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Effluents with dyes when released into the environment can cause damage to ecosystems, preventing access to light and thus harming various environmental processes. Thus, the aim of the present study was to carry out a literature review on the use of heterogeneous photocatalytic processes based on double lamellar hydroxide (HDL)- TiO2 composites in the treatment of wastewater with dyes. Currently, the main means for the treatment of dyes is the use of physicochemical adsorption processes, however, some dyes have high stability in the medium, making it difficult to remove them without the use of advanced processes. Advanced oxidative processes (AOPs) emerge as an effective alternative due to their high redox potential, where heterogeneous photocatalysis using TiO2 has advantages due to its excellent photocatalytic activity, lower toxicity and costs compared to other available semiconductors. Among the challenges of this process is the low adsorptive potential of TiO2, due to its low area and porosity, thus, the incorporation in clayey supports, such as hydrotalcite, becomes a possibility to improve the properties of the semiconductor and thus improve the photocatalys process. [ABSTRACT FROM AUTHOR]

Introduction: The current scenario, characterized by the growing demand for healthy and practical foods, represents an important opportunity for innovation with added value in the development of new products. Objective: This research aimed to develop a lyophilized yacon flour as a source of prebiotic ingredient and apply it in the development of a functional cookie. Materials and Methods: The study is an experimental methodology with a cross-sectional design. Three formulations were developed with different percentages of lyophilized yacon flour (40%, 50% and 60%). The sensory analysis of the three formulations was carried out by 62 tasters, using the hedonic scale of nine points, with a score varying from very disgusted to very liked. The study was approved by the Ethics and Research Committee (CEP) of the University of Vale do Rio dos Sinos (UNISINOS), under nº 80170017.6.0000.5344. Results: There was a reduction of 40%, 37.7% and 38.47% of total fats; 41.38%, 30.51% and 31.67% reduction in saturated fat; increase in the total fiber value of 240%, 200% and 170%, respectively, when compared to the initial standard cookie formulation. Regarding the sensory attributes, it is proved that, in general, there was a good acceptance of the three formulations developed in the cookie. Discussion: In comparison with the data in the literature, the product developed showed good acceptance and with a higher percentage of yacon flour. Conclusion: Lyophilized yacon flour proved to be an ingredient with high technological potential for the reduction of fats and sugars in products, in addition to containing prebiotic fibers important for intestinal health. [ABSTRACT FROM AUTHOR]

The goal of this work was to compare the use of precipitation by chemical reduction with the use of chelating resin to obtain copper present in nickel laterite leach solution. A synthetic solution was prepared to simulate the liquor obtained in ore leaching. The precipitation process was performed through reducing the redox potential of solution until 240 mV, and the reducing agent used was sodium dithionite. The effect of stirring speed was also studied for precipitation between 0 and 200 rpm. The chelating resin Lewatit TP 207, of functional group iminodiacetate, was used for ion exchange experiments. The solution was put in contact with the resin and taken a constant stirring in 200 rpm. The effect of pH was studied between 0.50 and 2.00. All experiments were performed at 25 °C and 120 min. Results indicated that the use of precipitation technique by chemical reduction was more advantageous than chelating resins. In chemical reduction, it was possible to obtain a selective precipitation of 96% of copper at pH 0.50 and 45 rpm. In experiments using chelating resins, it was possible to absorb 48% of copper at pH 2.00, and also contaminants such as iron and aluminum. [ABSTRACT FROM AUTHOR]