In this work, we studied the formation of hierarchical porous cartridges by means of bacterial cellulose impregnation with the zeolites A and X. Cellulose was successfully produced by Komagataeibacter genus and the zeolites were obtained by hydrothermal route. The composites were formed using both oxidized and non-oxidized cellulose. Different characterization techniques were used to analyze the resulting materials like powder X-ray diffraction, spectroscopic techniques (infrared vibrational spectroscopy and nuclear magnetic resonance), electron microscopy, thermal analyses, as well as ionic exchange experiments. The results show that the composites present layers with large voids among them, formed by cellulose nanofibrils tangling the particles in the oxidized samples, and shiftings in the bands referent to the carboxilyc groups and hydrogen bondings. The oxidation step for the cellulose seems to be important for the hierarchization and a positive effect on the cartridges is found for Ca2+ ionic exchange tests. Thus, these components can be successfully mixed to form cartridges with potential use at gas and liquid adsorption technologies.

Neste estudo, fibras de coco verde foram incorporadas em uma matriz composta de glúten de milho (GM) e poli(hidroxibutirato-co-valerato) (PHBV). As composições foram processadas por extrusão, onde o teor máximo de glúten adicionado à matriz para obter misturas com viscosidade suficientemente baixa para o processamento foi de 50% (em peso) em relação ao teor de PHBV. O teor de fibras nos compósitos variou de 5 a 20% por peso em relação ao peso total dos polímeros. Os plastificantes usados foram acetil tributil citrato (ATBC) e glicerol. Os materiais extrudados foram moldados por compressão a quente para obtenção de corpos de prova para a caracterização das propriedades de absorção de água, solubilidade em água, resistência mecânica, além de propriedades termo-dinâmico-mecânicas (DMTA) e morfológicas. Foi observado que as matrizes apresentaram duas transições vítreas (Tg's) uma para cada componente, indicando que as mesmas são compostas de duas fases (GM) e PHBV. A adição do PHBV ao glúten favoreceu ao aumento da rigidez e houve diminuições significativas na absorção de água e na solubilidade em água, enquanto a presença das fibras provocou, em algumas composições, um aumento no módulo de elasticidade e na resistência à tração.

Green coconut fibers were added as reinforcement in polymer matrices comprised of corn gluten meal (GM) and PHBV. The composites were processed by extrusion. The maximum gluten content added in the matrix to obtain mixtures with low enough viscosity for the extrusion process was 50% (by weight) in relation to PHBV content. The content of fibers used in the composites varied from 5% to 20% (by weight) of the total polymers weight (GM and PHBV). Glycerol and acetyl tributyl citrate (ATBC) were used as plasticizers. The matrices and composites obtained were molded by heat compression and further characterized. Water absorption at equilibrium and water solubility decreased as the PHBV content increased. The Young's modulus and ultimate tensile strength increased with fiber content in the matrix for some compositions. GM/PHBV matrices exhibited two distinct glass transitions, one for each component, indicating a two-phase system. DMTA results and the morphology of the composites analyzed under the scanning electron suggested that the reinforcing effect of the green coconut fibers in GM/PHBV matrices was not homogeneous.

Os fatores antrópicos e naturais que determinam a qualidade das águas superficiais na Bacia do Baixo Acaraú foram identificados pelo emprego da técnica de Análise Fatorial/Análise da Componente Principal (AF/ACP). Foram realizadas quatro campanhas no período de fev./2003 a mar./2004, em sete pontos de amostragem localizados ao longo do Rio Acaraú. Foram analisados 25 parâmetros físico-químicos e bacteriológicos. Pelo emprego da AF/ACP, identificou-se que o modelo de melhor ajuste para expressar a qualidade das águas na Bacia do Baixo Acaraú foi aquele composto por quatro fatores, explicando 82,1% da variância total. O primeiro fator representa a componente de sólidos em suspensão, expressando o processo de erosão e escoamento superficial. O segundo fator é definido por uma componente de nutrientes associados aos esgotos sanitários, às áreas agrícolas e a outras fontes de poluição difusa; o terceiro fator é indicativo da ação antrópica (componente orgânica), enquanto o quarto representa os sais solúveis que expressam o processo natural do intemperismo das rochas. Outro ponto observado é que a análise fatorial não resultou em grande redução no número de variáveis, uma vez que o melhor ajuste do modelo ocorreu com a inclusão de 18 das 25 variáveis analisadas.

Multivariate statistical technique, factor analysis/principal component analysis (FA/PCA), was applied to identify the human activity effects and natural processes on surface water quality in Low Acaraú basin, Ceará, Brazil. Water samples were collected in four different campaigns from Feb/2003 to Mar/2004, at seven sampling stations sited in low Acaraú watershed. Twenty-five physical, chemical and bacteriological parameters were examined in this study. The FA/PCA allowed the identification of the total variance. The best model was adjusted with four components, explaining 82.1% of the data variance. The first factor was mainly associated with suspended solids defining the erosion process and runoff; that is, a suspended solids component. The second factor was mainly associated with sewage, agricultural runoff and others non-pontual pollution; the third one was defined as an organic component and represents the anthropogenic activites; while the fourth was mainly correlated with soluble salt, expressing the weathering and leaching. Besides, the factorial analysis did not result in data reduction, since 18 of the 25 parameters have been kept to explain 82% of the data variance.

Green coconut shells were treated with acid, base and hydrogen peroxide solutions for 3, 6, 12 and 24 h for removing toxic metals from synthetic wastewater. The removal of ions by the adsorbent treated with 0.1 mol L-1 NaOH/ 3h was 99.5% for Pb2+ and 97.9% for Cu2+. The removal of Cd2+, Ni2+, Zn2+, using adsorbent treated with 1.0 mol L-1 NaOH/3 h, was 98.5, 90.3 and 95.4%, respectively. Particle size, adsorbent concentration and adsorption kinetics were also studied. An adsorbent size of 60-99 mesh and a concentration of 30-40 g/L for 5 min exposure were satisfactory for maximum uptake of Pb2+, Ni2+, Cd2+, Zn2+ and Cu2+ and can be considered as promising parameters for treatment the aqueous effluents contaminated with toxic metals.