Atividades específicas do 226Ra dissolvido foram medidas e atividades de 226Ra associado ao material em suspensão foram estimadas em águas subterrâneas extraídas de dois poços perfurados em granitos do Plúton Meridional, Granitóides de Morungaba, no leste do Estado de São Paulo. / Specifc activities of dissolved 226Ra isotope were measured and 226Ra isotope activities associated to suspended solids were estimated in ground waters drawn from two wells drilled in a fracturated granitic aquifer of the Meridional Pluton, Morungaba Granitoids, eastern São Paulo State.

O modelo econômico extrair, transformar, descartar da atualidade está atingindo seus limites físicos. Confrontando-se com questões de disponibilidade de recursos A economia circular é uma alternativa atraente que busca redefinir a noção de crescimento, com foco em benefícios para toda a sociedade. Dentro dessa nova visão, conceitos de tratamentos descentralizados e sustentáveis de saneamento que concentram-se no tratamento e na reciclagem dos recursos presentes nas águas residuais domésticas são considerados. Assim, a partir de uma água residuária é possível obter três recursos principais: a bioenergia, nutrientes e água. Esta pesquisa teve por objetivo principal avaliar a produção de um efluente propício ao reúso não potável, a partir de água negra. A água negra foi tratada anaerobiamente (reator UASB) para remoção de matéria orgânica, seguindo para um fotobiorreator para remoção de nutrientes, com consequente separação da biomassa algal por flotação por ar dissolvido. Neste ponto foi avaliada a absorção de nutrientes pelas microalgas e o crescimento de sua biomassa. Após a flotação, o efluente foi desinfetado, avaliada assim, a inativação de coliformes totais e Escherichia coli, bem como de Giardia spp. e Cryptosporidium spp. no sistema de tratamento. O reator UASB manteve níveis elevados de remoção de matéria orgânica (DQO), com remoções de 70%. Apresentando uma média de remoção de Escherichia coli e coliformes fecais entre 1 e 3 log. Para protozoários essa remoção foi entre 0,5 e 1,5 log. O fotobiorreator, obteve satisfatório crescimento da biomassa, sem controle de temperaturas ou suplementação de CO2, apresentou também remoção/inativação de Escherichia coli e coliformes totais, com valores entre 0,50 a quase 3,0 log, apresentando de modo geral maior remoção/inativação para Escherichia coli. Foi observado remoção de protozoários e coliformes pela flotação por ar dissolvido, acarretando uma maior concentração destes na biomassa removida. O melhor desinfetante individual foi o cloro, em razão da inativação. No entanto, o ozônio foi o que melhor obteve remoção (oxidação) de matéria orgânica. Em relação aos desinfetantes aplicados de modo sequencial ou simultâneos, foi observado que a melhor inativação foi promovida pelo ensaio sequencial com ozônio e cloro, com inativação de até 3,10 e 3,38 log para Escherichia coli e coliformes totais, respectivamente. Com efeito sinérgico em relação a aplicação individual destes desinfetantes. Recomenda-se o uso do sistema para o tratamento descentralizado, principalmente em pequenas comunidades e em áreas rurais. / The current economic \"extract, transform, discard\" model is reaching its physical limits. Confronting with issues of resource availability Circular economics is an attractive alternative that seeks to redefine the notion of growth, with a focus on benefits for the whole society. Within this new vision, concepts of decentralized and sustainable sanitation treatments that focus on the treatment and recycling of resources present in domestic wastewater are considered. Thus, from a wastewater it is possible to obtain three main resources: bioenergy, nutrients and water. The main objective of this research was to evaluate the production of an effluent conducive to non-potable reuse from black water. The black water was treated anaerobically (UASB reactor) to remove organic matter, followed by a photobioreactor to remove nutrients, with consequent separation of the algal biomass by dissolved air flotation. At this point, the nutrient uptake by microalgae and the growth of their biomass were evaluated. After flotation, the effluent was disinfected, thus evaluating the inactivation of total coliforms and Escherichia coli, as well as Giardia spp. and Cryptosporidium spp. in the treatment system. The UASB reactor maintained high levels of organic matter removal (COD), with removals of 70%. Presents an average removal of Escherichia coli and faecal coliforms between 1 and 3 log. For protozoa this removal was between 0.5 and 1.5 log. The photobioreactor, obtained satisfactory biomass growth, without temperature control or CO2 supplementation, also showed removal/inactivation of Escherichia coli and total coliforms, with values ranging from 0.50 to almost 3.0 log, generally presenting greater removal inactivation for Escherichia coli. Removal of protozoa and coliforms by flotation by dissolved air was observed, leading to a higher concentration of these in the biomass removed. The best individual disinfectant was chlorine, due to inactivation. However, ozone was the one that best obtained removal (oxidation) of organic matter. Regarding disinfectants applied sequentially or simultaneously, it was observed that the best inactivation was promoted by the sequential test with ozone and chlorine, with inactivation of up to 3.10 and 3.38 log for Escherichia coli and total coliforms, respectively. With synergistic effect in relation to the individual application of these disinfectants. It is recommended to use the system for decentralized treatment, especially in small communities and in rural areas.

Orientador: Wilson de Figueiredo Jardim / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-19T06:01:40Z (GMT). No. of bitstreams: 1 Raimundo_CassianaCarolinaMontagner_D.pdf: 6486329 bytes, checksum: eb2082b97701f19b66fc4e6dc033da3f (MD5) Previous issue date: 2011 / Resumo: O objetivo deste trabalho foi avaliar, através de um perfil anual, a qualidade dos mananciais e da água tratada de Campinas (SP) em relação à presença de cafeína, estrona, 17b-estradiol, estriol, progesterona, testosterona, 17a-etinilestradiol, mestranol, levonorgestrel, dietilestilbestrol, triclosan, 4-n-octilfenol, 4-n-nonilfenol, bisfenol A, fenolftaleína e atrazina empregando extração em fase sólida (SPE) e cromatografia líquida acoplada ao espectrômetro de massas (LC-MS/MS), e verificar o potencial estrogênico das amostras usando o bioensaio Bioluminesce Yeast Estrogen Screening (BLYES). Os resultados mostraram a presença de seis dos 16 compostos investigados em pelo menos uma amostra de água tratada. A estrona foi detectada apenas uma vez. Concentrações de atrazina de até 687 ng L foram determinadas nas amostras provenientes do rio Capivari, e nas amostras de água tratada provenientes do rio Atibaia as concentrações não passaram de 42 ng L. A fenolftaleína foi determinada em apenas uma campanha em todas as amostras provenientes do rio Atibaia em concentrações de até 20 ng L. As concentrações médias de bisfenol A e triclosan foram 7 e 17 ng L, respectivamente. Nos mananciais foram determinados 13 dos 16 compostos investigados. Todas as amostras de água bruta e tratada apresentaram concentrações de cafeína que variaram significativamente entre os períodos de seca e cheia dos rios. As estações de tratamento de água de Campinas, operando no sistema convencional foram capazes de remover entre 30 e 99% dos contaminantes investigados. No mais, 40 % das amostras de água tratada apresentaram atividade estrogênica positiva (entre 0,01 e 1,33 ngE2equiv L) e todas as amostras de água bruta apresentaram estrogenicidade entre 0,06 e 6,54 ngE2equiv L. Sendo que estas foram maiores nos períodos de estiagem / Abstract: The purpose of this work was to evaluate an annual profile of both source of supply and drinking water quality in the city of Campinas (São Paulo State) in relation to the presence of caffeine, estrone, 17b-estradiol, estriol, progesterone, testosterone, 17a-ethynylestradiol, mestranol, levonorgestrel, diethylstilbestrol, triclosan, 4-n-octylphenol, 4-n-nonylphenol, bisphenol A, phenolphthalein and atrazine using Solid Phase Extraction (SPE) and Liquid Chromatography with Tandem Mass Spectrometry Detection (LC-MS/MS), and make sure the estrogenic potential of samples using Bioluminesce Yeast Estrogen Screening bioassay (BLYES). Results showed the presence of six of the 16 compounds investigated in least one sample of drinking water (estrone, triclosan, bisphenol A, phenolphthalein, atrazine and caffeine). Atrazine concentrations up to 687 ng L were found in drinking water samples from the Capivari River. In drinking water samples from the Atibaia River, the concentrations did not exceed 42 ng L. Phenolphthalein was determined in only one campaign in both raw and treated water from the Atibaia River at concentrations around 20 ng L. Average concentrations of bisphenol A and triclosan in drinking water samples were 7 and 17 ng L, respectively. Thirteen of the 16 investigated compounds were determined in surface waters. All samples of raw and treated water showed concentrations of caffeine that varied significantly between dry and wet seasons. The conventional water treatment plants in Campinas were able to remove between 30 and 99 % of the investigated contaminants. The estrogenic activity was evaluated using BLYES bioassay, where 40% of drinking water samples showed positive estrogenic activity (between 0.01 and 1.33 ngE2equiv L) and all samples of surface water presented estrogenic activity between 0.06 and 6.54 ngE2equiv L. These values were higher in dry winter periods / Doutorado / Quimica Analitica / Doutor em Ciências

Orientador: Bastiaan Philip Reydon / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Economia / Made available in DSpace on 2018-08-21T00:47:00Z (GMT). No. of bitstreams: 1 PortugalJunior_PedrodosSantos_M.pdf: 1871526 bytes, checksum: 0a55b7a8668cbc04ead535c2f1477e70 (MD5) Previous issue date: 2012 / Resumo: O presente estudo tem por principal objetivo analisar a aplicação de padrões de gestão ambiental em empresas de água mineral do Circuito das Águas do Sul de Minas Gerais. Nesse contexto são analisadas as principais linhas de pensamento sobre a relação entre economia e meio ambiente, dando um foco maior à economia ecológica e ao ecodesenvolvimento, e suas contribuições para a internalização da questão ambiental na tomada de decisão das empresas por meio de instrumentos (comando e controle, econômicos e certificadores). Posteriormente, apresentam-se dados que demonstram o comportamento desse segmento de mercado no Brasil, bem como suas principais perspectivas para os próximos anos. Ao final apresentam-se os resultados qualitativos da pesquisa sobre os níveis de gestão ambiental adotados por três empresas distintas: Copasa Águas Minerais de Minas S/A (detentora das empresas de Caxambu, Cambuquira e Lambari), Nestlé-Waters Brasil - Bebidas e Alimentos Ltda (empresa de São Lourenço) e Mineração Água Padre Manoel (do município de Passa Quatro); bem como a opinião do Comitê de Bacia Hidrográfica do Rio Verde sobre esse tema. Ao final verifica-se que a aplicação de gestão ambiental nessas empresas depende diretamente de sua política interna que, na maioria das vezes, apenas cumpre as determinações da legislação vigente. Salienta-se assim que o principal problema nesse segmento é a controvérsia existente na legislação em vigor que considera a água mineral como minério e não como recurso hídrico. Fica evidente que a aplicação dos instrumentos de comando e controle atuais (Código de Águas Minerais e resoluções do DNPM) não é suficiente para a adoção de padrões avançados de gestão ambiental nessas empresas, tornando-se necessária a integração das águas minerais em instrumentos de comando e controle mais avançados, como a PNRH e PNRS, juntamente com a aplicação de instrumentos econômicos como a cobrança pelo uso desse recurso e subsídios aos custos de controle, focando sempre a exploração da água mineral de acordo com a sua capacidade de renovação / Abstract: This study aims to examine the application of environmental management standards in the mineral water companies of Circuito das Águas do Sul de Minas Gerais. In this context we analyze the main lines of thought on the relationship between economics and environment, giving a greater focus on ecological economics and eco-development, and their contributions to the internalization of environmental concerns in decision making of enterprises by means of instruments (command and control, economic and certifiers). Subsequently, we present data that demonstrate the behavior of this market segment in Brazil, as well as its main perspectives for the next years. At the end we present the results of qualitative research on the levels of environmental management adopted by three different companies: Copasa Águas Minerais de Minas S/A (holding firms Caxambu, Cambuquira and Lambari), Nestlé-Waters Brazil - Bebidas e Alimentos Ltda. (Company of São Lourenço) Mineração Água Padre Manoel (the city of Passa Quatro), as well as the opinion of the Comitê da Bacia Hidrográfica do Rio Verde on the subject. At the end it turns out that the application of environmental management in these firms depends directly on its internal policy that, in most cases, only fulfills the requirements of current legislation. It should be noted as well that the main problem in this segment is controversy in the current legislation it considers mineral water as an ore and not as water resource. It is evident that the application of command and control current (Código de Águas Minerais and DNPM resolutions) is not sufficient for the adoption of advanced standards of environmental management in these companies, making necessary the integration of mineral water in instruments of command and control more advanced, as PNRH PNRS, along with the application of economic instruments such as charging for the use of this feature and subsidies to control costs, always focusing on the exploitation of mineral water according to their capacity for renewal / Mestrado / Desenvolvimento Economico, Espaço e Meio Ambiente / Mestre em Desenvolvimento Econômico

The coal industry of Mpumalanga Province is faced with the problem of developing cost effective ways of using large volumes of calcium and magnesium sulphate enriched waste waters. Use of the waste waters for agricultural production may contribute as a stabilising factor with regard to yields in this high potential agricultural area. The objectives of this study were to determine the effect of such waste waters on yield and to compare crop response to calcium and magnesium sulphate salinity at different nutrient levels. Two separate glasshouse experiments were conducted. Wheat (Triticum aestivum L. cv. SST 825) was grown in calcium and magnesium sulphate salinised nutrient solutions (Ca:Mg 2: 1) with differential levels of NO3, NH4, P and K. A soil pot experiment was subsequently conducted with maize (Zea mays, cv. PAN 6256), three gypsum and magnesium sulphate salinity levels and a 6 x 2 x 3 factorial combination of N, P and K. Calcium and magnesium sulphate salinity decreased the biomass production of both crops. This was mainly due to interactions of Mg with the uptake of essential nutrients in wheat and a Mg toxicity andlor Ca deficiency induced by high levels of Mg andlor SO4 in maize. The application of NO3, NH4, and K at rates different from the level considered beneficial for non-saline conditions improved wheat growth under sulphate saline conditions. Strongly inhibitory salinity levels controlled the maize yield of the highest salinity treatment regardless of the level of fertiliser application. A beneficial effect of higher NH4 supply was observed in both experiments. This can be ascribed to the antagonistic effect that NH4 exerted on Mg concentrations in plants (both experiments) and SO4 (soil pot experiment) and/or to a higher N-utilization efficiency where N was supplied as NH4 compared to NO3. Differential application levels of P had no effect on the yield of wheat. Phosphorus concentrations in maize were marginal to low, even at extremely high soil Bray I-P levels. This was probably caused by the precipitation of P as insoluble calcium phosphate complexes in the soil andlor between the free space of the cortex cells of plant roots. These results could also indicate that the Bray I extraction method does not give a true reflection of plant available P in sulphate saline soil. Further experimentation is needed to verify these results under field conditions and determine the optimal rate, method and timing of especially NH4 and PO4 fertilisers when irrigating crops with these calcium and magnesium sulphate enriched waste waters. / Dissertation (MSc (Plant Production and Soil Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Les eaux minérales naturelles se distinguent de l’eau potable par leur contenu en sels minéraux et en éléments traces. Leur utilisation à des fins thérapeutiques s’effectue sous contrôle médical dans des établissements thermaux. La gestion des réseaux de distribution ainsi que la qualité microbiologique de l’eau font l’objet de réglementations. Malgré la mise en place de procédures spécifiques, les établissements thermaux sont régulièrement confrontés à des contaminations microbiologiques majoritairement dues à P. aeruginosa. Ce pathogène opportuniste possède d’importantes capacités d’adaptation, de résistance et de persistance dans l’environnement, notamment sous forme de biofilms. L’objectif de ces travaux de thèse est d’apporter des éléments de compréhension sur le comportement de P. aeruginosa dans les réseaux de distribution d’eau minérale naturelle et de valider l’efficacité de produits de traitement. L’influence de la composition minérale de 3 eaux sur les capacités à former du biofilm de 9 souches de P. aeruginosa d’origines diverses a pu être démontrée. Il apparait que les quantités de biofilms produites au bout de 24 h sont moins importantes pour la minéralisation forte. La modulation de la production de facteurs de virulence en fonction de la qualité de l’eau est corrélée à l’action spécifique de certains ions et à la biodisponibilité du fer. En conditions de minéralisation forte il a été montré que les matériaux organiques favorisent la formation de biofilm de P. aeruginosa tandis que les matériaux métalliques ont tendance à la défavoriser. L’efficacité d’une séquence de traitement de postes de soins a pu être validée sur un modèle de biofilm âgé de 24 h et sur tous les matériaux. / Natural mineral waters are distinguished from drinking water bytheir content in minerals and trace elements. Their use for therapeuticpurposes under medical control is performed in spas. Management ofdistribution networks and the microbiological quality of water are subjectto regulations. Despite the establishment of specific procedures, spas areregularly confronted with microbiological contamination mainly due to P.aeruginosa. This opportunistic pathogen has substantial adaptive capacity,resistance and persistence in the environment, under biofilm.The aim of this thesis work is to bring understanding on the P.aeruginosa behaviour in the natural mineral water distribution networksand validate the effectiveness of treatment products.The influence of the mineral composition of 3 waters on biofilmformation capacity of 9 P. aeruginosa strains of various origins could bedemonstrated. It appears that the amount of biofilm produced after 24 hare less important for the strong mineralization. Modulation of theproduction of virulence factors depending on the water quality iscorrelated to the specific action of certain ions and iron bioavailability. Inhigh mineralization conditions it has been shown that organic materialspromote biofilm formation of P. aeruginosa while metallic materials tendto disadvantage it. The efficiency of a treatment sequence of a patient pointof use has been validated on the 24 h biofilm model and on all materials.

A LLE-GC-MS method was developed to detect PPCPs in surface water samples from Big Cypress National Park, Everglades National Park and Biscayne National Park in South Florida. The most frequently found PPCPs were caffeine, DEET and triclosan with detected maximum concentration of 169 ng/L, 27.9 ng/L and 10.9 ng/L, respectively. The detection frequencies of hormones were less than PPCPs. Detected maximal concentrations of estrone, 17β-estradiol, coprostan-3-ol, coprostane and coprostan-3-one were 5.98 ng/L, 3.34 ng/L, 16.5 ng/L, 13.5 ng/L and 6.79 ng/L, respectively. An ASE-SPE-GC-MS method was developed and applied to the analysis of the sediment and soil area where reclaimed water was used for irrigation. Most analytes were below detection limits, even though some of analytes were detected in the reclaimed water at relatively high concentrations corroborating the fact that PPCPs do not significantly partition to mineral phases. An online SPE-HPLC-APPI-MS/MS method and an online SPE-HPLC-HESI-MS/MS method were developed to analyze reclaimed water and drinking water samples. In the reclaimed water study, reclaimed water samples were collected from the sprinkler for a year-long period at Florida International University Biscayne Bay Campus, where reclaimed water was reused for irrigation. Analysis results showed that several analytes were continuously detected in all reclaimed water samples. Coprostanol, bisphenol A and DEET’s maximum concentration exceeded 10 µg/L (ppb). The four most frequently detected compounds were diphenhydramine (100%), DEET (98%), atenolol (98%) and carbamazepine (96%). In the study of drinking water, 54 tap water samples were collected from the Miami-Dade area. The maximum concentrations of salicylic acid, ibuprofen and DEET were 521 ng/L, 301 ng/L and 290 ng/L, respectively. The three most frequently detected compounds were DEET (93%), carbamazepine (43%) and salicylic acid (37%), respectively. Because the source of drinking water in Miami-Dade County is the relatively pristine Biscayne aquifer, these findings suggest the presence of wastewater intrusions into the delivery system or the onset of direct influence of surface waters into the shallow aquifer.

The Devils Lake defection of 2005 demands a re-evaluation of the venerable Boundary Waters Treaty (BWT) between Canada and the United States. Why was the long-successful water agreement unable to solve this relatively minor dispute? More importantly, given irregularities between theoretical assertions and institutional history, what theory of international relations best explains a cooperative agreement that spans a near-century? Due to the complexities of shared river systems, any theory that seeks to explain international cooperation must adequately encompass three separate sources of state motivation. First, it must explain the technical, basin-position-driven realities that affect state attitudes towards negotiations. Second, it must explain the longer-term strategic factors that can inspire states to accept immediate losses for subsequent gains. Finally, it must acknowledge domestic sources of influence and understand how these forces constrain the state vis-à-vis others. This paper argues that liberalism, as defined by Andrew Moravcsik, is the best theoretical candidate. This is proven by comparing interpretations of the BWT history through realist, neoliberal, constructivist, and liberal lenses. After identifying and examining each theory's strengths and weaknesses, liberalism emerges as the most holistic view and should be favoured as a primary explanatory theory. Liberalism's theoretical underpinnings – interest group politics – best handles the technical, strategic, and domestic influences that affect Canada-US water relations. Whether examining what prompted efforts to initiate a water-sharing agreement, explaining the agreement's final structure, determining the impetus for continued cooperation, or identifying the incentives to finally break from treaty obligations, liberalism provides the most satisfying solutions. Though derived from the Canada-US border relationship, liberalism's superiority is not limited to the North American watershed. Because the factors examined are common to all shared international river systems and the paper's results are scalable, this suggests that liberalism will continue to be the appropriate primary IR theory to employ when examining state decision-making regarding water-sharing agreements. / Arts, Faculty of / Political Science, Department of / Graduate

The influence of parent lithology on the development of soil biogeochemical environments and their microbial diversity is explored by characterising soil profiles with respect to their mineral, solution and organic chemistry. Soil profiles were collected from a total of 17 sites, above basalt, granodiorite, shale, sandstone and limestone, across Northern Ireland. The soil system developed above basalt was examined to assess the development of soil bio-physicochemical properties and microbial diversity through the profile. These basalt soils showed two distinct horizons have developed in the previous 15’000 years, where soils from the top 20 cm of the profile were highly influenced by the interactions of soil minerals with soil organic and biological processes. In line with the observed differences in soil properties the microbial community structure varied; in the surface soils the community composition was dominated by root-associated bacteria. However the relative abundance of phyla affiliated with nutrient-limited conditions increased in samples from the base of the profile. Detailed examination of the soil profiles above granodiorite, shale, sandstone and limestone revealed large variations in soil geochemistry between profiles, reflecting the mineral geochemistry of the parent rock. Molecular analysis of SOM revealed compositional changes with depth were comparable between profiles; however TOC concentrations were consistently higher in the soil profiles above basalt suggesting greater stabilisation of SOM in these soils. The chemistry of the soil waters was not reflective of the parent rocks; however variations in soil texture, specifically the abundance of less reactive residual minerals in the sandstone and limestone soils, led to higher concentrations of soluble elements in these soils. Soil pH and DOC were found to have a large control on buffering the release of free Al, Cr and Fe ions into solution. The microbial communities in near-surface soils were similar to each other, regardless of lithology, and were dominated by Proteobacteria, Actinobacteria, and Acidobacteria. However microbial diversity shifted with depth; the abundance of Actinobacteria decreased and Nitrospirae increased, and between rock types where soils next to the basalt, shale and granodiorite bedrock contained sequences affiliated with novel Candidate Phyla AD3 and GAL15. In these soils differences in SOM composition were the main driver of the observed variation with depth, however where labile SOM was depleted, mineral and solution geochemistry may have a larger control on the community composition. To assess the influence of parent lithology on selenium mobility, soils above basalt and granodiorite were amended with sodium selenate. Under anaerobic conditions, the proportion of soluble selenate removed varied (39-77 %) depending on the sample through a combination of abiotic and microbial reduction processes. However, under aerobic conditions, larger concentrations of selenate remained in solution (79-100%).

Surface waters used for irrigation purposes in South Africa have been found to be of poor microbiological quality and to be contaminated with human pathogens. These pathogens can be transferred from contaminated water onto fresh produce and potentially cause human infections. Cryptosporidium and Giardia are waterborne parasitic protozoa that have been found in surface waters worldwide. They can cause morbidity in infected individuals and be lethal when infecting people with compromised immunity. This study was divided into two phases. The first phase was a field survey aimed at determining the incidence of human pathogens Cryptosporidium, Giardia and Salmonella spp. in rivers used for irrigation purposes in South Africa as well as on vegetables irrigated with these rivers. The rivers selected were from three different provinces of South Africa. The relationship between faecal indicators and the presence of Cryptosporidium oocysts and Giardia cysts was also investigated. Out of the 30 water samples analysed, 43% were positive for Cryptosporidium oocysts, 23% tested positive for Giardia cysts and 27% were positive for Salmonella spp. However, no Cryptosporidium oocysts or Giardia cysts were found on the vegetables analysed. No significant differences in the prevalence of Cryptosporidium and Giardia and indicator parameters were observed between the three rivers. Using a logistic regression model, no significant correlations were observed between the incidence of faecal indicators and the presence of Cryptosporidium oocysts and Giardia cysts. In the second phase of the study, the individual and combined effects of chlorine, blanching, blast freezing and microwave heating on Cryptosporidium parvum oocysts inoculated on green peppers were investigated. The viability of the oocysts after treatments was determined using the vital dye propidium iodide. Stained oocysts were counted with a flow cytometer. Chlorine treatments did not significantly affect the viability of the oocysts. Blast freezing affected the viability of 20% of the oocysts. Both microwave heating and blanching affected 93% of oocysts. Combined treatments with chlorine and blast freezing did not affect the viability of the oocysts significantly compared to the control. Combined treatment with chlorine and microwave heating was significantly more effective than microwave heating alone and affected 98.1 % of the oocysts. The data indicate that C. parvum oocysts are sensitive to heat and, to some extent, to freezing temperature but are resistant to chlorine. The results of the survey show the presence of Cryptosporidium and Giardia in irrigation waters and thus a possible health risk associated with the consumption of raw vegetables as those can become contaminated via the irrigation water. The results of the challenge tests indicate that C. parvum oocysts on vegetables are inactivated by blanching and microwave heating but survive blast freezing and exposure to chlorine. Boiling and microwave heating of vegetables should be sufficient to kill C. parvum. On the other hand, ready-to-eat vegetables could be at risk of carrying live C. parvum oocysts as the use of chlorine in washing bath is not expected to inactivate C. parvum oocysts present on vegetables. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Food Science / unrestricted