This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

This work focused on preparing and characterizing Brazilian bentonite clay through the use of quaternary ammonium salt so as to apply it as a sorbent for petroleum-derived fuels. Bentonite clay was organophilizated by the intercalation of quaternary ammonium salts such as cetyl-pyridinium chloride and benzalkonium chloride. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, N2 physisorption and infrared spectroscopy techniques. The clay similarity with petroleum-derived fuels, gasoline and diesel oil were defined by sorption and swelling tests. The increase in basal spacing and the appearance of absorption bands related to the CH2 and CH3 groups confirm the efficiency of Brazilian organoclays. Removal percentages between 50 and 60 for benzene, toluene and xylene indicate the potential of organoclay in the remediation of areas contaminated by petroleum-derived fuels.

A obtenção da coluna total de ozônio a partir de detectores de radiação ultravioleta (UV) como Radiômetros e Espectroradiômetros é de grande importância, visto que os medidores de ozônio como o Espectrofotômetro Brewer são muito caros e, portanto, de difícil obtenção. Este trabalho tem como objetivo encontrar modelos matemáticos que relacionem a razão entre as radiações UVB/UVA do Espectroradiômetro MS 701, dos Radiômetros UV-B MS 212 W e UV-A MS 212 A e as medidas de ozônio efetivo obtidas a partir do Espectrofotômetro Brewer MKIII #167, instalados no Observatório Espacial do Sul, no Sul do Brasil. Os períodos selecionados para análise foram o ano de 2003 para o Espectroradiômetro e o de 2005 para os Radiômetros, onde foram utilizados apenas dias sem interferências de nuvens. Os modelos matemáticos encontrados foram funções exponenciais com coeficiente de correlação R = 0,85 para a relação com o Espectroradiômetro e de R = 0,99 para a relação com os Radiômetros. Os dados de ozônio efetivo obtidos a partir dos detectores UV foram ajustados aos seus respectivos modelos e comparados com a coluna total de ozônio fornecida pelo Espectrofotômetro Brewer e pelo TOMS. A diferença média entre os valores obtidos da coluna total de ozônio do Espectroradiômetro e o Brewer foi de 0,7% e com o TOMS foi de 3,1% enquanto a comparação para a coluna total de ozônio fornecida pelos Radiômetros com o Brewer apresentou diferença média de 2% e com o TOMS de 4,3%. Estes resultados comprovam a eficiência do método utilizado e uma boa aproximação das funções encontradas.

The total ozone has been obtained through ultraviolet (UV) radiation detectors as Radiometers and Spectroradiometers. It was used as an alternative method for stations which do not have expensive equipments to measure ozone such as Brewer Spectrophotometers. The aim of this work is to find mathematical models using the relation between UVB/UVA radiation ratios measured by Spectroradiometer MS 701 and Radiometers UV-B MS 212 W and UV-A MS 212 A and effective ozone measured by Brewer Spectrophotometer MKIII #167. The equipments are installed at the Southern Space Observatory, at southern Brazil. The periods selected for this analysis were the year of 2003 for Spectroradiometer and of 2005 for Radiometers, where only clean sky days were used. The mathematical models that we have derived were exponential functions with correlation coefficient of the order of 0.85 for the relation with Spectroradiometer and of order of 0.99 for the relation with Radiometers. The effective ozone data obtained by Spectroradiometer and Radiometers were fitted with these models and compared with the Brewer and TOMS total ozone. The average difference between the Spectroradiometer model results and Brewer total ozone was 0.7% and between the Spectroradiometer model and TOMS ozone data was 3.1%, while the comparison between the average difference of Radiometers' model and Brewer ozone data was 2% and between Radiometers' model and TOMS was 4.3%. It verifies the efficiency of the method used and the good approximation of the models.