Mestrado em Engenharia Ambiental e Sanitária (EEC)
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Navegando Mestrado em Engenharia Ambiental e Sanitária (EEC) por Por Orientador "Hoffmann, Nora Katia Saavedra del Aguila"
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Item Avaliação da qualidade da água e do sedimento no reservatório de abastecimento público do ribeirão João Leite-GO(Universidade Federal de Goiás, 2017-08-25) Arantes, Andréia Gomes dos Santos; Hoffmann, Nora Katia Saavedra del Aguila; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4709330Z7; Cuba, Renata Medici Frayne; Carrijo, Ivaltemir BarrosThe reservoir João Leite is located upstream of the city of Goiânia (Goiás-Brazil), and has as its sole objective the public water supply to the city of Goiânia and conurbated areas. In view of the constant deterioration of the water resources along the drainage basin, it is necessary to include the sediment quality assessment in order to complement the environmental monitoring protocols. The objective of this research was to evaluate the water and sediment quality of the João Leite reservoir in the rainy season and in the dry season, with the purpose of assisting in the process of water purification that will be distributed to the population, together with other processes operation and maintenance of a water treatment plant. Water and sediment samples were collected at five sampling points during rainy and dry periods during the year 2016. In the sediments were determined grain size, pH, CTC, organic matter, oxygen consumed, total nitrogen, macronutrients, micronutrients and pesticides. The pH, electrical conductivity, water temperature, turbidity and dissolved oxygen were determined on the surface, medium and bottom, and the concentrations of ammonia, nitrate, nitrite, total phosphorus, TOC and pesticides. Also, acute toxicity tests were performed with lettuce seeds (Lactuca sativa L.) for the sediment samples. Concentrations of atrazine, ranging from 0.166 to 0.304 μg.L-1 and from trifluralin (0.200 μg.L-1) were identified in the water samples collected during the dry season. All values found remained within the maximum values allowed by Conama Resolution 357/2005 for Class 2 fresh waters. High concentrations of total iron (190.7 and 196.5 mg.kg-1 in drought and of manganese (159.7 and 177.2 mg.kg-1 in drought and from 163 to 179.5 mg.kg-1 in the rainy season), which may alter the characteristics of water during events of destratification. The acute toxicity tests indicated that, with the bottom sediments of the João Leite reservoir sampled in the regions closest to the bus (P2 and P3), the seeds presented reduced growth, both the root and the hypocotyl. However, the presence of toxic substances has not been identified in the analysis of pesticides capable of causing harmful effects.Item Recuperação de microalgas em lagoa de maturação por meio de floculação alcalina(Universidade Federal de Goiás, 2019-10-11) Marinho, Paulo Henrique Oliveira; Hoffmann, Nora Katia Saavedra del Aguila; http://lattes.cnpq.br/1362954040022741; Hoffman, Nora Katia Saavedra del Aguila; Teran, Francisco Javier Cuba; Rios, Fernanda PoschThe biomass produced by microalgae can be used to various ends. Given the cost demanded to its cultivation and biomass harvest, the conventional liquid medium separation mechanisms are not viable. In face of that, alkaline flocculation, with the cultivation in wastewater, has the potential to overcome the limitations on energy and nutritional costs. The present study aimed to test the alkaline flocculation followed by sedimentation in maturation ponds from ETE Goianira (in the city of Goianira, Goiás), as well as the lipid content obtained from the generated sediment. Three different bases were used to induce pH to the desired value (NaOH, CaCO3 and Ca(OH)2) in five pH ranges (8, 9, 10, 11 and 12). Ca(OH)2 presented the best efficiencies, reaching an average >70%, although the use of this base implicated on a higher sediment volume, which may be a limiting factor. The NaOH showed efficiency >40%, producing smaller amount of sludge and, consequently, higher lipid/sedimentation ratio. During the tests, NaCO3 was not feasible to induction of alkaline flocculation. In general, the achieved efficiencies were consistent with what is presented in the literature. The efficiencies were below trials conducted with cultivation of isolated genera or species, or in a controlled environment. A total lipid of 125 and 286 mg.L-1 were extracted in the use of NaOH and Ca(OH)2, respectively. There are evidences that the presence of other microorganisms may interfere with the achieved efficiency, reducing the efficiency on the microalgae biomass recovery, but without making alkaline flocculation unfeasible. The alkaline flocculation could be used to biomass recovery in maturation pond, with margin for efficiency improvement. The method can be used as a treatment, since it seems to reduce the concentration of orthophosphates, calcium and magnesium, microalgae and other negatively charged microorganisms.Item Decaimento da concentração de cloro residual livre nas redes de abastecimento de água(Universidade Federal de Goiás, 2018-07-13) Oliveira, Luciano de; Hoffmann, Nora Katia Saavedra del Aguila; http://lattes.cnpq.br/1447294667795452; Hoffman, Nora Katia Saavedra del Aguila; Teran, Francisco Javier Cuba; Formiga, Klebber Teodomiro Martins; Santos, Felipe Corrêa Veloso dos; Pfeiffer, Simone CostaThe chlorination process is the most used to promote disinfection of water intended for human consumption. During the course of chlorinated water in the supply systems, the concentration of free residual chlorine (FRC), whose reaction rate depends on the characteristics of the natural water, occurs. In this work, we studied the decay of the FRC concentration related to the reactions in the liquid mass in two types of water, of subterranean and superficial origin, with different concentrations of organic matter, with the perspective of the influence of the water travel time, dependent on consumption scenarios in real distribution networks, whose supply modules are characterized by low population density and that operate under the initial demand conditions predicted in the projects. The effect of temperature and total organic carbon on the values of mass decay kinetic constants (k b ), used in mathematical models that simulate water quality, was considered. The results showed that the variation of the kb values is directly proportional to the water temperature and the TOC. For initial concentrations close to 1.00 mg.L -1 , the values of the kinetic constants for waters from surface water sources maintained in the temperature ranges of 20 to 21 °C and 30 to 31 °C were respectively 0.0888 day -1 and 0.1200 day -1 for samples collected at the ETA filter output of the DAIAsystem and TOC value of 0.4798 mg.L -1 and equal to and 0.1680 day -1 and 0.3024 day -1 for the samples collected at the filter outputs of the Piancó and TOC system ETA of 0.8750 mg.L - . In samples of groundwater with TOC of 0.1740 mg.L -1 , maintained at the same temperature 1 ranges, the kinetic coefficients were 0.0264 day -1 and 0.0480 day -1 , respectively. Experiments for temperature between 30 and 31 °C and near test duration showed a significant difference in chlorine decay behavior in filtered water samples collected at conventional treatment plants, which showed a residual chlorine loss percentage of 64.81% in relation to the initial concentration of 1.08 mg.L -1 of disinfectant (ETA DAIA) and 33.65% in relation to the initial concentration of 1.05 mg.L -1 of disinfectant (ETA Piancó). Raw water samples from the underground spring lost 14.33% of the initial concentration of 1.04 mg.L -1 . The travel times for the most critical nodes and the minimum disinfectant concentrations at the entrance of the supply modules to comply with the legislation were 40 hours and 0.27-0.28 mg.L -1 for the distribution networks of the condominium Valley of the Birds and 144 hours and 0.30-0.36 mg.L -1 for the condominium Terras Alphaville.