9 research outputs found

    Effect of Inorganic Additives in the Textile Dyes Removal by Ozonation

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    Treatment of industrial wastewaters based on oxidative efficiency of ozone is still of great interest due to the high removal percentages of the initial pollutants and their by-products. In particular, the industrial dyes and their wastewaters have received special attention considering the large volumes of water produced daily with high concentration of chemical oxygen demand. In addition, the dyeing processes use some chemical additives to enhance the final quality of dyeing. The effect of all these additives on the wastewater treatment has been insufficiently explored. This chapter is focused on the study of different additives commonly used in dyeing process (Na2SO4 and Na2CO3 for Reactive Black 5 – RB5, Na2SO4 at different concentrations for Direct Red 28 – DR28, and acetic acid for Basic Green 4 – BG4) and their effect on ozonation efficiency in discoloration and dye decomposition. Moreover, the distribution of by-products obtained throughout the ozonation was compared when the additives are or not participating in the reaction. The influence of additives and dyes’ chemical nature, their concentration, and the induced pH variation on dye solutions are explained using the results of ozone based on the treatment of the three dyes mentioned earlier. The characteristics of each dye combined with the corresponding additives over degradation and decomposition efficiency by ozone, and the by-product distribution was also studied

    Catalytic Ozonation as a Promising Technology for Application in Water Treatment: Advantages and Constraints

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    Freshwater pollution compromises drinking water in a worldwide context. Water pollution is one of the major environmental challenges facing humanity. Therefore, the application of methods to control the pollution in water is a growing research field. Among the methods, ozone has been widely applied due to its high oxidation potential. However, one disadvantage is the presence of refractory organic compounds that are partially oxidized leaving mineralization incomplete. Several approaches have been considered to improve the oxidizing power, reducing the reaction time, and increasing the mineralization degree of ozone. So far, the combination of a solid catalyst with ozone (catalytic ozonation) has shown to enhance the degradation of refractory organic compounds in water. This chapter presents the combination of different metallic oxides (Al2O3, TiO2, SiO2, and NiO) with ozone to determine the effect of ozone decomposition and the subsequent elimination of one chlorinated compound (2,4-D). The chemical structure of the initial compound (2,4-D, benzoic and phthalic acid), as well as the initial catalyst dosage (0.1 and 0.5 g L−1) with the mentioned compounds, was also studied. Moreover, the degradation of two aromatic compounds (naphthalene and naproxen) with different proportions of ethanol (representing the organic matter of wastewater) was analyzed to establish their effect on the catalytic ozonation process

    Autophagy and Mitophagy as Essential Components of Atherosclerosis

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    Cardiovascular disease (CVD) is one of the greatest health problems affecting people worldwide. Atherosclerosis, in turn, is one of the most common causes of cardiovascular disease. Due to the high mortality rate from cardiovascular diseases, prevention and treatment at the earliest stages become especially important. This requires developing a deep understanding of the mechanisms underlying the development of atherosclerosis. It is well-known that atherogenesis is a complex multi-component process that includes lipid metabolism disorders, inflammation, oxidative stress, autophagy disorders and mitochondrial dysfunction. Autophagy is a cellular control mechanism that is critical to maintaining health and survival. One of the specific forms of autophagy is mitophagy, which aims to control and remove defective mitochondria from the cell. Particularly defective mitophagy has been shown to be associated with atherogenesis. In this review, we consider the role of autophagy, focusing on a special type of it—mitophagy—in the context of its role in the development of atherosclerosis

    UV-assisted anchoring of gold nanoparticles into TiO2 nanotubes for oxygen electroreduction

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    Gold nanoparticles (AuNPs) have been deposited on titania nanotubular layers (TNT) via photocatalytic deposition, and the activity of the obtained AuNPs-TNT systems toward oxygen electroreduction reaction (ORR) in an alkaline medium has been studied and compared with the activity of AuNPs TNT composites prepared from Au colloidal solutions. Two photodeposition methods were utilized for anchoring of AuNPs: direct UV-irradiation of a TNT electrode immersed into a HAuCl4 containing solution (TNT-Au1 composites) and initial adsorption of AuCl4− ions on TNT followed by UV irradiation (TNT-Au2 composites). The size, spatial distribution, structure and surface of AuNPs deposited on TNT layers were studied via scanning and transmission electron microscopy, optical spectroscopy and underpotential deposition of lead ad-atoms on gold. It was found that these parameters depend on the photodeposition method. The TNT-Au2 composites have smaller size, higher surface concentration and more uniform distribution of AuNPs in the TNT layers as compared with the TNT-Au1 systems. The electrocatalytic efficiency of Au-TNT electrodes in ORR was found to depend on various factors such as doping level of TNT support (governed by annealing temperature), AuNPs size and their loading amount. The electroreduction of oxygen was observed at less negative potentials when Au nanoparticles were grown on the TNT surface by photoreduction in comparison with the TNT electrodes modified with AuNPs from sols. The enhanced activity of the photocatalytically prepared AuNPs-TNT composites can be explained by the consolidation of the interface between gold nanoparticles and TiO2 support and the absence of ligands on the AuNPs surface.publishe

    Mitochondrial Implications in Cardiovascular Aging and Diseases: The Specific Role of Mitochondrial Dynamics and Shifts

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    Cardiovascular disease has been, and remains, one of the leading causes of death in the modern world. The elderly are a particularly vulnerable group. The aging of the body is inevitably accompanied by the aging of all its systems, and the cardiovascular system is no exception. The aging of the cardiovascular system is a significant risk factor for the development of various diseases and pathologies, from atherosclerosis to ischemic stroke. Mitochondria, being the main supplier of energy necessary for the normal functioning of cells, play an important role in the proper functioning of the cardiovascular system. The functioning of each individual cell and the organism as a whole depends on their number, structure, and performance, as well as the correct operation of the system in removing non-functional mitochondria. In this review, we examine the role of mitochondria in the aging of the cardiovascular system, as well as in diseases (for example, atherosclerosis and ischemic stroke). We pay special attention to changes in mitochondrial dynamics since the shift in the balance between fission and fusion is one of the main factors associated with various cardiovascular pathologies
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