to physico-chemical and nutrient concentrations produced three major clusters. Determining factors were conductivity, nitrates, organic content and grain size of 53 μm. Fish were utilised as bioindicator organisms in order to quantify the levels of metals available within each river system. These organisms accumulate metals in their tissues and thus provide not only instantaneous data but rather a time integrate of measure of the bioavailability of metals. Although metal concentrations within water, sediment and fish were not consistently high within one system, three distinct trends were observed. Firstly metal levels were generally found to occur in slightly higher concentrations during the high flow periods when waters were turbid; this could be attributed to increased run off from the surrounding lands as well as increased exposure to sediment bound chemicals released back into the systems. Secondly a trend of high concentrations of Cr, Cu, Fe, Pb, Mn, Ni and Zn was found occurring at the Luvuvhu 1, Luvuvhu 2 and Shingwedzi 1 sites during the high flow sampling. Metal levels at these sites were consistently higher than those recorded at other sampling sites. The last trend noted was that the Sabie River on a whole showed lower metal readings with regard to water, sediment as well as fish samples. In order to integrate bioaccumulation data and metal concentrations in the different phases of the water and sediments an equilibrium partitioning (EP) technique was implemented. Toxic effect-derived quality data is the lowest for Al, Cr, Cu, Pb and Zn, whilst product standard-based criteria produce the lowest values for Fe, Mn and Ni. Cadmium values were found to be similar for both criteria. Results indicate that current water quality guidelines are over protective for Al and Fe, whilst those for Ni and Mn are too lenient. The EP method has not been utilised extensively in South Africa and was carried out for the first time upon these river systems, it is thus essential that further research be carried out. Recommendations are made as to the continued monitoring of these diverse systems. It is suggested that each river be looked at in greater detail and that the development of a field biomonitoring programme should be implemented in order to determine the impacts upon the biological components and the aquatic ecosystem as a whole. Future studies should also look at incorporating the use of aquatic macroinvertebrates (SASS 5) as well as other available techniques in order to supply a more detailed assessment. / Prof. V. Wepener Dr. T. Gyedu-Ababio Prof. J.H.J. Van Vuren

M.Sc. / The upper catchment of the Olifants River, from its origin near Bethal, to its confluence with the Wilge River, north of Witbank, as well as it tributaries, are being subjected to increasing afforestation, mining, power generation, irrigation, domestic and industrial activities. These activities have a profound effect on the water quality and the major point sources of pollution in this area include mines, industries and very importantly, combined sewage purification works, located alongside the river, which, in addition to oxidizable material contains detergents, nutrients, and metals. It was therefore necessary to determine the extent to which these activities affect the water quality of the system. The impact of these activities was therefore addressed by a Water Research Commision Project namely "Lethal and sublethal effects of metals on the physiology of fish" of which the present study investigated effects at two localities, namely in the Olifants River (locality OR1) before its confluence with the Klein Olifants River and a locality in the Klein Olifants River (locality KOR1). Apart from the field study, toxicity tests were also performed in a laboratory, in order to determine the effects of low pH and elevated aluminium concentrations on the haematology, osmoregulation and carbohydrate metabolism of the Mozambique Tilapia, Oreochromis mossambicus as the acidification of soil systems may cause the transfer of aluminium into aqueous solutions, where it may be present in different forms. During the field study, the chemical and physical characteristics of the river water were evaluated, with special attention to the concentrations of certain metals (manganese, copper, chromium, lead, nickel, zinc, iron and aluminium) in the water and sediment, as well as in fish, which are known to accumulate the elements supra and are therefore valuable as indicators of these pollutants. The two fish species used for the investigations were the African sharptooth catfish, Clarias gariepinus and the moggel, Labeo umbratus. Four tissue types were dissected, namely the muscle, liver, skin and gill tissues. The metal concentrations in these organs/tissues, as well as in the water and sediment, were determined in a laboratory with an atomic absorption spectrophotometer. Statistical analyses were performed on the results obtained from this study and the order and extent of bioaccumulation of these metals in the water and sediment were determined, as well as in the fish organs/tissues. Its dependence on the size, sex and species of the fish and the localities and seasons were investigated.

M.Sc. / Metal ions have become an increasing source of pollution in the natural waters of South Africa. This phenomenon is related to the rapid industrial, mining and agricultural activity growth along rivers, especially in the Upper catchment of the Olifants River, Mpumalanga. In general, metal ions have - negative effects on the physiology of fish and other aquatic biota in metal polluted waters. In this study. the sublethal effects of, manganese were determined by exposing the freshwater fish, Oreochromis mossambicus, to this metal in an experimental flow-through system. The exposure times were divided in acute (96 hours) and chronic (26 days) exposures, both at 23 ± 1°C. The results obtained showed changes in the general, haematological, metabolic, osmoregulatory variables, as well as the differential white blood cell counts. These changes indicated several effects in the physiology of a mossainblais after sublethal manganese exposure. Significant differences (P < 0.05) were found between the haematological variables of the control and exposed fish. During chronic exposure, an oxygen deficiency developed due to , the epithelial lifting of gill lamellae. As a result of hypoxia the red blood cell numbers, haemoglobin-, haematocrit and lactate concentrations increased to uplift the depleted oxygen situation. The significant differences (P < 0.05) found in the sodium, potassium,. calcium and chloride concentrations are mainly as a result of gill damage. Manganese showed a disruptive influence on the structural organization of the gill. The differential white blood cell counts performed , showed significant fluctuations. This leucocytosis and leucopenia are normal reactions of the fishes’ body against infections of foreign substances, such as metal ions. It was concluded that the general haematology, metabolism, osmoregulation and differential white blood cell counts can, be used as indicators in detecting the effects of sublethal manganese exposure on fish.

M.Sc. / The recognition of the occurrence, importance and effects of contaminants on food chains and ecosystems has led to the development of biomonitoring programmes that use indicator species to estimate the levels in other parts of the ecosystem. There has been an increased awareness of potential pollution of ecosystems in Gauteng, South Africa, because of increased formal and informal urbanization, industrialization and mining activities. It is essential to obtain clear indications of metal pollution cause-effect relationships at ecosystem level in order to carry out effective management of these ecosystems. The objective was to investigate the application of an ecotoxicologically-based investigation of metals in selected bird species as bioindicators of metal pollution of ecosystems in Gauteng. Three passerine species were used, the Southern Masked Weaver (Ploceus velatus), the Red Bishop (Euplectes orix) and the Red-billed Quelea (Quelea quelea). The sites were selected to represent a theoretical pollution gradient from severely contaminated wetlands in the Vaal Triangle, to moderately contaminated wetlands in the Witwatersrand and Pretoria. A nature reserve in North West Province was chosen as reference site. The sites were Rietvlei in Tshwane, Roodekrans and Olifantsvlei in Johannesburg, Holfontein in the Vaal Triangle and Barberspan in North West Province. Two sampling surveys were carried out, one in 2002 and one in 2005. Feathers were collected for metal analyses. Blood samples were collected for biomarker (oxidative stress and DNA damage) and haematological analyses. The samples were digested using the microwave destruction technique. The metal analyses were carried out using ICP-MS. Oxidative stress enzymes (reduced glutathione content and catalase activity) were analysed in plasma samples and DNA damage was evaluated in red blood cells using the average base-pair length comparisontechnique. Haematological studies were done on the blood samples. The results were compared between the sites and surveys. The levels of stress correlated well with the levels of metals in the feathers. Sites with higher metal levels had higher levels of organism stress. Thus the study showed that the feathers can indeed be used in biomonitoring. Internationally there is a trend to incorporate Ecological Quality Objectives (EcoQOs) into legislation, especially when dealing with metal contamination. Within the framework of EcoQOs developed for birds the monitoring of contaminants forms a specific category of EcoQOs. However, due to a lack of available data, Reference and Target Levels still need to be set. The development of EcoQOs is especially important at this stage in South Africa. The recently promulgated National Biodiversity Act (10 of 2004) specifically provides for the preparation of conservation plans for identified ecosystems that are important because of their goods and services that they provide. Since there is no management tool available at present to develop a suitable management plan, the setting of EcoQOs that are in line with international standards and practices will be of immeasurable value to implementing the Act. Feathers from museum specimens were used to determine the Reference Levels for the various metals in the feathers. The Target Levels were calculated from the Reference Levels. These were compared to the Current Levels and the EcoQOs were determined for the metal levels in the feathers in weaver in Gauteng, South Africa. / Prof. V. Wepener

Orientador: Gisleiva Cristina dos Santos Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-26T17:24:55Z (GMT). No. of bitstreams: 1 Domingues_LucieneGachetFerrari_M.pdf: 2343160 bytes, checksum: d94ee8fa2a1db00758930c4259251ab1 (MD5) Previous issue date: 2015 / Resumo: Do processo de fundição de metais é gerado um resíduo chamado de areia descartada de fundição (ADF), o qual é prioritariamente destinada para aterros sanitários, tornando-se um passivo ambiental de grande proporção. O Brasil gera cerca de 3 milhões de toneladas de ADF por ano, o que propiciou a criação de normas para gerenciamento e aplicação deste resíduo em outras atividades, principalmente na construção civil. O objetivo desta pesquisa foi de verificar a viabilidade ambiental e econômica na utilização de misturas de solo + ADF em teores de 30%, 50% e 70%, na cobertura de resíduos sólidos urbanos em aterros sanitários. A mistura de solo + 70% ADF foi a que apresentou funcionalidade na cobertura das camadas intermediárias de resíduos sólidos, nos aspectos físico (permeabilidade), mecânico (resistência ao cisalhamento), ambiental (classe II-A e não tóxico) e econômico (menor custo). Portanto, este estudo comprovou a viabilidade ambiental e econômica deste inovador modelo de operação e gestão proposto para maciços de aterros sanitários / Abstract: From the metal casting process is generated the waste foundry sand (WFS), which is primarily discarded in landfills, becoming an environmental liability of large proportions. The Brazil generates about 3 million tons per year of WFS, which led to the creation of standards for management and implementation of this residue in other activities, especially in construction. The objective of this research was to verify the environmental and economic viability in the use of soil-foundry sand mixtures in 30%, 50% and 70% level of substitution, in the coverage of solid wastes landfills. The soil + 70% WFS mixture presented the feature in the intermediate layers of solid waste landfills coverage, in the physical (permeability), mechanical (shear strength), environmental (II-A class and non-toxic) and economic (lower cost) aspects. Therefore, this study proved the environmental and economic feasibility of this innovative operating model and management proposed for massive landfills / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

Neste trabalho foram determinados os parâmetros de metalurgia do pó para utilizar o resíduo do processo de jateamento para transformá-lo em componentes. O resíduo foi avaliado quanto as suas características físicas e microestruturais, e os corpos sinterizados, quanto a microestrutura, a dureza e a densidade. As partículas do resíduo foram caracterizadas quanto a distribuição de tamanho por peneiramento apresentando uma distribuição gaussiana com diâmetro médio de partícula de 180 µm. Na avaliação da morfologia do resíduo por análise de imagem foi possível identificar que o formato das partículas maiores que 300 µm foi predominantemente esférico, com circularidade de 0,86, enquanto que nas partículas menores o formato foi de placas, com circularidade de 0,76. As propriedades de fluidez determinadas pelos métodos de ângulo de repouso e de funil Hall tiveram valores próximos dos materiais comerciais. A densidade por Arquimedes dos corpos verde e sinterizados e as densidades aparente de Arnold e de funil Hall foram avaliadas. A técnica de densidade batida foi utilizada para determinar a mistura ótima com maior densidade, definida pela composição de 1/6 de finos + 1/6 de médios + 2/3 de grossos a partir de misturas previamente estabelecidas de acordo com o planejamento de misturas de rede simplex com pontos adicionais. As diferentes misturas foram compactadas em prensa uniaxial com acionamento simples à 990 MPa de pressão e posteriormente sinterizadas na temperatura de 1200ºC em atmosfera de argônio tecnicamente puro. Os corpos sinterizados apresentaram o estágio de crescimento do pescoço, uma microestrutura com presença de cementita globulizada em uma matriz ferrítica e microdureza de 230HV. Neste trabalho, foi possível determinar os parâmetros da metalurgia do pó e a mistura de tamanhos das partículas para obter componentes com densidade de 90% em relação a teórica, densidade essa encontrada em produtos industrializados. Para realização deste estudo, o equipamento de densidade batida foi projetado e construído pelo autor. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-07-05T12:46:14Z No. of bitstreams: 1 Dissertacao Leonardo Meneghel.pdf: 10589642 bytes, checksum: b89cfd283bc311ec17c4657889bc1d3a (MD5) / Made available in DSpace on 2017-07-05T12:46:14Z (GMT). No. of bitstreams: 1 Dissertacao Leonardo Meneghel.pdf: 10589642 bytes, checksum: b89cfd283bc311ec17c4657889bc1d3a (MD5) Previous issue date: 2017-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / This research has determined the parameters of powder metallurgy in order to use the wasted powder from the shot blasting process and transform it in components. The wasted was evaluated by its physical and micro-structural characteristics, and the sintered bodies were characterized for its micro-structural, hardness and density. The particles of the wasted powder were characterized according the size distribution in sieving and found a Gaussian distribution with a medium particle dimension of 180 µm. In the morphologic evaluation of the wasted by image analysis, it was possible to identify that the predominant shape of the particles bigger than 300 µm were spherical, with circularity of 0.86, while the smaller particles were plate-shaped with the circularity of 0.76. The properties of flow rate determined by the Angle of Repose and the Hall Flowmeter Funnel methods achieved similar values of commercial powders. The Archimedes density of green and sintered bodies and the apparent density of Arnold and Hall Flowmeter Funnel were evaluated. The optimal mixture with higher density, composed by 1/6 small + 1/6 medium + 2/3 big, was found from pre-established mixtures according to the simplex lattice design and the technique of tapped density. Different mixtures were compacted in an uniaxial press with a single-action in 990 MPa and later sintered in 1200ºC with a controlled argon atmosphere. The sintered bodies showed a growing neck stage, a micro-structure with globular cementite in a ferritie matrix, and the micro-hardness of 208 HV. In this work, it was possible to determine the parameters of powder metallurgy and the mixture of particle sizes in order to obtain components with 90% density in relation to theoric density, which is found in commercial products. In order to complete this study, the tapped density equipment was designed and built by the author.

Neste trabalho foram determinados os parâmetros de metalurgia do pó para utilizar o resíduo do processo de jateamento para transformá-lo em componentes. O resíduo foi avaliado quanto as suas características físicas e microestruturais, e os corpos sinterizados, quanto a microestrutura, a dureza e a densidade. As partículas do resíduo foram caracterizadas quanto a distribuição de tamanho por peneiramento apresentando uma distribuição gaussiana com diâmetro médio de partícula de 180 µm. Na avaliação da morfologia do resíduo por análise de imagem foi possível identificar que o formato das partículas maiores que 300 µm foi predominantemente esférico, com circularidade de 0,86, enquanto que nas partículas menores o formato foi de placas, com circularidade de 0,76. As propriedades de fluidez determinadas pelos métodos de ângulo de repouso e de funil Hall tiveram valores próximos dos materiais comerciais. A densidade por Arquimedes dos corpos verde e sinterizados e as densidades aparente de Arnold e de funil Hall foram avaliadas. A técnica de densidade batida foi utilizada para determinar a mistura ótima com maior densidade, definida pela composição de 1/6 de finos + 1/6 de médios + 2/3 de grossos a partir de misturas previamente estabelecidas de acordo com o planejamento de misturas de rede simplex com pontos adicionais. As diferentes misturas foram compactadas em prensa uniaxial com acionamento simples à 990 MPa de pressão e posteriormente sinterizadas na temperatura de 1200ºC em atmosfera de argônio tecnicamente puro. Os corpos sinterizados apresentaram o estágio de crescimento do pescoço, uma microestrutura com presença de cementita globulizada em uma matriz ferrítica e microdureza de 230HV. Neste trabalho, foi possível determinar os parâmetros da metalurgia do pó e a mistura de tamanhos das partículas para obter componentes com densidade de 90% em relação a teórica, densidade essa encontrada em produtos industrializados. Para realização deste estudo, o equipamento de densidade batida foi projetado e construído pelo autor. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES. / This research has determined the parameters of powder metallurgy in order to use the wasted powder from the shot blasting process and transform it in components. The wasted was evaluated by its physical and micro-structural characteristics, and the sintered bodies were characterized for its micro-structural, hardness and density. The particles of the wasted powder were characterized according the size distribution in sieving and found a Gaussian distribution with a medium particle dimension of 180 µm. In the morphologic evaluation of the wasted by image analysis, it was possible to identify that the predominant shape of the particles bigger than 300 µm were spherical, with circularity of 0.86, while the smaller particles were plate-shaped with the circularity of 0.76. The properties of flow rate determined by the Angle of Repose and the Hall Flowmeter Funnel methods achieved similar values of commercial powders. The Archimedes density of green and sintered bodies and the apparent density of Arnold and Hall Flowmeter Funnel were evaluated. The optimal mixture with higher density, composed by 1/6 small + 1/6 medium + 2/3 big, was found from pre-established mixtures according to the simplex lattice design and the technique of tapped density. Different mixtures were compacted in an uniaxial press with a single-action in 990 MPa and later sintered in 1200ºC with a controlled argon atmosphere. The sintered bodies showed a growing neck stage, a micro-structure with globular cementite in a ferritie matrix, and the micro-hardness of 208 HV. In this work, it was possible to determine the parameters of powder metallurgy and the mixture of particle sizes in order to obtain components with 90% density in relation to theoric density, which is found in commercial products. In order to complete this study, the tapped density equipment was designed and built by the author.