Avaliação de bactérias nitrificantes em filtros biológicos submersos aerados

This study investigates a new treatment system of wastewater by anaerobic and aerobic biological filters for nitrogen modification. The main objective of this study was evaluate, on a pilot scale, quantitatively and qualitatively the bacterian nitrifying community in a experimental sewage treatment system made by aerobics biological filters in series, in search of figure out the dynamic of nitrogen modification process. It was collected and laboratorial analysed microbiologically, regarding NMP of Nitrosomonas e Nitrobacter, and physical-chemically considering nitrogen sequence. We conclude that: the association in aerobic biological filters under nutrition controlled conditions and oxygen level allows the appearance of bacterian community responsible for the nitrogen modification; the method used, despite its limitations, provided the selection of autotrophic nitrifying microorganisms, allowing the identification of Nitrosomonas and Nitrobacter; the flow direction tested in the experimental unit did not affect the nitrifying bacterial community, certainly because they were kept drowned and did not occur flow speed that could breake the formed biomass; the nitrification process happened in aerated biological filters in all phases of the research, comproved by microbiological tests; in the third phase of the research the increase of the oxygen rate was significant for the nitrificant bacterian community in the aerate biological filters, allowing its growth, occurring relation between the efficiency of nitrification system and the quantity of organisms responsible for this process; the conduit used in aerated biological filters showed satisfactory performance support material to the nitrifying bacteria development

Avaliação das barragens subterrâneas no regime de um curso d água na região do semi-árido do RN

The Serido is a region of northeastern Brazil highlighted by its problems related to water scarcity because of its semi-arid region, large rates of evaporation and rainfall irregular and scarce. Thus, the underground dams, become a strategically important resource with a simple and inexpensive technique for storage of water. They act in a positive way in the development of inland cities that suffer from drought, because in addition to exercise a great improvement in the social role of these families, can enjoy the type of soil (silt) and provides water for both irrigation and for human consumption throughout the year. Is therefore essential to its monitoring and studies to assess its effectiveness in accordance with its purposes, along with their wells Amazons, as can occur in conditions of physical degradation, chemical and microbiological appropriate, according to the Ordinance No 518/04 Ministry of Health, however, the proposed work aims to analyze the underground dams in the municipality of Sierra Negra North-RN (semi-arid region) as to their uses and their influences on the quality and quantity of water in periods of drought and rain. Analyzing monthly these parameters: determination of pH, conductivity, calcium, magnesium, sodium, potassium, chloride, sulfate, RAS (sodium adsorption ratio), turbidity, total iron, nitrite, nitrate, total dissolved solids (STD), bicarbonate (HCO3), fecal coliform and pesticides compared to the standards allowed by the Ordinance in force for quality for human consumption. While at the risk of salinity and sodicity on the model proposed by the United Salinity Laboratory (USSL). Although efficient, it was found that results varied annually on water quality which may influence their specific uses, whether or irrigation water supply in the city

Avaliação da qualidade final de efluentes de lagoas de estabilização com vistas ao reúso urbano

Stabilization pond is the most used sewage treatment system in the country, corresponding to approximately 90% of all systems. The systems evaluated were stabilization ponds system of sewage treatment in the city of Natal / RN. This research aimed to analyze the possible uses through physical-chemical and bacteriological of these final effluent ponds for urban uses depending on the characteristics after passage around the treatment system. The parameters used were chosen according to those established by Chernicharo et al. (2006), in order to characterize the effluent. The parameters evaluated were: DO, temperature, pH, conductivity, organic nitrogen, ammonia, NTK, total phosphorus, and series of solid fecal coliforms. Generally, the characteristics of the effluent followed variability found in the literature. The results showed an efficiency that is technically feasible to use the effluent end of some of STPs analyzed when checked parameters alone, if fitting in unrestricted urban use, restricted use and urban land use

Deposição de A/N por sputtering não reativo

In this work we deposit via non-reactive magnetron sputtering of radio-frequency nanofilmes of nitreto of aluminum(AlN). The nanofilms aluminum nitride are semiconductors materials with high thermal conductivity, high melting point, piezoelectricity and wide band gap (6, 2 eV) with hexagonal wurtzite crystal structure, belonging to the group of new materials called III-V nitrides in which together with the gallium nitride and indium nitride have attracted much interest because they have physical and chemical properties relevant to new technological applications, mainly in microelectronic and optoelectronic devices. Three groups were deposited with thicknesses nanofilms time dependent on two substrates (glass and silicon) at a temperature of 25 ° C. The nanofilms AlN were characterized using three techniques, X-ray diffraction, Raman spectroscopy and atomic force microscopy (AFM), examined the morphology of these. Through the analysis of X-rays get the thickness of each sample with its corresponding deposition rate. The analysis of X-rays also revealed that nanofilms are not crystalline, showing the amorphous character of the samples. The results obtained by the technique, atomic force microscopy (AFM) agree with those obtained using the technique of X-rays. Characterization by Raman spectroscopy revealed the existence of active modes characteristic of AlN in the samples

Características da carcaça e qualidade da carne de ovinos terminados em pastagens cultivadas

The objective of this study was to evaluate the quality of housing and the physical and chemical characteristics of meat from sheep raised on pasture Brachiaria brizantha and Panicum maximum. The experiment was conducted in the physical area of the Study Group on Forage (GEFOR), located in the Academic Unit Specialized in Agricultural Sciences - Federal University of Rio Grande do Norte - UFRN in Macaíba, RN, Brazil. We used 32 lambs SPRD, obtained from herds in the state, with liveweight (LW) of 24.5 kg were assigned randomly to four treatments consisting of tropical grasses, two cultivars of Brachiaria brizantha, Marandu and Piatã, and two of Panicum maximum, Aruana and Massai. The experimental area was 2.88 ha, divided into 4 paddocks of 0.72 ha, where each picket consisted of a farm and was divided into six plots of 0.12 ha, where the animals remained under rotational grazing. The period of adaptation to the pickets was seven days. At the beginning of the experiment the animals were weighed, identified with plastic earrings and necklaces colored according to the treatment, and treated against. The lambs were loose in the paddock at 8 am and collected at 16 hours, which returned to collective pens. During the time of grazing animals had free access to mineral supplement with monensin Ovinofós ® and water. Before entering the paddocks of pasture were sampled to characterize the chemical composition. Every seven days occurred at weighing, with fasting, to monitor the weight development. Cultivars Marandu, Aruana, Piatã and Massai were grazed for 133, 129, 143 and 142 days, respectively, until the lambs reach slaughter weight. Arriving at 32 kg lambs were evaluated subjectively for body condition score by, passed through fasting period, diet and water for 16 hours were slaughtered. Measurements were made in the inner and outer casings in addition to subjective evaluations regarding muscling, finish and quantity of pelvic-renal fat, then each was divided longitudinally into two half-carcases and cuts were made in the commercial left half, and after heavy calculated their income. Between the 12th and 13th thoracic vertebrae, was performed a cut to expose the cross section of the Longissimus dorsi, which was drawn on the rib eye area (REA) in transparent film. Fat thickness and extent of AOL GR were determined using a caliper. A tissue composition was determined by dissection of the legs. Analyzes were performed physical (color, cooking loss and shear force) and chemical composition of meat (moisture, ash, protein and lipids) in Longissimus dorsi muscle. Grazing tropical grass Brachiaria brizantha cvs. Marandu and Piatã and Panicum maximum cvs. Aruana and Massai can be used for lambs SRPD in the rainy season, because not alter the physico-chemical and chemical composition of meat

Hidróxidos duplos lamelares aplicados à obtenção de biodiesel

In this paper, the Layered Double Hydroxides (LDH s) type hydrotalcite were synthesized, characterized and tested as basic heterogeneous catalysts for the production of biodiesel by transesterification of sunflower oil with methanol. The synthesis of materials Layered Double Hydroxides (LDH s) by co-precipitation method from nitrates of magnesium and aluminum, and sodium carbonate. The materials were submitted to the variation in chemical composition, which is the amount of Mg2+ ions replaced by Al3+. This variation affects the characteristic physico-chemical and reaction the solid. The molar ratio varied in the range of 1:1 and 3:1 magnesium / aluminum, and their values between 0.2 and 0.33. This study aims to evaluate the influence of variation of molar ratio of mixed oxides derived from LDH s and the influence of impregnation of a material with catalytic activity, the KI, the rate of conversion of sunflower oil into methyl esters (biodiesel) through transesterification by heterogeneous catalysis. .The catalysts were calcined at 550 ° C and characterized by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy of X-ray (SEM / EDS), thermogravimetric analysis (TG) and test basicity. The transesterification reaction was performed for reflux is a mixture of sunflower oil and methanol with a molar ratio of 15:1, a reaction time of 4h and a catalyst concentration of 2% by weight. The physical-chemical characterization of sunflower oil and biodiesel obtained by the route methyl submitted according NBR, EN, ASTM. Subsequently, it was with the chromatographic and thermogravimetric characterizations of oils. The results of chromatographic analysis showed that the catalysts were effective in converting vegetable oil into biodiesel, in particular the type hydrotalcite KI-HDL-R1, with a conversion of 99.2%, indicating the strong influence of the chemical composition of the material, in special due to presence of potassium in the structure of the catalyst

Avaliação da estabilidade térmica e oxidativa dos biodieseis de algodão, girassol, dendê e sebo bovino

The search for new sources of environmentally friendly energy is growing every day. Among these alternative energies, biodiesel is a biofuel that has had prominence in world production. In Brazil, law 11.097, determine that all diesel sold in the country must be made by mixing diesel/biodiesel. The latter called BX, , where X represents the percent volume of biodiesel in the diesel oil, as specified by the ANP. In order to guarantee the quality of biodiesel and its mixtures, the main properties which should be controlled are the thermal and oxidative stability. These properties depend mainly of the chemical composition on the raw materials used to prepare the biodiesel. This dissertation aims to study the overall thermal and oxidative stability of biodiesel derived from cotton seed oil, sunflower oil, palm oil and beef tallow, as well as analyze the properties of the blends made from mineral oil and biodiesel in proportion B10. The main physical-chemical properties of oils and animal fat, their respective B100 and blends were determined. The samples were characterized by infrared and gas chromatography (GC). The study of thermal and oxidative stability were performed by thermogravimetry (TG), pressure differential scanning calorimeter (PDSC) and Rancimat. The obtained biodiesel samples are within the specifications established by ANP Resolution number 7/2008. In addition, all the blends and mineral diesel analyzed presented in conformed withthe ANP Regularion specifications number 15/2006. The obtained results from TG curves data indicated that the cotton biodiesel is the more stable combustible. In the kinetic study, we obtained the following order of apparent activation energy for the samples: biodiesel from palm oil > sunflower biodiesel > tallow biodiesel > cotton biodiesel. In terms of the oxidative stability, the two methods studied showed that biodiesel from palm oil is more stable then the tallow. Within the B100 samples studied only the latter were tound to be within the standard required by ANP resolution N° 7. Testing was carried out according to the EN14112. This higher stability its chemical composition

Estudo da água produzida em diferentes zonas de produção de petróleo, utilizando a hidroquímica e a análise estatística de parâmetros químicos

Over exploitation of oil deposits on land onshore or offshore, there is simultaneous generation of waste water, known as produced water, which represents the largest waste stream in the production of crude oil. The relationship between the chemical composition of oil and water production and the conditions in which this process occurs or is favored are still poorly studied. The area chosen for the study has an important oil reserve and an important aquifer saturated with freshwater meteoric. The aim of this work is to study some chemical parameters in water produced for each reservoir zone of production in mature oil fields of Açu Formation, using the hydrochemical and statistical analysis to serve as a reference and be used as tools against the indicator ranges water producers in oil producing wells. Samples were collected from different wells in 6 different areas of production and were measured 50 parameters, which can be classified into three groups: anions, cations and physicochemical properties (considering only the parameters that generated values above detection limits in all samples). Through the characterization hydrochemistry observed an area of water and chlorinated sodium, chlorinated calcium or magnesium (mixed) in well water in different areas of Açu, by applying a statistical treatment, we obtained a discriminant function that distinguishes chemically production areas. Thus, it was possible to calculate the rate of correct classification of the function was 76.3%. To validate this model the accuracy rate was 86%

Avaliação da síntese e caracterização de zeólita ZSM-5 ausente de direcionador orgânico estrutural

The catalytic processes play a vital role in the worldwide economy, a business that handles about US$ 13 billion per year because the value of products depends on the catalytic processes, including petroleum products, chemicals, pharmaceuticals, synthetic rubbers and plastics, among others. The zeolite ZSM-5 is used as catalyst for various reactions in the area petrochemical, petroleum refining and fine chemicals, especially the reactions of cracking, isomerization, alkylation, aromatization of olefins, among others. Many researchers have studied the hydrothermal synthesis of zeolite ZSM-5 free template and they obtained satisfactory results, so this study aims to evaluate the hydrothermal synthesis and the physicochemical properties of ZSM-5 with the presence and absence of template compared with commercial ZSM-5. The methods for hydrothermal synthesis of zeolite ZSM-5 are of scientific knowledge, providing the chemical composition required for the formation of zeolitic structure in the presence and absence of template. Samples of both zeolites ZSM-5 in protonic form were obtained by heat treatment and ion exchange, according to procedures reported in the literature. The sample of commercial ZSM-5 was acquired by the company Sentex Industrial Ltda. All samples were characterized by XRD, SEM, FTIR, TG / DTG / DSC, N2 adsorption and desorption and study of acidity by thermo-desorption of probe molecule (n-butylamine), in order to understand their physicochemical properties. The efficiency of the methods applied in this work and reported in the literature has been proved by well-defined structure of ZSM-5. According as the evaluation of physicochemical properties, zeolite ZSM-5 free template becomes promising for application in the refining processes or use as catalytic support, since its synthesis reduces environmental impacts and production costs

Obtenção de biodiesel através da transesterificação do óleo de farelo de arroz utilizando KI/Al2O3

This study proposes to find a biodiesel through transesterification of rice bran oil with KI/Al2O3 checking the influence of two types of alumina (Amorphous and Crystalline) for conversion into methyl esters. The catalyst was synthesized by the wet impregnation method. Adding 30 mL of 35% KI(aq.) in 10 g of alumina, under stirring at 80 °C for 3 hours. The reaction conditions used in this study were optimized, with a molar ratio methanol:oil of 15:1, 8 h of reaction time and reflux temperature. The catalyst amount was varied in the range of 1 to 5 % wt. The solid catalysts materials were analyzed by: x-ray diffraction (XRD), thermogravimetry (TG), N2 adsorption/desorption, scanning electron microscopy (SEM) and basicity, for the identification of its structure and composition, verifying the presence of basic sites. The results showed that Al2O3(A) presents an amorphous structure, high surface area and a better catalytic activity, in relation to the catalyst synthesized with Al2O3(C) support that proved to have a more crystalline structure, having as well, a lesser surface area, enabling difficulties for the incorporation of active sites. The obtained biodiesel with 5% wt. KI/Al2O3(A) presented physicochemical properties within the standards specified by the Resolution No 7/2008 ANP and obtained the best reaction yield with 95.2%, according to quantitative measurement from the TG, which showed 96.2% conversion into methyl esters. It was furthermore found that with the increasing amount of the quantity of the catalyst in the reaction, there was also an increase in the ester content obtained. The specific mass and the kinematic viscosity were reduced with the increase of the amount of quantity of the catalyst, indicating an increase in the conversion of triglycerides

Influência da acrilamida e da poliacrilamida em sistema microemulsionado visando aplicação na recuperação avançada de petróleo

This work aims to study the influence of two additives, the monomer, acrylamide and its polymer, polyacrylamide, solubilized in microemulsion systems and applied on enhanced oil recovery. By the microemulsion system obtained, it was chosen points into the phase diagram, presenting these compositions: 25%, 30%, 35% C/T; 2% Fo (fixed for all points) e 73%, 68% e 63% Fa, respectively. However, the monomer and the polymer were solubilized in these microemulsion points with 0.1%; 0.5%; 1% e 2% of concentration, ordering to check the concentration influence at the physicochemical properties (surface tension and rheology) of the microemulsion. Through the salinity study, was possible to observe that the concentrations of 1% and 2% of polymer made the solution became blurred, accordingly, the study of surface tension and rheology only was made for the concentrations of 0.1% e 0.5% of monomer and polymer, respectively. By the surface tension study it was observed that how the concentration of active matter (C/T) was increasing the surface tension was amending for each system, with or without additives. In the rheology study, as it increases the concentration of active matter increases both the viscosity of the microemulsion system (SME) with no additive, as the SME with polymer (AD2). After the entire study, it was chosen the lower point of active matter (25% C/T; 2% Fo e 73% Fa), plus additives in concentrations of 0.1% and 0.5% to be used on enhanced oil recovery. Assays were made on sandstone from Botucatu Formation, where after the tests, it was concluded that among the studied points, the point who showed the best efficiency of advanced shift was the microemulsion system + 0.5% AD2, with a recovery of 28% of oil in place and a total of 96,49%, while the other solution with 0.5% of polymer presented the worst result, with 14.1% of oil in place and 67,39% of efficiency of total displacement

Novas formulações de fluidos de corte: otimização, propriedades e recuperação do óleo usado

Cutting fluids are lubricants used in metal-mechanical industries. Their complex composition varies according to the type of operation carried out, also depending on the metals under treatment or investigation. Due to the high amount of mineral oil produced in Northeastern Brazil, we have detected the need to better use this class of material. In this work, two novel formulations have been tested, both based on naphthenic mineral oil and additives, such as: an emulsifying agent (A), an anticorrosion agent (B), a biocide (C) and an antifoam agent (D). Each formulation was prepared by mixing the additives in the mineral oil at a 700-rpm stirring velocity for 10 min, at 25°C, employing a 24 factorial planning. The formulations were characterized by means of density, total acid number (TAN), viscosity, flash point and anticorrosion activity. In a subsequent study, oil-in-water emulsions were prepared from these novel formulations. The emulsions were analyzed in terms of stability, corrosion degree, percentage of foam formation, conductivity, accelerated stability and particle size. The samples were appropriately labeled, and, in special, two of them were selected for featuring emulsion properties which were closer to those of the standards chosen as references (commercial cutting oils). Investigations were undertaken on the ability of NaCl and CaCl2 to destabilize the emulsions, at concentrations of 2%, 5% and 10%, at an 800-rpm stirring velocity for 5 min and temperatures of 25º, 40º, 50º and 60ºC. The recovered oils were chemically altered by reincorporating the same additives used in the original formulations, followed by preparation of emulsions with the same concentrations as those of the initial ones. The purpose was to assess the possibility of reusing the recovered oil. The effluents generated during the emulsion destabilization step were characterized via turbidity index, contents of oil and grease, pH, and contents of anions and cations, observing compliance with the parameters established by the current environmental legislation (Brazil s CONAMA 357/05 resolution). It could be concluded that the formulations presented excellent physicochemical properties as compared to commercial cutting fluids, showing that the quality of the newly-prepared fluids is superior to that of the formulations available in the market, enabling technically and environmentally-safe applications

Síntese e Caracterização de Titanatos de Cobalto e Níquel, dopados com Praseodímio, obtidos a partir da decomposição de Nitrilotriacetatos

In recent years, studies about the physicochemical properties of mixed oxides, call attention of the scientific community, properties like as piezoelectricity, photoluminescence, or applications as catalysts, arise in these compounds, when their chemical compositions are modified, in this context some routes are employed in the synthesis of these materials, among which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional routes or chemical routes. In this work were synthesized oxides with variable composition, from the thermal decomposition of titanium, cobalt, nickel and praseodymium nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR), Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy (FTIR). From FTIR data, it was demonstrated that the displacement of the band corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid (H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g). By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By fluorimetry was observed that the intensity of emission bands are directly proportional to the concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides, demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the complete decomposition of the nitrilotriacetates in oxides

Estudos de adsorção de tetraciclina e cromoglicato em partículas de quitosana

Among the polymers that stand out most in recent decades, chitosan, a biopolymer with physico-chemical and biological promising properties has been the subject of a broad field of research. Chitosan comes as a great choice in the field of adsorption, due to their adsorbents properties, low cost and abundance. The presence of amino groups in its chain govern the majority of their properties and define which application a sample of chitosan may be used, so it is essential to determine their average degree of deacetylation. In this work we developed kinetic and equilibrium studies to monitor and characterize the adsorption process of two drugs, tetracycline hydrochloride and sodium cromoglycate, in chitosan particles. Kinetic models and the adsorption isotherms were applied to the experimental data. For both studies, the zeta potential analyzes were also performed. The adsorption of each drug showed distinct aspects. Through the studies developed in this work was possible to describe a kinetic model for the adsorption of tetracycline on chitosan particles, thus demonstrating that it can be described by two kinetics of adsorption, one for protonated tetracycline and another one for unprotonated tetracycline. In the adsorption of sodium cromoglycate on chitosan particles, equilibrium studies were developed at different temperatures, allowing the determination of thermodynamic parameters

Estudos de adsorção de tetraciclina em partículas de quitosana

Due to its physico-chemical and biological properties, related to the abundance and low cost of raw material, chitosan has been recognized as a material of wide application in various fields, such as in drug delivery systems. Many of these properties are associated with the presence of amino groups in its polymer chain. A proper determination of these amino groups is very important, in order to properly specify if a given chitosan sample can be used in a particular application. Thus, in this work, initially, a comparison between the determination of the deacetylation degree by conductometry and elemental analysis was carried out using a detailed analysis of error propagation. It was shown that the conductometric analysis resulted in a simple and safe method for the determining the degree of deacetylation of chitosan. Subsequently, experiments were performed to monitor and characterize the adsorption of tetracycline on chitosan particles through kinetic and equilibrium studies. The main models of kinetics and adsorption isotherms, widely used to describe the adsorption on wastewater treatment systems and the drug loading, were used to treat the experimental data. Firstly, it was shown that an apparent linear t/q(t) × t relationship did not imply in a pseudo-second-order adsorption kinetics, differently of what has been repeatedly reported in the literature. It was found that this misinterpretation can be avoided by using non-linear regression. Finally, the adsorption of tetracycline on chitosan particles was analyzed using insights obtained from theoretical analysis, and the parameters generated were used to analyze the kinetics of adsorption, the isotherm of adsorption and to ropose a mechanism of adsorption