956 resultados para Agua - Estações de tratamento


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The presence of cyanobacterial blooms in reservoirs intended for supply to the population can create public health problems for many species could produce potentially toxic compounds and these are not eliminated in the conventional procedures used in water treatment plants. So even in amounts less than the maximum allowable limit imposed by MS, cyanotoxins can be present in drinking water distributed to the population, creating a chronic exposure. There is little information about the long-term effects of oral exposure to cyanotoxins. This work aimed to show the exposure orally (v.o) of animals to a crude extract of cyanobacteria containing cyanotoxins to evaluate the reproductive performance of pregnant rats and their offspring and fertility of male rats. The presence of microcystins (MCs) in samples collected during the flowering processes in freshwater reservoirs in the Rio Grande do Norte, was analyzed by enzyme immunoassay and its variants have been identified and quantified by chromatographic methods. It was observed that by administration v.o. cyanobacterial extract containing MCs (40, 100 or 250 ng of MCs / kg / day) did not cause systemic toxicity in adult rats or effect on reproductive performance of male and female rats treated. It was also not observed any changes in skeletal study in the offspring of pregnant rats treated with the extract above. Because the solutions used contained MCs in a concentration equal to or greater than the tolerable daily intake for MCs, the results suggest, therefore, that the development of this work contributed to better assess public health risk as the oral exposure to cyanotoxins, increasing thus the credibility of the maximum allowable limit (LMP) of MCs in drinking water distributed to the population of several countries that use the LMP established by WHO in its legislation

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O desenvolvimento das grandes cidades tem gerado um dos maiores desafios ambientais enfrentados na atualidade, que é a gestão eficaz de resíduos sólidos. A grande variedade e quantidade dos resíduos produzidos diariamente, tem tornado a destinação ecologicamente correta e sustentável destes materiais cada vez mais difícil. Dentre os vários resíduos produzidos diariamente destacam-se os lodos oriundos de estações de tratamento de esgotos, denominados de lodos de esgoto, cuja destinação final segura tem sido discutida mundialmente em diversos estudos, tendo em vista que a tendência de geração deste tipo de resíduo tende a crescer com o aumento do saneamento das cidades. Uma forma amplamente difundida nos países desenvolvidos para destinação dos lodos de esgoto é a incineração destes materiais para posterior envio das cinzas geradas neste processo a aterros sanitários. Porém, tem-se estudado formas alternativas de disposição, destacando-se a utilização destas cinzas como adição mineral em concretos e argamassas de cimento Portland. Sabe-se que o desempenho de resíduos de incineração como adição mineral em matrizes cimentícias, depende em grande parte da capacidade de atuação destes materiais como elementos pozolânicos ou como fileres, podendo estas características serem influenciadas pela temperatura de queima ao qual estes resíduos foram submetidos. Neste sentido, verificou-se com esta pesquisa a influência da temperatura empregada na queima dos lodos sépticos no índice de atividade pozolânica (IAP) das cinzas geradas como resíduo deste processo, aqui denominadas de cinzas de lodo séptico (CLS), sendo em seguida, avaliadas as implicações técnicas e microestruturais da utilização deste resíduo em teores de 10%, 20% e 30% como adição mineral em concretos de cimento Portland. Os resultados obtidos demonstraram não haver alterações significativas no IAP das CLS em decorrência da temperatura utilizada durante o processo de queima dos lodos de esgoto. Além disso, verificou-se que embora a utilização das CLS tenham provocado diminuição da trabalhabilidade dos concretos para todos os teores de incorporação, estas melhoraram a resistência mecânica à compressão, o índice de vazios, a absorção de água e o comportamento microestrutural dos concretos contendo 10% e 20% de resíduo

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This work aims to determine a better methodology to help predicting some operational parameters to a new design of mixer-settler on treating wastewater produced by petroleum industry, called MDIF (Misturador-Decantador à Inversão de Fases/ Mixer-Settler based on Phase Inversion MSPI). The data from this research were obtained from the wastewater treatment unit, called MSPI-TU, installed on a wastewater treatment plant (WTP) of PETROBRAS/UO-RNCE. The importance in determining the better methodology to predict the results of separation and extraction efficiency of the equipment, contributes significantly to determine the optimum operating variables for the control of the unit. The study was based on a comparison among the experimental efficiency (E) obtained by operating MSPI-TU, the efficiency obtained by experimental design equation (Eplan) from the software Statistica Experimental Design® (version 7.0), and the other obtained from a modeling equation based on a dimensional analysis (Ecalc). The results shows that the experimental design equation gives a good prediction of the unit efficiencies with better data reliability, regarding to the condition before a run operation. The average deviation between the proposed by statistic planning model equation and experimental data was 0.13%. On the other hand, the efficiency calculated by the equation which represents the dimensional analysis, may result on important relative deviations (up 70%). Thus, the experimental design is confirmed as a reliable tool, with regard the experimental data processing of the MSPI-TU

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In the urban areas of the cities a larger problem of destiny of effluents of the treatment stations is verified due to the junction of the sewages in great volumes. This way the hidroponic cultive becomes important, for your intensive characteristic, as alternative of reuse. This work presents as objective the improvement of the relation hidric-nutritious of the hidroponic cultive of green forage (FVH) using treaty sewage. The production of forage was with corn (Zea mays L.), using double hybrid AG1051, in the experimental field of the Federal University of Rio Grande do Norte (UFRN), in the city of Natal-RN-Brazil. The treated effluent essentially domestic had origin of anaerobic reactor, type decant-digester of two cameras in series followed by anaerobic filters drowned. The hidroponic experimental system was composed of 08 stonemasons, with limited contours for masonry of drained ceramic brick, measuring each one 2,5 meters in length for 1,0 meter of width, with inclination of 4% (m/m) in the longitudinal sense, leveled carefully, in way to not to allow preferential roads in the flow. These dimensions, the useful area of Isow was of 2 square meters. The stonemasons of cultive were waterproof (found and lateral) with plastic canvas of 200 micres of thickness, in the white color. Controlled the entrance and exit of the effluente in the stonemasons, with cycles of 12,68 minutes, it being water of 1,18 minutes. The treatments were constituted of: T1 - 24 hours/day under it waters with flow of 2 L/min; T2 - 12 hours/day under waters with flow of 4 L/min; T3 - 12 hours/day under waters with flow of 2 L/min; and T4 - 16 hours/day under waters with flow of 3 L/min. There were evaluations of the evapotranspirometric demand, of hidroponic system affluent and effluent seeking to characterize and to monitor physical-chemical parameters as: pH, temperature, Electric Conductivity and Fecal Coliforms. This last one was analyzed to the 11 days after isow (DAS) and to the 14 DAS. The others were analyzed daily. I sow it was accomplished in the dates of February 21, 2007, first experiment, and April 10, 2007, second experiment. The density of Isow was of 2 kg of seeds, germinated before 48 hours, for square meter of stonemason. The statistic delineament was it casual entirely with two repetitions, in two experiments. It was applied Tukey test of average to five percent of probability. The cultivation cycle was of 14 DAS with evapotranspirometric demand maximum, reached by T1, of 67,44 mm/day. The analyzed parameters, as mass of green matter - Kg, productivity-Kg/m2 and reason of production of seed FVH/Kg used in Isow, the best result was presented by T1, obtaining value of up to 19,01 Kg/m2 of cultive. Without significant difference, the T4 presented greats values with 16 hours under cycle of water. The Treatments 2 and 3 with 12 hours under cycle of water, they obtained inferior results to the other Treatments. As treatment system, came efficient in the reduction of the salinity. T1 obtained reduction medium maxim of 62,5%, to the 7 DAS, in the amount of salts that enter in the system in they are absorbed in the cultivation. The cultivation FVH acted reducing the microbiologic load. Significant percentile of reduction they were reached, with up to 90,23% of reduction of Units of Colonies (UFC), constituting, like this, the Hidroponic System as good alternative of treatment of effluents of Reactors of high Efficiency

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The struvite precipitation in wastewater treatments plants offer advantages to obtaining a economically viable product, containing phosphorus, nitrogen and magnesium, in a bioavailable conditions to plants. The precipitation process requires ideal conditions, but all of these aspects are difficult to obtain and may result in resistance to collect crystals during the sedimentation process. Therefore, instead find the best conditions for precipitation, we propose the dissolved air flotation as another method to retrieve the crystals. The application of dissolved air flotation method to promote separation of struvite crystals from sewage supernatant, was evaluated in a precipitation-flotation reactor (flotatest) and were compared with the precipitation-sedimentation assays (jar test). Finally, were observed that the dissolved air flotation process was as feasible as sedimentation to promote struvite crystals separation, and the pH are the most influencer factor for an efficient separation

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The aim of this study is to characterize and evaluate the Macro System of Regional Water Distribution Natal North (RNN) and Southern Regional Natal (RNS), covering 35% and 65% respectively of the Natal-RN City. The terms of the quality and quantity of water (surface and groundwater) were also evaluated in order to adjust the parameters that contribute to proper distribution and control in water reserves. The methodology of the work took place from collecting volumetric data of production capacity and distribution of the two treatment plants for Regional as well as the flow rates of wells. Yet the quantitative capacity of reservation, distribution and consumption of the main reservoirs, population numbers and consumption of members neighborhoods were collected. Data were tabulated and used in computational simulator EPANET to diagnose possible through the water balance, the offers and demands on the water supply system in the neighborhoods of the capital, linking them to specific distribution points. We also evaluated the wells in the levels of nitrate in water consumed. As a result it was found that some neighborhoods in the South Regional Natal, was ranked as critical supply situation: City of Hope, Lagoa Nova and Nova Descoberta, where demand exceeds supply. While in most Northern Regional Natal present deficiency in the supply system as: Lagoa Azul, the Parque dos Coqueiros, igapó, Amarante and Salinas. The rates of nitrate in the city were significant, but manageable with corrective and preventive measures. The averages were 12 mg /l-N in Candelária, 10 mg/l-N in Lagoa Nova, 9 mg/l-N in Satelite, 20 mg/l-N in Gramore and 15 mg/l-N in N. Sra. Apresentação. Therefore proper distribution of water abstracted and implementation of quality control ensures the supply required by the system, associated with preservation of Water Resources of the Metropolitan Region of Natal

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Waste stabilization ponds are the main technology in use for domestic sewage treatment in Rio Grande do Norte State (RN), northeast Brazil. The are around 80 systems, constructed mainly by municipal city halls, being series comprised by a primary facultative pond followed by two maturation ponds the most used configuration. Due to problems related with the production and destination of sludge and generation of bad odors, the designers have avoided the use of anaerobic lagoons. The majority of systems are rarely monitored to verify their efficiencies and to get new project parameters for future designing. This work has as purpose to make a diagnosis of efficiency of three series of waste stabilization pond series (WSPS) of Jardim Lola 1, Jardim Lola 2 and Beira Rio, located in the North Zone of the city of the Natal/RN, treating domestic raw sewage, on the removal of organic matter and thermotolerant coliform, comparing the operational conditions of the systems this inside of the bands foreseen in the project, through parameters BOD5, QOD, thermotolerant coliforms, dissolved oxygen, pH, temperature, ammoniac nitrogen, total and suspended solids. The work was carried through in the WSPS, all constituted by a primary facultative pond followed by two maturation ponds. Socioeconomic characteristics of population are predominantly low and all the plants are very near of the contributing basins. The series were monitored from of May the November of 2002, totalizing 20 collections of grab samples of raw sewage and ponds effluents between 8:00 and 9:50 h. The main aspect to be detached by the results was the great concentration of organic matter (BOD and COD) and microorganisms the raw sewage which were around two times more concentrated than those values foreseen one in project. Considering all series the highest removals of organic matter were observed in system Beira Rio (84 and 78% of BOD and COD, respectively), which presented high hydraulic detention time (TDH = 89 days). On the other hand, Jardim Lola 1 and Jardim Lola 2 presented a much lower values of HDT (36 days and 18 days respectively) and their removals of BOD and COD were the same (76% and 60%, respectively). The Beira Rio WSPS, was the most efficient verified in relation to solids and ammonia, proving the great influence of the operational variables such as HDT and applied surface organic loadings on the performance of pond series. Although the treatment plants have reached efficiencies of thermotolerant coliforms around 99,999%, the concentrations in the final effluent can be considered very high for launching in aquatic bodies, particularly those produced by Jardim Lola 1 and Jardim Lola 2 series

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A utilização de recursos naturais e a necessidade de recuperação de áreas degradadas têm assumido importância global, sendo que a estimativa de custos garante a viabilidade econômica, para implantação de projetos de conservação ou recuperação. Foram estimados os custos para implantação de um hectare da espécie arbórea Gonçalo-Alves (Astonium fraxinifolium Schott), com adubação verde, em Latossolo Vermelho degradado, como se segue: Gonçalo-Alves + Feijão-de-porco; Gonçalo-Alves + crotalária; Gonçalo-Alves + fórmula NPK (04-14-08); e Gonçalo-Alves + braquiária + lodo. A estimativa do custo de implantação de Gonçalo-Alves, para a região leste do Estado do Mato Grosso do Sul, variou entre R$ 2.829,13 e R$ 3.872,21. O tratamento com braquiária + lodo de esgoto foi o mais econômico, considerando-se um período de cinco anos, além dos benefícios ambientais relacionados ao descarte viável deste resíduo, por estações de tratamento de esgoto.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)