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The organic xerogel (OX) was synthesized through sol-gel polymerization of formaldehyde and resorcinol in inverse emulsion using Na2CO3 as a catalyst. Meanwhile, OX containing sepiolite (OX-Sep) and vermiculite (OX-Ver) were prepared similarly to OX but adding clays during synthesis. All materials were mesoporous and presented spherical morphology, and the surface of these materials exhibited an acidic character because the concentration of acidic sites was higher than those of basic sites. Cd(II) adsorption from aqueous solutions onto OX, OX-Sep, and OX-Ver was examined, and the OX-Sep showed the highest adsorption capacity towards Cd(II) of 189.7 mg/g, being 1.5, 2, and 36 times higher than that of OX-Ver, OX, and Sep. The OX-Sep capacity for adsorbing Cd(II) was significantly lessened by decreasing the pH from 7 to 4 and raising the ionic strength from 0.01 N to 0.1 N. This trend was ascribed to electrostatic attraction between the Cd+2 in water and the negatively charged surface of OX-Sep. Besides, desorption studies at pH 4 showed that the average desorption percentage of Cd(II) adsorbed on OX-Sep was 80%. The characterization results and the effect of the operating conditions on the adsorption capacity proved that electrostatic attraction and cation exchange play a crucial role in the adsorption mechanism.

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Background: Pesticides are applied for pest control during the production of cereal grains used in beer production. Given the risks for consumers, it is important to analyze the pesticide residues. Objective: Quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methods are very effective, and improvement in the cleanup step is an important approach. Methods: Primary secondary amine (PSA) and magnesium silicate were evaluated for dispersive-solid-phase extraction (d-SPE) cleanup step in extracts provided by the QuEChERS method in combination with GC-tandem MS for the determination of acetamiprid, terburfos, alachlor, ametryn, atrazine, azoxystrobin, carbofuran, carbosulfan, cypermethrin, deltamethrin, difenoconazole, esfenvalerate, flutriafol, thiamethoxam, and parathion-methyl in lager beer. Results: The amount of 50 mg of magnesium silicate was suitable for cleaning up beer extract as an alternative d-SPE material to PSA. The method was validated using beer fortified with pesticides at three concentration levels (0.002, 0.01, and 0.1 µg/mL). Average recoveries ranged from 70 to 123%, with RSDs between 0.3 and 10.5 %. Matrix effects were observed by comparing the slope of matrix-matched standard calibration with that of solvent. The method provided good linearity at the concentration levels of 0.001-2.5 µg/mL. Detection limits ranged from 0.0001 to 0.0007 µg/mL and quantification limits ranged from 0.001 to 0.006 µg/mL. The method was applied to nine beer brands. Conclusions: Results showed that magnesium silicate is an efficient alternative cleanup material to reduce analysis costs while maintaining the method reliability and accuracy. Highlights: Magnesium silicate was effective as adsorbent for d-SPE step in the analysis of pesticides in beer.

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OBJECTIVE: To remove dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) adsorbed on alumina, silica and sepiolite through biodesulfurization (BDS) using Rhodococcus Rhodochrous spp., that selectively reduce sulfur molecules without generating of gaseous pollutants. RESULTS: The adsorption of DBT and 4,6-DMDBT was affected by the properties of the supports, including particle size and the presence of surface acidic groups. The highest adsorption of both sulfur-containing organic molecules used particle sizes of 0.43-0.063 mm. The highest percentage removal was with sepiolite (80 % for DBT and 56 % for 4,6-DMDBT) and silica (71 % for DBT and 37 % for 4,6-DMDBT). This is attributed to the close interaction between these supports and the bacteria. CONCLUSIONS: Biodesulfurization is effective for removing the sulfur-containing organic molecules adsorbed on inorganic materials and avoids the generation of gaseous pollutants.

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Clay mineral facial masks are used to treat some dermatological diseases, just for cleansing or reduce the amount of oil secreted by sebaceous glands. There are several types of clays, which vary in mineralogical and chemical composition, color and origin. However, the literature lacks studies involving clay facial masks, in particular regarding their influence on skin´s biomechanical properties. Thus, this work aimed to characterize colored clays and evaluate its influence on skin frmness and elasticity by a short-term clinical study. Different clays (named in this study magnesium aluminum silicate - MAS, white, pink and green) were chemically characterized, and facial mask formulations were prepared. The short-term clinical study was performed through the application of formulations on the skin. The skin frmness and elasticity were assessed before treatment and after mask removal. The statistical analysis showed no signifcant influence of time or formulations in those parameters, although volunteers reported the sensation of mechanical tension after the removal of the clay facial masks. Thus, the composition of the different clays did not affect the skin viscoelasticity behavior in the short-term clinical study, and a long-term use of this type of formulation must be indicated to observe all the expected benefts.(AU)

Máscaras faciais argilosas são utilizadas para tratar algumas doenças dermatológicas, apenas para a limpeza ou reduzir a quantidade de óleo secretado pelas glândulas sebáceas. Existem vários tipos de argilas, que variam em composição mineral, química, cor e origem. No entanto, a literatura carece de estudos envolvendo máscaras faciais argilosas, em particular em relação a sua influência nas propriedades biomecânicas da pele. Assim, este trabalho teve como objetivo caracterizar argilas coloridas e avaliar sua influência sobre a frmeza e elasticidade da pele por meio de um estudo clínico de curto prazo. Diferentes argilas (chamadas neste estudo de silicato de alumínio e magnésio - MAS, branca, rosa e verde) foram caracterizadas quimicamente, e formulações de máscaras faciais foram preparadas. O estudo clínico de curto prazo foi realizado por meio da aplicação das formulações na pele. A frmeza e elasticidade da pele foram avaliadas antes do tratamento e após a remoção da máscara. A análise estatística mostrou nenhuma influência signifcativa do tempo ou das formulações nesses parâmetros, embora os voluntários tenham reportado sensação de tensão mecânica, após a remoção das máscaras faciais argilosas. Assim, a composição das diferentes argilas não afetou o comportamento visco-elástico da pele no estudo clínico de curto prazo, e uma utilização de longa duração poderia ser indicada com a fnalidade de se observar todos os benefícios esperados.(AU)

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The present study aims to evaluate the operating costs of biodiesel production using palm oil in a pilot-scale plant with a capacity of 20,000 L/day (850 L/batch). The production plant uses crude palm oil as a feedstock, and methanol in a molar ratio of 1:10. The process incorporated acid esterification, basic transesterification, and dry washing with absorbent powder. Production costs considered in the analysis were feedstock, supplies, labor, electricity, quality and maintenance; amounting to $3.75/gal ($0.99/L) for 2013. Feedstocks required for biodiesel production were among the highest costs, namely 72.6% of total production cost. Process efficiency to convert fatty acids to biodiesel was over 99% and generated a profit of $1.08/gal (i.e., >22% of the total income). According to sensitivity analyses, it is more economically viable for biodiesel production processes to use crude palm oil as a feedstock and take advantage of the byproducts such as glycerine and fertilizers.

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Sepiolite clay mineral was used as a support for the immobilisation of the peroxidase enzyme from ingá-cipó (Inga edulis Mart.) and was used with graphite powder, multi-walled carbon nanotubes (CNTs), mineral oil, and nafion 0.5% (v/v) in the development of a new biosensor for the determination of the antioxidant tert-butylhydroquinone (TBHQ) by square-wave voltammetry (SWV). For the optimisation and application of the biosensor, several parameters were investigated to determine the optimum experimental conditions using SWV. The best performance was obtained using a 0.1 mol L(-1) phosphate buffer solution (pH 7.0), 4.0 × 10(-4) mol L(-1) hydrogen peroxide, a frequency of 50 Hz, a pulse amplitude of 60 mV, and a scan increment of 6 mV. The biosensor showed good repeatability and reproducibility and remained stable for a period of 20 weeks. The analytical curve revealed a linear response range of 1.65 to 9.82 mg L(-1) (r = 0.994) with detection and quantification limits of 0.41 and 1.25 mg L(-1). A recovery study of TBHQ in salad dressing samples yielded values from 99.6-104.8%. The proposed biosensor was successfully used for the determination of TBHQ in commercial salad dressing samples, giving a relative error of 5.4% in relation to the comparative method (chromatographic).

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A method was developed using matrix solid-phase dispersion, together with liquid chromatography with ultraviolet diode array detector for determination of carbofuran, difenoconazole, ß-cyfluthrin, spirodiclofen and thiophanate-methyl in stem of coconut palm. The best results were obtained using 2.0 g of stem, 1.6 g of Florisil as sorbent and cyclohexane:acetone mixture (4:1). The method was validated using stem samples spiked with pesticides at four concentration levels (0.05-2.0 µg/g). Average recoveries ranged from 70 % to 114.3 %, with relative standard deviations between 1.2 % and 19.2 %. Detection and quantification limits were in the ranges 0.02-0.03 and 0.05-0.1 µg/g, respectively.

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In this work, chrysotile was used as support to grow carbon nanotubes and nanofibers to produce fibrous amphiphilic magnetic nanostructured composites. Iron impregnated on the chrysotile surface at 1, 5 and 15 wt% was used as catalyst to grow carbon nanostructures by CVD (chemical vapor deposition) with ethanol at 800°C. Raman, TG/DTA, Mössbauer, XRD, BET, SEM, TEM, elemental analyses and contact angle measurements suggested the formation of a complex amphiphilic material containing up to 21% of nanostructured hydrophobic carbon supported on hydrophilic Mg silicate fibers with magnetic Fe cores protected by carbon coating. Adsorption tests for the hormone ethynilestradiol (EE), a hazardous water contaminant, showed remarkable adsorption capacities even compared to high surface area activated carbon and multiwall carbon nanotubes. These results are discussed in terms of the hydrophobic surface of the carbon nanotubes and nanofibers completely exposed and accessible for the adsorption of the EE molecules combined with the hydrophilic Mg silicate surface which allows good dispersion in water. The composites are magnetic and after adsorption the dispersed particles can be removed by a simple magnetic process. Moreover, the fibrous composites can be conformed as threads, screens and pellets to produce different filtering media.

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O calcário é o corretivo da acidez mais utilizado nos solos agrícolas brasileiros, porém benefícios importantes podem ser obtidos com o uso de silicatos de cálcio e magnésio. Objetivou-se comparar o efeito neutralizante da acidez do solo por meio de calagem e silicatagem, com incubação dos corretivos em condições de solo com diferentes umidades. O experimento foi conduzido no Laboratório de Análise Química de Solos, na Universidade do Oeste Paulista-UNOESTE, utilizando solo coletado na camada de 0 a 20 cm de um Argissolo Vermelho-Amarelado distrófico. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 2x2x5, sendo dois corretivos (calcário dolomítico e silicato de Ca e Mg), duas umidades do solo (80 e 20% da umidade de saturação) e cinco épocas de avaliação (60, 90, 120, 150 e 180 dias após incubação) dos atributos químicos do solo. Os resultados foram comparados por meio de análise de variância e as variáveis umidades do solo e corretivos foram submetidas ao teste de Tukey (p<0,05). Já o efeito da época de amostragem foi analisado por meio de análise de regressão. O silicato apresenta maior capacidade neutralizante da acidez do solo que o calcário, e com isso sua dosagem deve ser mais bem estudada, pois a utilização do cálculo para determinar a necessidade de calagem pode superestimar a necessidade de silicatagem. A reatividade do calcário no solo não é influenciada quando o solo está com umidade entre 20 e 80% da umidade de saturação, diferentemente do silicato, que tem a sua reatividade potencializada na condição de maior umidade do solo. A ação corretiva da acidez do solo por ambos os corretivos permanece crescente até 180 dias da incubação, porém, resultados satisfatórios já são obtidos com 60 dias de incubação do solo.

The lime is the acidity corrective more used in brazilian agricultural soils, but important benefits can be obtained from calcium and magnesium silicates. The aim of this study was to compare the effect of neutralizing soil acidity by application of lime and silicate, with incubation of the correctives in soil conditions more or less moisture. The experiment was conducted in the Soil Chemical Analysis Laboratory at the UNOESTE, using soil collected in the layer 0-20 cm of a Sandy Loam Argisol. The experiment was carried out in a completely randomized in a 2x2x5 factorial scheme, with two correctives (lime and silicate of Ca and Mg), two soil moistures (80 and 20% moisture soil saturation) and five times (60, 90, 120, 150 and 180 days after incubation) of soil chemical properties. It was submitted to variance analysis and the effects of soil moisture and correctives were evaluated by Tukey test (p<0,05) and the incubations time were evaluated by regression analysis. The silicate has a higher neutralizing capacity of soil acidity than lime, and thus its dosage should be further investigated, because the use of the calculation to determine the lime requirement can overestimate the need for silicate applied. The lime reactivity in the soil is not influenced with soil moisture between 20 and 80% moisture saturation, unlike silicate, which has its soil reactivity enhanced in the condition of higher moisture. The soil corrective action acidity by both corrective remains increasing up to 180 days of incubation, however, satisfactory results are already obtained with 60 days of soil incubation.

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O calcário é o corretivo da acidez mais utilizado nos solos agrícolas brasileiros, porém benefícios importantes podem ser obtidos com o uso de silicatos de cálcio e magnésio. Objetivou-se comparar o efeito neutralizante da acidez do solo por meio de calagem e silicatagem, com incubação dos corretivos em condições de solo com diferentes umidades. O experimento foi conduzido no Laboratório de Análise Química de Solos, na Universidade do Oeste Paulista-UNOESTE, utilizando solo coletado na camada de 0 a 20 cm de um Argissolo Vermelho-Amarelado distrófico. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 2x2x5, sendo dois corretivos (calcário dolomítico e silicato de Ca e Mg), duas umidades do solo (80 e 20% da umidade de saturação) e cinco épocas de avaliação (60, 90, 120, 150 e 180 dias após incubação) dos atributos químicos do solo. Os resultados foram comparados por meio de análise de variância e as variáveis umidades do solo e corretivos foram submetidas ao teste de Tukey (p<0,05). Já o efeito da época de amostragem foi analisado por meio de análise de regressão. O silicato apresenta maior capacidade neutralizante da acidez do solo que o calcário, e com isso sua dosagem deve ser mais bem estudada, pois a utilização do cálculo para determinar a necessidade de calagem pode superestimar a necessidade de silicatagem. A reatividade do calcário no solo não é influenciada quando o solo está com umidade entre 20 e 80% da umidade de saturação, diferentemente do silicato, que tem a sua reatividade potencializada na condição de maior umidade do solo. A ação corretiva da acidez do solo por ambos os corretivos permanece crescente até 180 dias da incubação, porém, resultados satisfatórios já são obtidos com 60 dias de incubação do solo.(AU)

The lime is the acidity corrective more used in brazilian agricultural soils, but important benefits can be obtained from calcium and magnesium silicates. The aim of this study was to compare the effect of neutralizing soil acidity by application of lime and silicate, with incubation of the correctives in soil conditions more or less moisture. The experiment was conducted in the Soil Chemical Analysis Laboratory at the UNOESTE, using soil collected in the layer 0-20 cm of a Sandy Loam Argisol. The experiment was carried out in a completely randomized in a 2x2x5 factorial scheme, with two correctives (lime and silicate of Ca and Mg), two soil moistures (80 and 20% moisture soil saturation) and five times (60, 90, 120, 150 and 180 days after incubation) of soil chemical properties. It was submitted to variance analysis and the effects of soil moisture and correctives were evaluated by Tukey test (p<0,05) and the incubations time were evaluated by regression analysis. The silicate has a higher neutralizing capacity of soil acidity than lime, and thus its dosage should be further investigated, because the use of the calculation to determine the lime requirement can overestimate the need for silicate applied. The lime reactivity in the soil is not influenced with soil moisture between 20 and 80% moisture saturation, unlike silicate, which has its soil reactivity enhanced in the condition of higher moisture. The soil corrective action acidity by both corrective remains increasing up to 180 days of incubation, however, satisfactory results are already obtained with 60 days of soil incubation.(AU)

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