During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is thei...During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is their treatment by addition of lime and a latter pressing, obtaining a press cake and a press liquor rich in sugars (10°Brix) and citric acid, protein, pectin and ethanol. For non-thermal concentration of press liquor to obtain citruss molasses (65°-70°Brix), the removal of pectin is necessary. Traditionally, depectinization of juices has been done by using pectinmethylesterase (PME) enzymes from external sources. In this work it performed the extraction of PME enzymes from orange peels to obtain the optimum extraction conditions. Two different methods of solventextraction were compared (conventional andultrasound-assisted methods). For the conventional extraction experiments, a central composite design with three variables ([NaCl], pH and time) and five replicates of the center point was used. For ultrasound-assisted extraction, experiments were done at pH = 5.5 and [NaCl] = 1.25M), varying extraction time (1-30 min). Response variables were PME activity, protein content and a ratio between them, named PME effectiveness (ηPME). At the same experimental conditions (pH =5.5, [NaCl] = 1.25 M, t = 15 min) it was found that conventional extractions led to slightly better results in terms of ηPME than ultrasound-assisted extraction method.展开更多
During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the envir...During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the environment. The use of ozone in wastewater treatment results of interest. In this work we propose to assess the discoloration rate of different synthetic wastewaters as a function of pH, dye concentration (methylene blue (MB)) and reaction time. A comparison of discoloration rate between conventional ozonation and catalytic ozonation salts of copper, zinc, silver and nickel was also performed. For the optimization of the ozonation process of colored solutions, it was used a central composite experimental design with five replicates of the center point resulting to evaluate the influence of the independent variables at different ranges of pH, [MB] and time. In the catalyst-assisted ozonation, [MB], pH and the reaction time were fixed to 100 mg/L, 5.5 and 15 min, respectively. The optimized experimental conditions to provide maximum discoloration were pH=3.3;[MB]=8.6 mg/L and time=74.3 min. Regarding the catalyst-assisted ozonation, it was found that CuSO4 catalyst gave better color reduction if compared with other catalysts assayed.展开更多
文摘During orange juice production, a half of fresh oranges weight is considered as production waste (peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative for the management of these wastes is their treatment by addition of lime and a latter pressing, obtaining a press cake and a press liquor rich in sugars (10°Brix) and citric acid, protein, pectin and ethanol. For non-thermal concentration of press liquor to obtain citruss molasses (65°-70°Brix), the removal of pectin is necessary. Traditionally, depectinization of juices has been done by using pectinmethylesterase (PME) enzymes from external sources. In this work it performed the extraction of PME enzymes from orange peels to obtain the optimum extraction conditions. Two different methods of solventextraction were compared (conventional andultrasound-assisted methods). For the conventional extraction experiments, a central composite design with three variables ([NaCl], pH and time) and five replicates of the center point was used. For ultrasound-assisted extraction, experiments were done at pH = 5.5 and [NaCl] = 1.25M), varying extraction time (1-30 min). Response variables were PME activity, protein content and a ratio between them, named PME effectiveness (ηPME). At the same experimental conditions (pH =5.5, [NaCl] = 1.25 M, t = 15 min) it was found that conventional extractions led to slightly better results in terms of ηPME than ultrasound-assisted extraction method.
文摘During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the environment. The use of ozone in wastewater treatment results of interest. In this work we propose to assess the discoloration rate of different synthetic wastewaters as a function of pH, dye concentration (methylene blue (MB)) and reaction time. A comparison of discoloration rate between conventional ozonation and catalytic ozonation salts of copper, zinc, silver and nickel was also performed. For the optimization of the ozonation process of colored solutions, it was used a central composite experimental design with five replicates of the center point resulting to evaluate the influence of the independent variables at different ranges of pH, [MB] and time. In the catalyst-assisted ozonation, [MB], pH and the reaction time were fixed to 100 mg/L, 5.5 and 15 min, respectively. The optimized experimental conditions to provide maximum discoloration were pH=3.3;[MB]=8.6 mg/L and time=74.3 min. Regarding the catalyst-assisted ozonation, it was found that CuSO4 catalyst gave better color reduction if compared with other catalysts assayed.
