O presente trabalho teve como objetivo avaliar a eficiência da aplicação de coagulante natural à base de tanino (Tanfloc SG) em relação à aplicação de coagulantes inorgânicos (sulfato de alumínio, ...policloreto de alumínio e cloreto férrico) no tratamento de efluente líquido de laticínio. Para tanto, foram realizados testes independentes de coagulação de dois efluentes, avaliando as concentrações mínimas necessárias de cada coagulante para floculação. Na sequência foi avaliada a coagulação-floculação simples a partir da concentração mínima encontrada dos coagulantes. As análises mostraram que os tratamentos geraram um efluente pós-tratamento que atende os padrões estabelecidos pela legislação para lançamento em corpos hídricos, exceto pelo ajuste necessário do pH para algumas amostras coaguladas com cloreto férrico e sulfato de alumínio. Foram observadas diminuições de cor e turbidez (~99%), para todos os coagulantes utilizados. Para o carbono orgânico total e nitrogênio total, verificou-se reduções mais efetivas para o tanino e o policloreto de alumínio, entre 80 e 90%, respectivamente. Os coagulantes foram comparados posteriormente quanto à viabilidade econômica a partir do custo por m³, trazendo o tanino como de menor valor. Portanto, com base nos resultados encontrados, o tanino se apresenta como uma alternativa mais barata, viável e eficaz de tratamento de efluente de laticínios em comparação aos coagulantes químicos, além de causar menor dano ao meio ambiente por ser de origem natural, sendo considerado sustentável.
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Pectinase was immobilized in situ using rigid polyurethane foam as support.The strategy of immobilization was simple, facile and low cost.The immobilized pectinase showed optimal ...catalytic conditions at pH 4.5 and 55°C.Thermal and storage stabilities of immobilized enzyme were greatly enhanced.Immobilized pectinase with good capacity of reuse for hydrolysis of citric pectin.
The commercial pectinase (Rohapect® DA6L) from Aspergillus niger was successfully in situ immobilized in rigid polyurethane foam (RFPU), achieving a yield of immobilization of 178.64%. The optima reaction conditions for free and immobilized pectinase were pH 3.5 and 37°C and pH 4.5 and 55°C, respectively. During the evaluation of storage stability of immobilized derivative at 4°C, a hyperactivation of enzyme activity was observed, with an increase of 98% on the initial activity after 229 days of storage. The study of thermal stability showed that the immobilization exerted a protective effect to the enzyme submitted to high temperatures, probably due to a result of the microenvironment created inside the RFPU. The kinetic parameters showed that the immobilization process did not change the affinity of the enzyme by the substrate. The immobilized pectinase in RFPU was reused consecutively by 6 catalytic cycles in the hydrolysis of pectic oligosaccharides, keeping 35% of its initial activity. Due to the good performance of the enzymatic derivative, this presents a potential alternative to be used in the conception of industrial reactors.
In this study the interference of potassium phosphate, sodium citrate, sodium chloride and sodium nitrate salts on protein quantification by Bradford's method was assessed. Potassium phosphate and ...sodium citrate salts are commonly used in aqueous two-phase systems for enzyme purification. Results showed that the presence of potassium phosphate and sodium citrate salts increase the absorbance of the samples, when compared with the samples without any salt. The increase in absorptivity of the solution induces errors on protein quantification, which are propagated to the calculations of specific enzyme activity and consequently on purification factor. The presence of sodium chloride and sodium nitrate practically did not affect the absorbance of inulinase, probably the metals present in the enzyme extract did not interact with the added salts.
Guabiju (Myrcianthes pungens) is a fruit that stands out for its chemical composition, especially anthocyanins, which bring health benefits and can be used as natural dyes. However, there are no ...studies comparing different methods of extracting anthocyanins from guabiju peel. The objective of this work was to maximize the extraction of anthocyanins from guabiju peels by comparing the extraction methods of maceration, assisted by ultrasound, and pressurized liquid to characterize the obtained extracts. The extracts were characterized in terms of anthocyanin content, extract yield and productivity, soluble solids, color, acidity, total phenolic compounds, flavonoids, antioxidant activity, and the cost analysis involved in each methodology. The maximized conditions were absolute ethanol pH 1.0, fractional extraction (240 min) with solvent renewal in half the extraction time, 60 °C, 100 rpm of agitation in maceration, and 70 kHz by using ultrasound. The ultrasound assisted extraction method obtained the highest amount of anthocyanins (248.96 mg CE - cyanidin-3-glucoside equivalent/100 g) and an extract yield of 11.96%. For phenolic compounds and flavonoids (10,544.04 mg GAE - gallic acid equivalent/100 g and 1621.78 mg QE - quercetin equivalent/100 g), respectively, with good antioxidant capacity. Its properties and color allow for possible applications in different products. Ultrasound-assisted extraction showed a slightly lower cost of extraction than by maceration, while by PLE had a final cost approximately 2.4 times higher for 1 kg of anthocyanins.
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•Guabiju peel has a high content of anthocyanins and phenolic compounds.•Ultrasound method obtained the highest amount of anthocyanins and extract yield.•The guabiju peel extract showed good antioxidant capacity.•Its properties and color allow possible applications in different products.
O objetivo deste trabalho foi o desenvolvimento de uma metodologia acessível que permitisse a identificação qualitativa de chumbo em escória obtida em recicladoras de baterias automotivas, tendo como ...intuito oportunizar uma opção de técnica experimental para as aulas de Química Analítica Qualitativa, em que os conceitos teóricos estivessem vinculados com questões da vida real, contribuindo para um ensino mais contextualizado. Os resultados apontaram para uma metodologia simples, viável e aplicável mesmo na presença de outros íons interferentes
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