Conciliação entre modelos de mecanismos avançados de oxidação eletroquímica

Many pollutants dumped in waterways, such as dyes and pesticides, have become so ubiquitous that they represent a serious threat to human health. The electrochemical oxidation is presented as an alternative clean, efficient and economic degradation of wastewater containing organic compounds and a number of advantages of this technique is to just not make use of chemical reagents, since only electrical energy is consumed during the removal of pollutants organic. However, despite being a promising alternative, still needs some tweaking in order to obtain better efficiency in the elimination of persistent pollutants. Thus, this study sought a relationship between a recently discovered phenomenon that reflects the participation of dissolved oxygen in solution in the electrochemical oxidation process, as an anomaly, present a kinetic model that shows instantaneous current efficiency (ICE) above 100% limited by theory, manifested for some experiments with phenolic compounds with H2SO4 or HClO4 as supporting electrolyte with electrodes under anodic oxidation on boron doped diamond (BDD). Therefore it was necessary to reproduce the data ICE exposes the fault model, and thus the 2-naphthol was used as phenolic compound to be oxidised at concentrations of 9, 12 and 15 mmol L-1, and H2SO4 and HClO4 to 1 mol L-1 as a supporting electrolyte under a current density of 30 mA cm-2 in an electrochemical reactor for continuous flow disk configuration, and equipped with anodes DDB at room temperature (25 oC). Experiments were performed using N2 like as purge gas for eliminate oxygen dissolved in solution so that its influence in the system was studied. After exposure of the anomaly of the ICE model and investigation of its relationship with dissolved O2, the data could be treated, making it possible for confirmation. But not only that, the data obtained from eletranálise and spectroscopic analysis suggest the involvement of other strongly oxidizing species (O3 (ozone) and O radicals and O2 -), since the dissolved O2 can be consumed during the formation of new strong oxidizing species, not considered until now, something that needs to be investigated by more accurate methods that we may know a little more of this system. Currently the performance of the electrocatalytic process is established by a complex interaction between different parameters that can be optimized, so it is necessary to the implementation of theoretical models, which are the conceptual lens with which researchers see

Evolução espaço-temporal da ocupação urbana sobre áreas naturais no município de Natal-RN

In this work the landscape morphodynamics was used to check the strength and importance of the changes carried out by man on the environment over time, in Natal-RN municipality. The occupation of partially preserved natural areas was analyzed, but environmentally fragile, such as riparian forests, vegetation on the banks of waterways, which play regulatory role of the water flow, and the dunes, which guarantee the rapid recharge of aquifers. The impacts of urban sprawl in Natal Southern and West zones Were identified and characterized, through a detailed mapping in the period between 1969 and 2013 the main Permanent Preservation Areas - PPA (banks of rivers and lagoons, and dunes remaining) and their temporal changes. For this were used aerial photographs and satellite imagery, altimetry data, and pre-existing information, which allowed the creation of a spatial database, and evolution of maps of impervious areas, evolution of the use and occupation and Digital Terrain Model (DTM) from contour lines with contour interval of 1 meter. Based on this study presents a diagnosis of the environmental situation and the state of conservation of natural areas, over the last 44 years, compared to human pressures. In general, it was found that the urban settlement has advanced about 60% of studied natural areas. This advance was growing by the year 2006, when there was a slowdown in the process, except for the Environmental Protection Zone (EPZ) 03, where the river Pitimbú and your PPA, which experienced a more significant loss area. The urban occupation affected the natural drainage and contributed to the contamination of groundwater Natal, due to increased sealed area, the release of liquid and solid waste, as well as the removal of riparian vegetation. Changed irreversibly the natural landscape, and reduced the quality and quantity of water resources necessary for the population. Thus, it is necessary to stimulate the adoption of use and protection of PPA planning measures, to the preservation of the San Valley Region inserted into the EPZ 01, and integrate more remaining dunes, in good condition, this EPZ, due to the importance of those remaining on the environment and the maintenance of quality of life. It is suggested, also, protection of catchment areas, such as PPA ponds and Pitimbú River. Finally, it is expected that this study can assist the managers in making decisions in urban and environmental planning of the municipality

Água residuária da mandioca como fertilizante orgânico em pasto de Brachiaria brizantha cv. Marandu

Brazil is the world's second largest producer of cassava, which most of the production is used to make flour and starch, generating large amounts of waste, cassava. In general, this waste is disposed of directly into the soil and waterways, causing serious environmental impacts. In view of this, the aim of this work was to evaluate the use of cassava wastewater water (cassava) as organic fertilizer in Brachiaria brizantha pasture. Marandu. The experiment was conducted at the Campus Macaíba the Federal University of Rio Grande do Norte. The treatments were increasing rates of cassava, applied to the soil as organic fertilizer. The experimental design was a randomized block design with six treatments and four replications. The treatments consist of cassava doses (0, 15, 30, 60 and 120 m³ ha- 1 ) and a treatment with mineral fertilizer (AM) in the form of NPK (140: 30: 120 kg ha-1 ). Three cuts with an interval of 60 days were carried out. The variables evaluated were: plant height; accumulation of morphological components of fodder; Trapping Light (IL); Leaf Area Index (LAI); Total chlorophyll (CT); Feature Production Seca (PMS). The dry matter production at a dose of 120 m³ha-1 had a quantitative increase, with a total production in 2796 kg ha-1 DM in the second cut, providing an increase of 493% compared to control, and the residual effect observed in the third cut caused a 100% increase compared to 0 m³ ha-1 . Comparing the PMS obtained with the use of AM and other treatments it was observed that it was the second cut equivalent to a dose of 120 m³ ha-1 and the third equivalence has been cut at doses 60 and 120 m³ha-1. For the variables plant height, IL, IAF, CT and leaves Mass adding cassava in the soil promoted a positive linear increase for the three cuts. However, with the AM the IAF was superior to the other treatments. The thatched mass reached its highest production (838 kg ha-1 DM) in the second cut when using a dose of 120 m³ha-1 . In dead material mass in the second and third sections, there was increased linearly increased total of 322 and 452% respectively, compared to a dose of 0 m³ha-1 . The use of cassava showed herbicidal effect for the variable mass of the undesirable negative linear response resulting in decreasing the amount of residue with increasing doses. Manipueira can be used as organic fertilizer in Brachiaria brizantha cv. Marandu for improvements in the productive characteristics, as promoted significant increases in 8 most of the variables studied, especially at a dose of 120 m³ha-1 . This benefits the environment by being alternative for disposal of cassava.