Abstract TiO2 immobilized in Sepiolite (TiO2/Sep) was successfully prepared by the sol-gel technique, with titanium isopropoxide as the precursor for the formation of TiO2 in the anatase phase calcined at 400 °C. The prepared samples were characterized by X-ray diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy coupled to energy dispersive spectroscopy, and thermogravimetric analysis. The results showed that TiO2/Sep structure was identified in all characterizations, showing the specific peaks, bands, mass loss, and morphology after the impregnation process. Photocatalytic experiments were performed under UV irradiation with various photocatalyst concentrations and pH effects in the reaction. The prepared samples presented 72% photocatalytic efficiency for eosin (EA) dye discoloration after 150 min under UV light. This efficiency was attributed to the radicals generated from the TiO2 and the high specific surface area, showing that TiO2/Sep is promising candidate in the degradation of organic pollutants.

ABSTRACT Miniaturization has been a trend in the instrumentation of chemical analyzes. The interest in miniaturization stems from the perceived benefits of faster, easier, less expensive and less wasteful analyzes than the tradition analyses. Thus, this work proposes a miniaturization of photocatalytic tests using a microplate reader for the analysis of several results, using only microliters of solution. The present work investigates the heterogeneous photocatalysis of the eosin yellow, acid yellow 73 and basic yellow 2 dyes, in the presence of zinc oxide (ZnO) and titanium dioxide (TiO2) catalysts, under irradiation in the visible light and ultraviolet light. Dye degradation was evaluated using a microplate reader (Elisa Polaris®), a photometric device that performs colorimetric readings in the 0-3 absorbance (ABS) range at wavelengths of 405, 450, 492 and 630 nm. The kinetic study was performed using the Langmuir-Hinshelwood law. It was verified that the degradation rates were higher than 90% over a period of 120 minutes for all the studied systems, especially the system composed of acid yellow dye 73 and the ZnO catalyst, which reached a degradation of 96.23% in 120 minutes.

RESUMO A carnaúba (Copernicia prunifera) é uma espécie vegetal comum no Nordeste do Brasil e possui grande importância comercial no que se refere a exploração/exportação da cera extraída de suas folhas. Assim, visando o pleno aproveitamento dos resíduos gerados na cadeia produtiva da carnaúba, neste trabalho é apresentada a caracterização da palha e do talo “in natura”, bem como pós densificação (produção de briquetes), com o objetivo de investigar a possível aplicação como biocombustíveis. A metodologia experimental envolveu a determinação dos teores de umidade, cinzas, voláteis, carbono fixo, poder calorífico superior, ensaios de resistência ao impacto, compressão diametral e termogravimetria. A análise elementar (CHNS/O) também foi realizada. Com relação ao teor de voláteis os valores obtidos foram 70,89% e 81,12% para a palha e o talo in natura e 70,02% e 80,41%, para os briquetes de palha e talo. Para carbono fixo obteve-se 19,98% e 16,08 % para a palha e o talo in natura e 20,9% e 16,8%, para os briquetes de palha e talo, respectivamente. Quanto ao conteúdo energético, a palha in natura obteve poder calorífico superior da ordem de 17,51 MJ/kg e o talo in natura 17,29 MJ/kg. No que se refere a densidade energética, a produção dos briquetes proporcional aumentos da ordem de 328,9% (2,98 para 12,78 kJ/cm3) para a palha e de 292% (2,89 para 11,33 kJ/cm3) para o talo. Quanto ao ensaio de resistência mecânica, o briquete de palha apresentou uma resistência de 0,1 MPa e o briquete de talo de 0,3 MPa. Diante do exposto, pode-se inferir que a palha e o talo de carnaúba possuem potencial para utilização como biocombustíveis.

ABSTRACT The carnauba (Copernicia prunifera) is a common plant species in Northeast Brazil and has a great commercial importance due to exploration/exportation of the wax extracted from its leaves. Therefore, aiming the use of the residues derived from carnauba's production chain, this work shows the characterization of the stalk and straw "in natura", and after densification (briquettes production), with the aim to investigate the possible application as biofuels. The analyses involved the determination of moisture, ash, volatile matter, fixed carbon, gross calorific value, impact resistance, diametrical compression, and thermogravimetry. Elemental analysis (CHNS/O) was also performed. In relation to the volatile matter the carnauba's straw and stalk "in natura" obtained 70.89% and 81.12% while carnauba briquettes of straw and stalk showed 70.02% and 80.41%, respectively. For the fixed carbon - a calculated value - the results were 19.98% for the straw and 16.08% for the stalk. After briquettes production were obtained 20.9% and 16.8% for the straw and the stalk, respectively. In relation to the gross calorific value, the carnauba's straw and stalk "in natura" obtained 17.51 MJ/kg and 17.29 MJ/kg. For the energetic density, briquettes' production provided an increase of 328.9% (2.98 to 12.78 kJ/cm3) for the straw and 292% (2.89 to 11.33 kJ/cm3) for the stalk. The mechanical resistance test for the carnauba's straw briquette showed 0.1 MPa and the carnauba's stalk briquette showed 0.3 MPa. According to the results, it can be inferred that the carnauba's straw and stalk have the potential for use as biofuels.

RESUMO Objetivou-se quantificar o conteúdo de nutrientes nos componentes da biomassa da parte aérea das espécies de maior valor de importância em duas áreas de Caatinga e avaliar a eficiência dessas plantas no uso desses nutrientes. A pesquisa foi realizada na fazenda Itapemirim, no município de Floresta - PE, onde foram estudadas duas áreas de vegetação de Caatinga em fases distintas de sucessão ecológica, apresentando características distintas, uma em estágio de regeneração e outra preservada. Na amostragem foi realizado um inventário inicial se lançando 40 parcelas de 400 m2 em cada área, tendo como nível de inclusão CAP ≥ 6,0 cm. Para análise da biomassa foram utilizadas as cinco espécies de maior valor de importância de cada área, a escolha dos indivíduos foi de forma aleatória e cada planta escolhida teve medida sua circunferência a altura do peito e na base. No processo de pesagem e amostragem dos componentes da parte aérea, as árvores escolhidas foram derrubadas e em seguida foram pesados todos seus componentes e retirada uma amostra para realização das análises químicas. Nesse estudo observou-se que o levantamento inicial nas duas áreas a Poincianella bracteosa foi a espécies que apresentou maior conteúdo de nutrientes na biomassa total acima do solo em ambas as áreas, e o componente galho foi o de maior contribuição no conteúdo de nutrientes na biomassa total, sendo N o nutriente mais acumulado no componente folha, e o Ca nos componentes lenhosos em ambas as áreas, já os nutrientes que apresentaram a maior eficiência de utilização nutricional nas espécies estudadas em ambas as áreas, foram o S e o P.

ABSTRACT It was aimed to know the content of mineral nutrients in the components of the biomass of the aerial part of the species of the biggest value of importance in two areas of Caatinga and to evaluate the efficiency of these plants in the use of these nutrients. The research was carried through Itapemirim farm in Floresta, Pernambuco state, where two areas of vegetation of Caatinga inside the farm were studied, presenting distinct characteristics, one in period of training of regeneration, and the other one was preserved. In the sampling, an initial inventory was made launching 40 parcels of 400m2 in each area, having as level of inclusion CBH ≥ 6.0 cm. For the analysis of biomass, it was used the five species of the biggest value of importance of each area, the choice of the individuals was at random and each chosen plant had measured its circumference the height of the chest and in the base. In the process of weighing and sampling the components of the aerial part, the chosen trees had been knocked down and after that, their components were all weighed and a sample was removed for the chemical analyses. In this study, it was observed that the initial survey in the two areas, bracteosa Poincianella was the species that presented greater content of nutrients in the total biomass above the ground in both the areas. The component twig was of bigger contribution in the content of nutrients in the total biomass, being N the accumulated nutrient more in the component leaf, and in timber components in both the areas, once the nutrients that presented the greatest efficiency for their use in the plants studied in both the areas, were S and P.

The present study aimed to investigate the degradation of poly(ethylene oxide) (PEO) in the presence of cationic dye crystal violet irradiated under visible light. The preparation of the samples was done in the form of films obtained by casting. Degradation tests were carried out by 120 hours at room temperature. The degradation kinetics of the dye and polymer were accompanied by UV-Vis spectrophotometry and viscosimetry technique. The UV-Vis Spectra showed 81.2% degradation of the dye. In addition, it was observed a broadening of the absorption band of the polymer and the reduction of its viscosity, which features degradation. In this way, it is possible to affirm that the crystal violet dye, at the studied concentration, contributed to the degradation process of PEO.

RESUMO: A longevidade das hastes florais é um dos principais aspectos observados na produção de flores para corte, constituindo-se um pré-requisito para a qualidade do produto e sucesso da comercialização. Nesse sentido, objetivou-se avaliar a conservação de inflorescências de helicônias com ou sem renovação da água de manutenção, previamente adubadas com doses crescentes de nitrogênio e potássio. Foram utilizadas inflorescências de helicônias da espécie Heliconia psittacorum x H. spathocircinata cv. Golden Torch cultivadas a céu aberto no Setor de Floricultura da UFPI, Bom Jesus (PI), sob doses crescentes de adubação com N e K. O delineamento foi em blocos casualizados em esquema fatorial 4 x 4 x 2, correspondendo a: i) doses de N (0, 120, 180 e 240 g de N cova1); ii) doses de K (0, 120, 180 e 240 g de K2O cova-1); e iii) renovação da água de manutenção (sem e com renovação) com três repetições e três hastes cada uma. Fora realizado a avaliação de absorção de água pelas hastes florais, perda de massa fresca das hastes florais, massa seca das hastes florais e longevidade pós-colheita. A dose de 180 g cova-1 tanto de N quanto K proporcionou a maior longevidade das hastes florais com manutenção da qualidade. A absorção de água pelas hastes florais e sua massa seca após a colheita foram influenciadas pela adubação prévia de N e K. A renovação da água de manutenção também influenciou positivamente na longevidade das hastes florais, sendo um manejo indicado para manter a qualidade pós-colheita.

ABSTRACT: The post-harvest of floral stems is one of the main features observed in the production of flowers for cutting, becoming a prerequisite for product quality and successful marketing. In this sense, the objective was to evaluate the conservation of heliconias inflorescences with or without renewal of the water maintenance, previously fertilized with increasing doses of nitrogen and potassium. Inflorescences of Heliconia psittacorum x H. spathocircinata cultivar Golden Torch were used and grown in open conditions in the Floriculture area at UFPI, city of Bom Jesus, Piauí State under increasing doses of fertilization with N and K. The stems were harvested in the morning, standardized and placed in containers with 500 mL of water. The design was a randomized block in factorial 4 x 4 x 2, corresponding to: i) N doses (0, 120, 180, and 240 g N hole-1), ii) K doses (0, 120, 180, and 240 g K2O hole-1), and iii) renewing the water maintenance in vase (with and without renewal) with three replicates of three stems each. Some evaluations were observed during the Study, such as: the water uptake by the flower stems; loss of fresh weight of the flower stems, dry weight of the flower stems and post-harvest longevity. The dose of 180 g hole-1 both as N and K provided the longevity of the flower stems with quality maintenance. The absorption of water by the flower stems and its dry mass after harvesting are influenced by previous fertilizer N and K. The renewal of the water maintenance also positively influence the longevity of flower stems and its a management indicated to maintain quality post-harvest.

Diante dos altos custos de produção e da necessidade de conservação dos recursos ambientais, vem-se buscando alternativas agroecológicas, priorizando a qualidade do produto e reduzindo o nível de contaminações dos agroecossistemas. Assim, realizou-se um trabalho com o objetivo de avaliar o efeito de biofertilizantes líquidos, adubação com 50 e 100% da recomendação de adubação nitrogenada e potássica em cobertura (NK), na ausência e presença de calagem, aplicado no solo sobre o estado nutricional e clorofila foliar do maracujazeiro-amarelo em Bom Jesus, PI. Adotou-se o delineamento em blocos casualizados com tratamentos distribuídos em esquema fatorial 2 x 3 x 2, correspondentes à calagem, biofertilizantes (sem bio, biofertilizantes simples e enriquecido) e adubação mineral com quatro repetições. Os teores dos macronutrientes foliares de plantas de maracujazeiro-amarelo são influenciados pelos tipos de biofertilizantes, calagem e adubação mineral. A dose 100% de NK é mais eficiente no teor de N, K, Ca e Mg na massa seca foliar do maracujazeiro-amarelo.

Due to the high production costs and the preservation necessity of environmental resources, ecological alternatives have been seeking for, emphasizing product quality, mitigating the level of contaminations of the agroecossystems. So, we carried out a study aiming to evaluate the effect of liquid biofertilizers, fertilization with 50 and 100% of the recommendation of nitrogen and potassium fertilization on coverage (NK), in the absence and presence of liming, applied to the soil on the nutritional status and leaf chlorophyll in the yellow passion fruit Bom Jesus, PI. We adopted the randomized block design with treatments arranged in a factorial 2 x 2 x 3, corresponding to liming, biofertilizers (without biofertilizer, simple biofertilizer and biofertilizer enriched) and mineral fertilizer with four replications. The contents of macronutrients in leaves of yellow passion fruit plants are influenced by the types of biofertilizers, liming and mineral fertilization. Dose 100% of NK is efficient in the accumulation of N, K, Ca e Mg in the leaf drought weitght of the yellow passion fruit.

O objetivo deste trabalho foi avaliar o potencial de plantas de cobertura semeadas em diferentes sistemas de cultivo quanto à produção de fitomassa e acúmulo de nutrientes, no cerrado piauiense. O experimento foi instalado no ano agrícola 2010/2011, na Serra do Quilombo, município de Bom Jesus (Piauí). O arranjo utilizado foi em parcelas subdivididas, com os seguintes sistemas de manejo do solo: preparo convencional e plantio direto avaliados nas parcelas e, nas subparcelas, os sistemas de produção: S1 - Soja no verão em monocultura; S2 - Soja no verão e Penissetum glaucum na safrinha; S3 - P. glaucum pré-soja de verão e sobressemeadura de Urochloa ruziziensis na soja no estádio R5.5; S4 - Soja de verão e sobressemeadura de P. glaucum na soja no estádio R5.5; S5 - Milho verão + U. ruziziensis simultâneo. Utilizou-se o delineamento em blocos casualizados, com quatro repetições. Os sistemas com a sobressemeadura do P. glaucum e do U. ruziziensis na soja e o consórcio de milho + U. ruziziensis destacaram-se na produção de fitomassa seca, cobertura do solo e acúmulo de nutrientes durante a entressafra no cerrado piauiense. Os nutrientes com maior taxa de acúmulo pelas plantas de cobertura foram o nitrogênio e o potássio.

The objective of this work was to evaluate the biomass production and nutrient accumulation in potential cover crops sown in different cropping systems in the Brazilian Cerrado of Piauí State. The experiment was conducted in the crop season 2010/2011 in the Serra do Quilombo, county of Bom Jesus, Piauí, Brazil. This study was arranged in split plot scheme, with soil management systems (conventional tillage and no-tillage) evaluated in plots and crop systems in subplots: S1- Soybean monoculture in the crop-season; S2 - Soybean in crop-season and Pennisetum glaucum for off-season; S3 - P. glaucum before soybean crop-season and Urochloa ruziziensis oversown on soybean in the phenological stage R5.5; S4 - Soybean crop-season and P. glaucum oversown on soybean in R5.5; S5 - Maize + U. ruziziensis simultaneously in crop-season. The experimental design was in randomized blocks, with four replications. The crop systems with oversown of P. glaucum and U. ruziziensis on soybean and the consortium maize + U. ruziziensis improved the biomass production, soil coverage and nutrient accumulation during the off-season in the Cerrado from Piauí State, Brazil. The nutrients with greater accumulation rate by cover crops were nitrogen and potassium.