Avaliação ecotoxicológica preliminar das águas das bacias hidrográficas dos rios Tarumã, São Raimundo e Educandos/ Preliminary evaluation of the toxicity in water of the Tarumã, São Raimundo and Educandos basins
Resumo em português As Bacias hidrográficas dos riosTarumã, São Raimundo e Educandos e seus afluentes estão sendo impactados, devido as influências antrópicas. Neste estudo foi realizada uma avaliação da toxicidade das águas destes ecossistemas, através de testes de toxicidade aguda com Daphnia similis e análises físico-químicas. Os resultados obtidos demostraram um maior efeito deletério sobre D. similis, nas amostras da microbacia Tarumã. Resumo em inglês The Tarumã, São Raimundo and Educandos basins, and their tributaries, are impacted by antropic influence. This study tried to evaluate the water toxicity of the hydrographic basins, through acute toxicity bioassay using Daphnia similis as test-organism and physical and chemical analysis. The results showed that, of the three basins, the water from Tarumã caused the most deleterious effect on D. similis.
Testes de toxicidade aguda através de bioensaios no extrato solubilizado dos resíduos classe II A - não inertes e classe II B - inertes/ Acute toxicity tests by bioassays applied to the solubilized extracts of solid wastes class II A - non inerts and class II B - inerts
Resumo em português A grande diversidade de substâncias potencialmente tóxicas contribuem para a deterioração do meio ambiente. O objetivo deste trabalho foi propor a utilização de bioensaios, através de testes de toxicidade aguda com Daphnia magna e Vibrio fischeri, como mais um parâmetro a ser analisado no extrato solubilizado dos resíduos que, segundo a NBR 10004/04 fossem classificados como classe II A - não inertes ou classe II B - inertes. Realizaram-se, também, testes de to (mais) xicidade no drenado dos aterros classe II A e II B. Verificou-se que a toxicidade foi constatada nos extratos solubilizados dos 18 resíduos analisados e que, apenas três das amostras estariam próprias para lançamento, ou seja os resíduos 04, 14 e 15. Já, a toxicidade encontrada no drenado dos aterros, ficou muito superior do que a toxicidade de cada extrato solubilizado analisado separadamente. Resumo em inglês A great diversity of substances potencially toxic contributes to the deterioration of the environment. The aim of this research was to propose the use of bioassays using Daphnia magna and Vibrio fischeri, as another parameter to be analyzed in the solubilized extraction of waste according to NBR 10004/04 and classified as class II A - non inerts or class II B - inerts. Besides, another test was performed to measure the level of toxicity in the drainage of the landfill cla (mais) ss II A and II B. It was verified that the toxicity found in the solubilized extracts of the 18 wastes analysed.Only 3 wastes (04, 14 and 15) were within the emission limits. On the other hand the toxicity found in the drainage of the landfill, from which all the samples came from, was much higher than the individual one.
Resumo em inglês Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD) and chemical (COD) oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD) showed that the biodegradability o (mais) f the wastewater was significantly increased; furthermore, Fe2+ ions liberated by the electrodes cause microorganisms to die and, when oxidised to Fe3+, contribute for the flocculation and sedimentation of solid residues.
Constituintes químicos e efeito ecotoxicológico do óleo volátil de folhas de Eucalyptus urograndis (Mirtaceae)/ Chemical constituents and ecotoxicological effect of the volatile oil from leaves of eucalyptus urograndis (Mirtaceae)
Resumo em inglês The volatile oil from the leaves of E. urograndis was analyzed by GC and GC-MS. It was identified 10 compounds in which, orto-cimene (41.4%) and 1,8-cineol (25.8%) were the main constituents. The induction of deleterious effect to aquatic organisms due to the presence of volatile oil lixiviated from E. urograndis leaves was studied using Daphnia laevis and D. similis as bioindicators. Through the results of toxicological tests it was possible to show that the litterbag of (mais) E. urograndis represents a risk factor for the aquatic ecosystem of lakes and rivers that are in the surrounding area of large scale Eucalyptus plantations. The method can be used for monitor the quality of these types of aquatic environments.
Estudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos: contribuições para a remediação de sítios contaminados/ Study of lead behaviour in Brazillian latosoils treated with phosphates: contributions to the remediation of contaminated sites
Resumo em inglês Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecoto (mais) xicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.