226 methanol and water extracts representing 74 mainly native plant species found in Amazonas State, Brazil, were tested at a standard concentration of 500 μg/mL for lethality towards larvae of the brine shrimp species Artemia franciscana.
Ethanol, methanol and water extracts representing mostly native plant species found in the Amazon region were prepared, respectively, by maceration, continuous liquid-solid extraction and infusion, followed by evaporation and freeze-drying. The freeze-dried extracts were tested for lethality toward Aedes aegypti larvae at test concentrations of 500 µg / mL. In general, methanol extracts exhibited the greatest larvicidal activity. The following 7 methanol extracts of (the parts of) the indicated plant species were the most active, resulting in 100 % mortality in A. aegypti larvae: Tapura amazonica Poepp. KEY WORDS
A capacidade das plantas em tolerar e absorver quantidades elevadas de metais pesados é usada como uma tecnologia promissora para limpeza de resíduos perigosos em ambientes altamente contaminados. O desempenho da macrófita L. aequinoctialis em absorver metais pesados foi estudado durante sua floração em dois períodos de amostragem diferentes. Ability of Lemna aequinoctialis for removing heavy metals from wastewater ABSTRACTPlant ability for tolerating and accumulating high amount of heavy metal is used as a promissory technology for removing contaminants from highly polluted environments. The ability of the macrophyte L. aequinoctialis to remove heavy metal was studied in two different sampling times during its flowering. Samples of plant tissue L. aequinoctialis and water were collected for 800 hours at 48 hour intervals. Concentrations of Ni, Cu, Co, Cr, Mn, Zn, and Fe present in L. aequinoctialis and water were determined by flame atomic absorption spectrometry (FAAS). Data were subjected to the techniques of principal components analysis (PCA), hierarchical cluster analysis (HCA) and boxplot. We found that rhizofiltration of L. aequinoctialis removes high amount of heavy metal in this order: Cr >Ni>Cu> Fe > Zn >Mn. Only significant changes in chemical composition of the water, pH and electrical conductivity alter the absorption capacity of L. aequinoctialis.
RESUMOO uso de energias renováveis aliadas à preservação do meio ambiente tem despertado interesse cada vez maior em nível nacional e internacional principalmente a utilização do biodiesel em substituição ao diesel de petróleo. Sua utilização traz uma série de vantagens sociais, econômicas e ambientais. Nos últimos anos, houve no Brasil um aumento nas pesquisas sobre o biodiesel. A lei brasileira nº 11.097 de 2005 dispõe sobre a introdução do biodiesel na matriz energética brasileira, misturado ao óleo diesel em um percentual mínimo obrigatório de 2%, com aumento na adição para 5% até 2012. Contudo, essa adição só é possível se o biodiesel estiver dentro dos padrões de qualidade exigidos. Diante disto, neste trabalho foram preparadas misturas de biodiesel adicionado ao diesel interior, nas proporções 2, 5, 10 e 20% (v/v), sendo posteriormente caracterizados a partir da determinação dos parâmetros físico-químicos citados na Resolução da Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP), visando avaliar se as misturas estão em conformidade com a norma. De acordo com os resultados concluiu-se que, tanto o biodiesel quanto suas misturas binárias (B2 a B20) encontram-se dentro dos padrões de qualidade estabelecido pela ANP. PALAVRAS-CHAVE:Biodiesel, Óleo diesel, Parâmetros físico-químicos. Physical chemical characterization of binary mixtures of biodiesel and diesel commercialized in Amazonas ABSTRACTThe use of renewable energies allied to the preservation of the environment has awakening more and more interest on the national and international level, especially the utilization of biodiesel in substitution of petroleum diesel. Its use brings a series of social, economical and environmental advantages. In the last few years, there has been an increase in biodiesel research in Brazil. The Brasilian law no. 11.097 of 2005 proposes the introduction of biodiesel in the Brazilian energetic matrix, mixing it with diesel oil at an obligatory percentile minimum of 2%, with an increase of 5% in the addition, until 2012. However, the addition is only permitted if the biodiesel is within the quality patterns demanded. Before this, mixtures of biodiesel added to interior diesel were prepared, in proportions of 2, 5, 10 and 20% (v/v), which were later characterized, as of the physical chemical parameters determined in the Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) Resolution for evaluating mixtures in accordance with the norm. The results show that, biodiesel as well as their binary mixtures (B2 to B20) are within the quality patterns established by the ANP.
Resumo -A avaliação da qualidade da água utilizada para a irrigação no meio agrícola é relevante tanto para o meio ambiente, quanto para a saúde humana. O uso contínuo de água contaminada acarreta poluição ao solo e às culturas cultivadas, transmitindo doenças por meio do consumo de hortaliças contaminadas. Desse modo, objetivou-se com esse trabalho avaliar a qualidade da água de irrigação de três corpos hídricos: poço, cacimba e igarapé, utilizada na Comunidade Agrícola Nova Esperança, localizada entre uma área urbana periférica e uma floresta nativa na cidade de Manaus -AM. Foram avaliados os metais potencialmente tóxicos (MPT): Cd, Cu, Co, Fe, Ni, Mn, Pb e Zn, utilizando espectrometria de absorção atômica por chama e medidas bacteriológicas (coliformes totais e fecais) pelo método de membrana filtrante. Os resultados indicam altos índices de coliformes totais e fecais, 89,3% nas amostras de água coletadas nos três corpos hídricos: poço, cacimba e igarapé da área de estudo, assim como elevados níveis de MPT, com destaque para Cd e Pb extremamente tóxicos. Os testes estatísticos mostraram que há influência do período sazonal sobre as concentrações médias dos MPT e que não existem diferenças significativas destes contaminantes, entre os diferentes corpos hídricos, durante todo o período estudado. Palavras-chaves -Coliformes. Contaminação. Metais pesados.Abstract -The evaluation of the quality of the water used for irrigation in agriculture is of great importance for the environment and human health. The continuous use of contaminated water causes pollution to soil and cultivated crops, causing various diseases associated with consumption of contaminated vegetables. Thus, the objective of this study was to evaluate the quality of irrigation water of three water bodies: artesian wells, cacimbas (kind of graves that collect water from swampy lands) and streams, used in the Nova Esperança Agricultural Community, located between a peripheral urban area and a native forest in Manaus -AM. Potentially toxic metals (PTM): Cd, Cu, Co, Fe, Ni, Mn and Zn were evaluated using atomic absorption spectrometry by flame and bacteriological analyses (total and faecal coliforms) by filter membrane method. The results showed high levels of total and faecal coliforms, 89,3% in water samples collected in the three water bodies, as well as high levels of TPM, especially Cd and Pb extremely toxic. Statistical tests showed the influence of the seasonal period on the average concentrations of the PTM and there is not meaning difference of these contaminants on the different water bodies during the period of this study.
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