ABSTRACT
The present paper presents the study of (1) the optimization of electrochemical-free chlorine production using an experimental design approach, and (2) the application of the optimum conditions obtained for the application in photo-assisted electrochemical degradation of simulated textile effluent. In the experimental design the influence of inter-electrode gap, pH, NaCl concentration and current was considered. It was observed that the four variables studied are significant for the process, with NaCl concentration and current being the most significant variables for free chlorine production. The maximum free chlorine production was obtained at a current of 2.33â A and NaCl concentrations in 0.96â molâ dm-3. The application of the optimized conditions with simultaneous UV irradiation resulted in up to 83.1% Total Organic Carbon removal and 100% of colour removal over 180â min of electrolysis. The results indicate that a systematic (statistical) approach to the electrochemical treatment of pollutants can save time and reagents.
Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Chlorine , Electrolysis , Oxidation-Reduction , Research Design , Textile IndustryABSTRACT
ABSTRACT: Essential oils are the most important compounds produced during secondary metabolism in aromatic plants. Essential oils are volatile, have characteristic odor and are used as defensive agents by plants. In pepper, it is possible to say that essential oils are the “flavor fingerprint” of each species. In the present article, eight species of pepper were studied in order to extract their essential oils and oleoresins, test their antibacterial and antifungal activities and also to identify the compounds present in the most bioactive samples. Results demonstrated that two essential oils [Pimenta dioica (L.) Merr. and Schinus terebinthifolius] and three oleoresins (Schinus terebinthifolius and Piper nigrum white and black) recorded significant antimicrobial activity. These active essential oils and oleoresins are interesting for use in biotechnological processes employed in food, pharmaceutical and other industries.
RESUMO: Os óleos essenciais são os compostos mais importantes produzidos durante o metabolismo secundário de plantas aromáticas. No caso das pimentas, é possível afirmar que os óleos essenciais são a “impressão digital do sabor” de cada espécie. No presente artigo, oito espécies de pimenta foram estudadas a fim de extrair seus óleos essenciais e oleoresinas, testar a sua atividade antibacteriana e antifúngica, bem como, identificar os compostos presentes nas amostras mais ativas. Os resultados obtidos mostram que dois óleos essenciais (Pimenta dioica e Schinus terebinthifolius) e três oleoresinas (Schinus terebinthifolius e Piper nigrum branco e preto) apresentaram atividade antimicrobiana significativa. Esses óleos essenciais e oleoresinas bioativos mostram-se interessantes para a utilização em processos biotecnológicos empregados na indústria alimentar, farmacêutica e outras indústrias.