1000 resultados para poluição das águas
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Geophysics studies in areas impacted by petroleum derivatives describe abnormalities of both low and high electrical resistivity (the opposite of electrical conductivity), confirmed as contaminant phase by chemical analysis: this contradiction can be explained by degrading processes that naturally occur and create sub products that can change the environment conductivity. Monitoring the variation of the parameters mentioned serves as a comparative basis to the variation in geoelectrical parameters, which identified the correlation between the same contaminant parameters and the difference between their behavior studied apart, as well as its relations with the biodegradation process. The results are applied to the fuel distribution and storage sectors, leading to the diagnosis and monitoring of possible groundwater contamination scenarios, and the knowledge of the area exposure time to the contaminant, besides the better remediation alternative and impacts control. Among some conclusions, the most significant are the decrease in conductivity over time, so as the increase in Eh value in the gasoline contaminated tank, as well as the decrease in the pH value in the second tank with ethanol, which can be attributed to its degradation. Comparing the variations in both tanks, it is evident that Eh, pH and electrical conductivity do not behave temporally in a similar way, although some correlations between Eh and pH can be related.
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The success in implementing an embryo transfer program derives from many factors. The embryo recovery rate is one of the most important factors, and allows the transfer to the recipient mare. This rate comes from a group of elements such as donor´s characteristics, collection date, reproductive management, semen quality, technician skill. Mainly because of the great importance of this direct interference on the results of an embryo recovery program, this study aimed to review the factors involved in embryo recovery rates in donor mares during an embryo transfer, suggesting some ways of improving these results
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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To verify the levels of concentration of some heavy metals in fishes from Sorocaba river (São Paulo, Brazil) and evaluate if this contamination offers health risks to the fishermen, 63 samples of fishes collected from four points along the river were studied for cadmium, lead, chromium, nickel and mercury, with emphasis in this last, since it is the most toxic and most probable as a fish contaminant. Analyzing muscle samples by cold vapor atomic absorption spectrometry it was shown that the fishes are not contaminated. None of the five metals studied were present in prohibitive level and the fishes could be judged secure for human consume. It was also analyzed data from four years of cadmium, lead, chromium, nickel and mercury monitoring made by CETESB, from 1997 to 2000, in water from the main rivers of the State of São Paulo. The study pointed out that the majority of the monitored rivers still present contamination by those metals in a level that requires an improvement of the pollution control actions.
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Cassava wastewater, generated during cassava processing, is a highly polluting and toxic waste. This study aimed to assess the relationship of cassava treatment efficiency in two aerobic sequencing batch reactors, cylindrical plastics (31cm height x 9cm diameter), with 2.0 liters capacity and 1.5 liters of work volume, a ratio of diameter and height of the liquid 1:2.5, with a running time of 24 hours and stoppage aeration for 16 hours with average feed of 2,500 and 6,000 mg COD. L -1. COD, pH, SVI and F/M were analyzed. The results obtained in the two reactors showed an average reduction of 94.1% and 76.8% organic content, respectively; pH values showed a rising in the output pH values compared to entry ones; SVI values obtained: 54.1 mL/g, 99.3 mL/g, respectively in a F/M ratio values worked out of 0.4 d-1 and 1,1 d-1 , respectively. The results demonstrated that the process has generated considerable saving in energy consumption compared to traditional continuous systems, was efficient and did not affect the efficiency overly of the reactor.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Medicina Veterinária - FMVZ
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Pós-graduação em Engenharia Civil e Ambiental - FEB
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Pós-graduação em Geociências e Meio Ambiente - IGCE