Thesis (M.S.)--Oregon State University, 2011. / Printout. Includes bibliographical references (leaves 69-74). Also available on the World Wide Web.

Thesis (M.S.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (viewed on Sept. 19, 2006). Thesis advisor: Joanne Logan. Vita. Includes bibliographical references.

Thesis (M.A.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A Ãgua à um recurso essencial e atualmente gestores ambientais do mundo inteiro chamam a atenÃÃo para o problema da escassez de Ãgua limpa. Tal escassez hÃdrica à ainda mais forte nas regiÃes Ãridas e semiÃridas do globo. No nordeste brasileiro, e em particular, no semiÃrido, uma sÃrie de fatores o torna particular. A irregularidade pluviomÃtrica, sua mà distribuiÃÃo no tempo e no espaÃo, a elevada taxa de evaporaÃÃo/evapotranspiraÃÃo e as altas temperaturas sÃo traÃos marcantes do ambiente, diferenciando-o de outros locais do mundo. Assim, o gerenciamento de lagos visando à proteÃÃo e manutenÃÃo de uma boa qualidade da Ãgua, a vida aquÃtica e os outros usos deve ser abordado de maneira em que se leve em consideraÃÃo as caracterÃsticas regionais. O objetivo deste trabalho foi identificar o impacto das variÃveis meteorolÃgicas na qualidade da Ãgua, analisando a influÃncia do processo de estratificaÃÃo tÃrmica e de mistura; e com isso, propor um sistema de monitoramento e modelagem. O reservatÃrio estudado foi o Pereira de Miranda (Pentecoste â CE), onde um Ãnico ponto de amostragem foi estabelecido, visando sua caracterizaÃÃo vertical. ApÃs a seleÃÃo dos principais parÃmetros de qualidade da Ãgua e dos fatores meteorolÃgicos mais relevantes, foi traÃada uma discussÃo qualitativa e uma anÃlise da variabilidade tÃrmica da coluna dâÃgua. Notou-se pelos perfis verticais de temperatura e dos fluxos de calor obtidos uma clara formaÃÃo de termoclinas, e sua destruiÃÃo ao longo do dia, fato associado à radiaÃÃo solar e os fortes ventos que impÃs significativa variaÃÃo nos valores de oxigÃnio dissolvido. De posse de todas as variÃveis pesquisadas foi proposto um sistema de monitoramento como componente chave da proteÃÃo ambiental, com base no Ciclo de Deming. Esta rotina, acoplado a um sistema de modelagem da qualidade da Ãgua, aperfeiÃoa a avaliaÃÃo e a gestÃo dos ecossistemas. Assim, alÃm de exercer o controle das atividades de monitoramento da qualidade da Ãgua, poderà ser utilizado de forma contÃnua para o gerenciamento dos recursos hÃdricos. / Water is an essential natural resource in the planet and nowadays environmental managers around the world concern to the scarcity of clean water. This scarcity is even greater in arid and semiarid regions of the globe. In northeastern Brazil, and particularly in the semiarid region, a number of factors make it particular. The irregularity of rainfall, its poor distribution in time and space, the high rate of evaporation / evapotranspiration, and high temperatures are characteristics of this environment that differs from other places in the world. Thus, the management of lakes to protect and maintain good water quality, aquatic life and other uses should be analyzed according to regional characteristics. The purporse of this study was to identify the impact of meteorological variables in water quality including the influence of the thermal stratification and mixing, and thus, propose a system for monitoring and modeling. The Pereira de Miranda (Pentecoste-CE) was studied with only one sample point to characterize its vertical profile. After selecting the main parameters of water quality and meteorological factors most relevant, was drawn a qualitative discussion and analysis of thermal variability in the water column. It was observed by the vertical profiles of temperature and heat flux a clear thermocline formation and destruction throughout the day, a fact linked to solar radiation and strong winds that imposed significant variation in levels of dissolved oxygen. In possession of all the variables studied was proposed a monitoring system as a key component of environmental protection, based on the Deming Cycle. This routine, coupled with a modeling system of water quality, improves the assessment and management of ecosystems. Thus, in addition to exerting control over the activities of monitoring of water quality, can be used continuously for the management of water resources.

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Made available in DSpace on 2016-08-10T10:55:44Z (GMT). No. of bitstreams: 1 Aurelio de Melo Barbosa.pdf: 8372928 bytes, checksum: 34ed59e6bd218f99a1d12f2d2abdaa9e (MD5) Previous issue date: 2009-03-30 / Water, essential for life, has a direct influence on health, quality of life and development of mankind. However, due to natural and human causes, water may suffer contamination from various species, especially for chemical elements. Thus, this paper appears the results of a study of multi-elemental chemical analysis of samples of treated water collected in Water Treatment Plants of twenty-two cities of South Region of Goias State. It was also exposes data on sanitation and hospital morbidity and mortality of the study area. It was found two geochemical associations (SO4-Cl-Zn-Mn and Ca-Sr-Mg), that were presented in maps of distribution of each element geochemistry. Also it was found anomalous concentrations above the maximum permitted values of nitrate in samples of Quirinópolis and Morrinhos, and lead in the sample of Cromínia, with possible impact on the morbidity and mortality of these municipalities. / A água, essencial para a vida, tem influência direta sobre a saúde, qualidade de vida e desenvolvimento do ser humano. Entretanto, devido a causas naturais e antrópicas, a água pode sofrer contaminação de várias espécies, especialmente por elementos químicos. Assim, realizou-se um estudo de análise química multielementar de amostras de água tratada colhidas em Estações de Tratamento de Água de vinte e dois municípios da Mesorregião Sul Goiano. Também foram coletados dados sobre saneamento básico e morbidade hospitalar e mortalidade da área de estudo. Como resultado foram encontradas duas associações geoquímicas (Cl-Zn-SO4-Mn e Ca-Sr-Mg), sendo apresentados os mapas de distribuição geoquímica de cada elemento. Também descobriu-se concentrações anômalas, acima dos Valores Máximos Permitidos, de nitrato nas amostras de Quirinópolis e Morrinhos, e de chumbo na amostra de Cromínia, com possível impacto sobre a morbimortalidade dos referidos municípios.

Water quality from surface sources is fast deteriorating due to pollution from organic compounds. Among the organic compounds are chlorophenols, which are described as priority pollutants because of their detrimental effects. One way of removing them from water is by using membranes. However direct removal of chlorophenols using membranes is limited due to the inherent problem of membrane fouling. The thesis describes fabrication of thin film composite membranes modified with Ag-TiO2 and Ag-ZnO for enhancing filtration properties of the membranes for removal of 2-CP and 2,4-DCP and improving the antifouling properties of the modified membranes. Chlorophenols, 2- CP, 2,4-DCP and 2, 4, 6-TCP were determined from Vaal and Klip River using SPE- HLPC method. The SPE - HPLC method was validated by determining breakthrough volume, repeatability, reproducibility, linearity, MDL and LOQ. Nanoparticles (NPs), Ag, ZnO and TiO2 and nanocomposites (NCs), Ag-TiO2 and Ag-ZnO were synthesized using precipitation method and chemical reduction for Ag. The NPs and NCs were characterised using UV-Vis, FTIR, XRD, SEM and EDX. The synthesised NPs and NCS were evaluated for photocatalytic degradation of 2-CP and 2,4-DCP, antimicrobial activity against E.coli. and toxicity against Daphnia magna. Nanocomposites were then embedded into the PA thin film membrane surface using interfacial polymerisation and PES as a support material to produce the antifouling Ag-TiO2/PA-TFC and Ag-ZnO/PA-TFC membranes. The control PATFC membrane was prepared with no added NCs to the membrane. The membranes were characterised using ATR-FTIR, contact angle, SEM and AFM. The performance of the membranes was tested using permeation flux (using pure water and 2-CP / 2,4-DCP solutions as feed) against the neat PA-TFC membrane. Membranes were further tested for rejection of 2- CP and 2, 4 – DCP, antifouling properties and flux recoveries. The stability of the antifouling properties of the membrane was evaluated through silver release test. The performance of the membranes was tested using real water samples from Vaal and Klip Rivers. The SPE-HPLC method was repeatable, reproducible with % RSD less than 5%. Linearity range of (0.1-50 µg/ L) and recoveries of spiked water samples of more than 97% for 2-CP and 2,4-DCP but lower at 64 and 75% for 2.4.6-TCP were achieved. The Ag, TiO2 and ZnO NPs showed characteristic peaks of NPs with UV-Vis. The absorption peaks were all blue shifted due to quantum confinements. The crystalline structures were confirmed as face centred cubic, anatase and hexagonal wurzite for Ag, TiO2 and ZnO respectively. The morphology as observed from SEM showed spherically shaped nanoparticles with average sizes of 68.25 ± 4.7 and 50.92 ± 3.39 nm for Ag and TiO2 respectively. The ZnO NPs were rod -like shaped with average length = 603 nm ± 50.4 and a width = 82.92 ± 5. 40nm. Successful incorporation of silver into the TiO2 and ZnO structures was confirmed by elemental analysis, EDX. From SEM images, silver particles were distributed around TiO2 particles and ZnO rods. The presence of silver showed a remarkable improvement in photodegradation of 2-CP and 2,4-DCP from less than 40% to 86% with 2, 4- DCP. Silver modified TiO2 and ZnO showed antibacterial activity against E.coli. with minimum concentration of inhibition as low as 1.56 mg/L for both Ag-ZnO (5) and Ag-TiO2 (5). Silver was more toxic against Daphnia magna than Ag-ZnO (5) and AgTiO2 (5). The polyamide layer was confirmed by the presence of the amide I peak at 1650 cm1 and 1670 cm-1 in the Ag-TiO2/ PA-TFC and Ag-ZnO/ PA-TFC membranes. The appearance of NCs particles spread across the surface of the thin layer of the membranes as observed from surface SEM images confirming their incorporation into the PA layer. The presence of the NCs in the membranes improved water flux, water permeation, rejection of 2- CP, and 2,4-DCP, antifouling properties of the membranes and flux recoveries of more than 93 % was achieved. Silver release test revealed that Ag-ZnO/PA-TFC membrane performed better than AgTiO2/PA-TFC membrane because of the steady release of silver, which shows long lasting antifouling properties. When applied to real water samples from Vaal and Klip River, the prepared membranes showed better antifouling properties than the neat PA-TFC membrane

Without a comprehensive understanding of anthropogenic pressures on the water environment, it is difficult to develop effective and efficient strategies to support water management in a proactive way. A broader systems perspective and expanded information systems are therefore essential to aid in systematically exploring interlinks between socioeconomic activities and impaired waters at an appropriate scale. This thesis examined the root causes of human-induced water problems, taking the socioeconomic sector into account and using systems thinking and life cycle thinking as the two main methods. The European DPSIR (Drivers-Pressures-State of the Environment-Impacts-Responses) framework was also used as a basis for discussing two kinds of approaches to water management, namely state/impacts-oriented and pressure-oriented. The results indicate that current water management approaches are mainly state/impacts-oriented. The state/impacts-oriented approach is mainly based on observed pollutants in environmental monitoring and/or on biodiversity changes in ecological monitoring. Employing this approach, the main concern is hydrophysical and biogeochemical changes in the water environment and the end result is reactive responses to combat water problems. As a response, a pressure-oriented approach, derived from a DPR (Drivers-Pressures-Responses) model, was developed to aid in alleviating/avoiding human-induced pressures on the water environment. From a principal perspective, this approach could lead to proactive water-centric policy and decision making and the derivation of pressure-oriented information systems. The underlying principle of the DPR approach is that many root causes of human-induced water problems are closely related to anthroposphere metabolism. An industrial ecology (IE) perspective, based on the principle of mass/material balance, was also introduced to trace water flows in the human-oriented water system and to account for emissions/wastes discharged into the natural water system. This IE-based perspective should be used as part of the basis for developing pressure-oriented monitoring and assessing impacts of human-induced pressures on recipient waters. While demonstrating the use of the pressure-oriented approach, two conceptual frameworks were developed, for water quantity and water quality analysis, respectively. These two frameworks could help motivate decision makers to consider water problems in a broader socioeconomic and environment context. Thus they should be the first step in making a broader systems analysis in any given river basin, regarding setting systems boundary and identifying data availability. In this context, a combined hydrological and administrative boundary is suggested to monitor anthropogenic processes and organise socioeconomic activity statistics. / QC 20120515

Shallow lakes are an important ecological and socio-economic resource. However, the impact of human pressures, both at the lake and catchment scale, has precipitated a decline in the ecological status of many shallow lakes, both in the UK, and throughout Europe. There is now, as direct consequence, unprecedented interest in the assessment and monitoring of ecological status and trajectory in shallow lakes, not least in response to the European Union Water Framework Directive (2000/60/EC). In this context, the spatially-resolving and panoramic data provided by remote sensing platforms may be of immense value in the construction of effective and efficient strategies for the assessment and monitoring of ecological status in shallow lakes and, moreover, in providing new, spatially-explicit, insights into the function of these ecosystems and how they respond to change. This thesis examined the use of remote sensing data for the assessment of (i) phytoplankton abundance and species composition and (ii) aquatic vegetation distribution and ecophysiological status in shallow lakes with a view to establishing the credence of such an approach and its value in limnological research and monitoring activities. High resolution in-situ and airborne remote sensing data was collected during a 2-year sampling campaign in the shallow lakes of the Norfolk Broads. It was demonstrated that semi-empirical algorithms could be formulated and used to provide accurate and robust estimations of the concentration of chlorophyll-a, even in these optically-complex waters. It was further shown that it was possible to differentiate and quantify the abundance of cyanobacteria using the biomarker pigment C-phycocyanin. The subsequent calibration of the imagery obtained from the airborne reconnaissance missions permitted the construction of diurnal and seasonal regional-scale time-series of phytoplankton dynamics in the Norfolk Broads. This approach was able to deliver unique spatial insights into the migratory behaviour of a potentially-toxic cyanobacterial bloom. It was further shown that remote sensing can be used to map the distribution of aquatic plants in shallow lakes, importantly including the extent of submerged vegetation, which is central to the assessment of ecological status. This research theme was subsequently extended in an exploration of the use of remote sensing for assessing the ecophysiological response of wetland plants to nutrient enrichment. It was shown that remote sensing metrics could be constructed for the quantification of plant vigour. The extrapolation of these techniques enabled spatial heterogeneity in the ecophysiological response of Phragmites australis to lake nutrient enrichment to be characterised and assisted the formulation of a mechanistic explanation for the variation in reedswamp performance in these shallow lakes. It is therefore argued that the spatially synoptic data provided by remote sensing has much to offer the assessment, monitoring and policing of ecological status in shallow lakes and, in particular, for facilitating the development of pan-European scale lake surveillance capabilities for the Water Framework Directive (2000/60/EC). It is also suggested that remote sensing can make a valuable contribution to furthering ecological understanding and, most significantly, in enabling ecosystem processes and functions to be examined at the lake-scale.

Thesis (M. Phil.)--University of Hong Kong, 1993.