RESUMO
The degradation of a model pollutant, tartrazine, very used in food industry and usually present in WWTPs effluents and surface waters, was investigated by nine activated homogeneous catalytic processes, namely, Fe3+/H2O2, Fe2+/H2O2, UV/H2O2, UV/S2O82-, UV/Fe2+/H2O2, UV/Fe3+/H2O2, UV, VIS/Fe3+/H2O2, and VIS/Fe3+/H2O2/C2O42-. In order to compare the mineralization and oxidation ability of each process, the removal of dye, chemical oxygen demand (COD) and total organic carbon (TOC) were analyzed, as well as the overall kinetic rate constant. Also, the different oxidation path-ways (direct photolysis and/or oxidation by free radicals) were estimated for each system. After the comparison, the Fenton process, which had the highest mineralization values, was tested in luminous and dark phases using designed experiments, and the influences of all operating variables were studied by RSM.
Assuntos
Peróxido de Hidrogênio , Poluentes Químicos da Água , Catálise , Cinética , Oxirredução , Fotólise , Raios UltravioletaRESUMO
In this work, a pyrolysis plant located in Valverde de Leganes, Badajoz (SW Spain) was studied. At present, only the solid phase obtained by pyrolysis finds an application as domestic fuel. In order to analyze the feasibility of a further energetic exploitation of the plant under study, the gases flowing through the chimneys were collected at different times throughout the pyrolysis process. Next, they were characterized and quantified by gas chromatography, the energy potential of each of the gases being determined. According to the results obtained in this study, a total energy potential of 5.6 x 10(7) MJ (i.e., 1.78 MW(t)) might be generated yearly. Hence, considering an overall process yield equal to 20%, up to 358 KW(e) would be produced. This power would supply enough electric energy to the industry, the remaining being added to the common electric network.
Assuntos
Fontes de Energia Bioelétrica , Fontes Geradoras de Energia , Gases/análise , Temperatura Alta , Árvores/química , Resíduos/análise , Cromatografia Gasosa , Transição de Fase , EspanhaRESUMO
Changes in synaptic structure were examined in junctions of the retino-recipient layers of the opossum superior colliculus (SC) at critical developmental stages (30, 40 and 61 day-old pouch young and adult controls). Criteria of classification were the presence and direction of curvature (smile, flat, frown and irregular) and the degree of aggregation of paramembranous components (immature, intermediate and mature). The results favor the aggregation of dense components vis-a-vis curvature in the assessment of maturational changes.
Assuntos
Gambás/fisiologia , Retina/crescimento & desenvolvimento , Colículos Superiores/crescimento & desenvolvimento , Sinapses/fisiologia , Animais , Gambás/crescimento & desenvolvimento , Ácido Fosfotúngstico , Retina/ultraestrutura , Colículos Superiores/ultraestrutura , Sinapses/ultraestruturaRESUMO
Using commercial activated carbon as an adsorbent, the kinetics of adsorption of zinc from multicomponent ionic systems having cadmium and mercury has been studied and reported. The variables investigated have been the chemical nature, ionic strength, and pH of the adsorptive (Zn2+) solution. The adsorption of Zn2+ is speeded up by the presence of Cd2+ and Hg2+ ions provided that the concentration of these two ions is high as compared to the concentration of Zn2+. When the ionic strength of the solution in relative terms is high (i.e., > 3 x 10(-4) M), however, the adsorption of Zn2+ decelerates. Also, the adsorption process is greatly accelerated at pH 12, whereas at pH 2 it does not occur at all.
Assuntos
Cádmio/química , Mercúrio/química , Zinco/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Porosidade , Soluções/química , Propriedades de Superfície , Fatores de TempoRESUMO
BACKGROUND: Diabetes mellitus (DM) is a major risk factor for coronary artery disease, renal failure, retinopathy, and neuropathy. Over the last years, there has been an increasing demand in folk medicine for natural sources that could help in the treatment of chronic diseases, including diabetes. The rind of passion fruit (Passiflora edulis f. Flavicarpa) is traditionally used as a functional food due to its high concentration of soluble and insoluble fiber. OBJECTIVE: The aim of this study was to determine the effect of high-fiber diet albedo of passion fruit on the metabolic and biochemical profile in diabetic rats induced by alloxan (2%). DESIGN: The passion fruit mesocarp fiber was dried in an oven with circulating air at 60°C and pulverized. We used 32 adult male rats, divided into 4 groups: Wistar group 1 control (GC), Wistar group 2, 15% fiber (GF15), Wistar group 3, 30% fiber (GF30), Wistar group 4, fiber disolved in water (GFH2O). The ratio of passion fruit was prepared according to the AIN 93M guidelines, varying only the source of dietary fiber. The corresponding diet for each group was offered to the animals for 60 days. RESULTS: There was a statically significant decrease in plasma glucose for GFH2O, GF15%, and GF30% groups with 27.0%, 37.4%, and 40.2%, respectively. CONCLUSION: The use of mesocarp fiber of passion fruit at concentrations of 15% and 30% are an important dietary supplement for the treatment of DM due to its potential hypoglycemic effect, and its ability to reduce triglycerides and VLDL-cholesterol levels with a principal reduction of insulin and leptin.
RESUMO
Changes in synaptic structure were examined in junctions of the retino-recipient layers of the opossum superior colliculus (SC) at critical developmental stages (30, 40 and 61 dai-old pouch young and adult controls). Criteria of classification were the presence and direction of curvature (smile, flat, frown and irregula) and the degree of aggregation of paramembranous components vis-a-vis curvature in the assessment of maturational changes