5 research outputs found

    Decolorization of anthraquinonic dyes from textile effluent using horseradish peroxidase: Optimization and kinetic study

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    Two anthraquinonic dyes, C.I. Acid Blue 225 and C.I. Acid Violet 109, were used as models to explore the feasibility of using the horseradish peroxidase enzyme (HRP) in the practical decolorization of anthraquinonic dyes in wastewater. The influence of process parameters such as enzyme concentration, hydrogen peroxide concentration, temperature, dye concentration, and pH was examined. The pH and temperature activity profiles were similar for decolorization of both dyes. Under the optimal conditions, 94.7% of C.I. Acid Violet 109 from aqueous solution was decolorized (treatment time 15 min, enzyme concentration 0.15 IU/mL, hydrogen peroxide concentration 0.4 mM, dye concentration 30 mg/L, pH 4, and temperature 24Ā°C) and 89.36% of C.I. Acid Blue 225 (32 min, enzyme concentration 0.15 IU/mL, hydrogen peroxide concentration 0.04 mM, dye concentration 30 mg/L, pH 5, and temperature 24Ā°C). The mechanism of both reactions has been proven to follow the two substrate ping-pong mechanism with substrate inhibition, revealing the formation of a nonproductive or dead-end complex between dye and HRP or between Hand the oxidized form of the enzyme. Both chemical oxygen demand and total organic carbon values showed that there was a reduction in toxicity after the enzymatic treatment. This study verifies the viability of use of horseradish peroxidase for the wastewaters treatment of similar anthraquinonic dyes

    DEVER DE FUNDAMENTAƇƃO NO NOVO CƓDIGO DE PROCESSO CIVIL E OS PRECEDENTES VINCULANTES

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    O novo CPC instituiu um modelo de precedentes vinculantes, com aproximaĆ§Ć£o do sistema jurĆ­dico dos paĆ­ses da common law. O legislador jĆ” vinha buscando a transformaĆ§Ć£o do STF e do STJ de cortes superiores em cortes supremas, com a transiĆ§Ć£o do exercĆ­cio da funĆ§Ć£o de controle do julgamento no caso concreto para a garantia de uniformidade da intepretaĆ§Ć£o do direito. Assume, entĆ£o, especial importĆ¢ncia o dever de fundamentaĆ§Ć£o, que vem disciplinado no seu artigo 489, permitindo o manejo do sistema de vinculaĆ§Ć£o, com a adequada formaĆ§Ć£o e aplicaĆ§Ć£o dos precedentes. Procura-se, pois, lanƧar luzes sobre conceitos inerentes ao trabalho com precedentes obrigatĆ³rios, sobretudo, sobre aqueles incutidos na ordem jurĆ­dica pelo novo CPC, que se tratam da ratio decidendi, do distinguishing e do overruling
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