Uso da tecnologia de troca iônica no tratamento de águas contaminadas com Nitrato do Aqüífero Dunas-Barreiras, Natal/RN-Brasil

The city of Natal comprises an area of about 170 km² (65,63 squares miles). The Dunas-Barreiras Aquifer is the most important reservoir of the coastal basin of RN. It is being responsible for the water supplying of about 70% of the population, however, due to the sewage disposal system by cesspools and drains, it is presently affected in a great extent by nitrates contamination. Thus, the present work proposes to research the utilization of contaminated water by nitrates of this fountainhead and find cost of the potable water through the ionic exchange technology. This technology consists in the removal of mineral salts by the exchange of cations for one ion of hydrogen (H+), through the passage of water by cationic resin bed and, secondly, by the exchange of the anions for hydroxyl ions (OH-) through a anionic resin bed. The obtained results have showed the waters derived from fountains, big water holes and shallow wells were microbiologically contaminated, while the waters derived from deep wells (above 70 m 76,58 yards) were free of contamination. Thus, only these ones are suitable to the use of ionic technology. The experiments were conducted with the resin IMAC-HP-555 such as kinetic, thermodynamic, and adsorption by fixed bed studies, being obtained several project variables for the experimental column, as follow: work temperature of 25oC; resin maximum capacity maximum e mean of adsorption ==0,01692 g NO3-1/g R e 0,0110 g NO3-1/g R, respectively. On the experimental column were performed breakthrough tests which pointed for an average ideal average speed of work of 13.2 m / h, with an average efficiency of 45% of adsorption, an optimal concentration of NaCl desorption of 8%, and an ideal desorption time of 80 minutes for the equilibrium conditions of water from the Dunas-Barreiras aquifer. Scale projection for ion-exchange column for denitrification, for these variables, using a computer modeling programme, to project the column of ion exchange ROREX-420/2000, obtained a cost for the drinking water denitrified by this system of R$ 0,16 / m3

Aplicação da água residuária das salinas no tratamento de efluente têxtil

The treatment of colored and alkaline effluent has been a challenge to the textile industry. An alternative to remove the colors of those effluents is applying magnesium chloride as a coagulant agent. The magnesium ion, in high pH, hydrolyzes itself, forming the magnesium hydroxide which has a large adsorptive area and positive electrostatic charges able to act as an efficient coagulant. The bittern wastewater from the salt industries has been studied as a potential font of this magnesium ion. Nowadays, this bittern wastewater is evicted into the sea, without any treatment or other use. This thesis has evaluated the potential of applying the wastewater from the salt industries in the treatment of dyeing effluent containing indigo dye and alkaline pH. All the experiments were made in jar tests simulating the chemical coagulation, flocculation and decantation steps ranging the pH and the concentration of magnesium ion. Were obtained removals between 96% and 76% for turbidity, apparent color, and true color, respectively, using 200mg/L Mg2+. The reduction of costs with acid, when were used the salt industries wastewater, comparing with Al2(SO4)3, was 62%. For the degradation of organic matter remaining in the clarified, around 900 mg/L, was applyed the advanced process of oxidation: photo-Fenton. The preliminary results showed 57% reduction in DOC. According to the results obtained, the salt industries wastewater can be applied, as coagulant, in the physical-chemical treatment of the denim dyeing wastewater, so it is not necessary a previous adjust of pH, efficiently and economically

Estudo da reidratação do feijão verde (Vigna unguiculata L. Walp) desidratado por micro-ondas com e sem pré-tratamento osmótico

The green bean has organoleptic and nutritional characteristics that make it an important food source in tropical regions such as the Northeast of Brazil. It is a cheap source of protein and important for nutrition of rural population contributing significantly in subsistence farming of the families from Brazil s northeast. It is consumed in entire region and together with the dry meat and other products composes the menu of typical restaurants, being characterized as an important product for economy of Northeast. The green bean is consumed freshly harvested and has short cycle, being characterized as a very perishable food, which hampers your market. The drying method is an alternative to increase the lifetime and provide a reduction volume of this product making easier your transportation and storage. However is necessary to search ways of drying which keep the product quality not only from the nutritional standpoint but also organoleptic. Some characteristics may change with the drying process such as the coloring, the rehydration capacity and the grains cooking time. The decrease of drying time or of exposure of the grains to high temperature minimizes the effects related with the product quality loss. Among the techniques used to reduce the drying time and improve some characteristics of the product, stands out the osmotic dehydration, widely used in combined processes such as the pretreatment in drying food. Currently the use of the microwaves has been considered an alternative for drying food. The microwave energy generates heat inside of materials processed and the heating is practically instantaneous, resulting in shorter processing times and product quality higher to that obtained by conventional methods. Considering the importance of the green beans for the Northeast region, the wastefulness of production due to seasonality of the crop and your high perishability, the proposal of this thesis is the study of drying grain by microwaves with and without osmotic pretreatment, focusing on the search of conditions of processes which favor the rehydration of the product preserving your organoleptic characteristics. Based on the analysis of the results of osmotic dehydration and dielectric properties was defined the operating condition to be used in pretreatment of the green bean, with osmotic concentration in saline solution containing 12,5% of sodium chloride, at 40°C for 20 minutes. The drying of green bean by microwave was performed with and without osmotic pretreatment on the optimized condition. The osmotic predehydration favored the additional drying, reducing the process time. The rehydration of dehydrated green bean with and without osmotic pretreatment was accomplished in different temperature conditions and immersion time according to a factorial design 22, with 3 repetitions at the central point. According to results the better condition was obtained with the osmotically pretreated bean and rehydrated at a temperature of 60°C for 90 minutes. Sensory analysis was performed comparing the sample of the green bean in natura and rehydrated in optimized conditions, with and without osmotic pretreatment. All samples showed a good acceptance rate regarding the analyzed attributes (appearance, texture, color, odor and taste), with all values above 70%. Is possible conclude that the drying of green bean by microwave with osmotic pretreatment is feasible both in respect to technical aspects and rehydration rates and sensory quality of the product

Avaliação e modelagem da absorção de H2S do gás natural em coluna de leito estagnado

Natural gas, although basically composed by light hydrocarbons, also presents contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). The H2S, which commonly occurs in oil and gas exploration and production activities, causes damages in oil and natural gas pipelines. Consequently, the removal of hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is essential to consider the better quality of the oil to be processed in the refinery, thus resulting in benefits in economic, environmental and social areas. All this facts demonstrate the need for the development and improvement in hydrogen sulfide scavengers. Currently, the oil industry uses several processes for hydrogen sulfide removal from natural gas. However, these processes produce amine derivatives which can cause damage in distillation towers, can cause clogging of pipelines by formation of insoluble precipitates, and also produce residues with great environmental impact. Therefore, it is of great importance the obtaining of a stable system, in inorganic or organic reaction media, able to remove hydrogen sulfide without formation of by-products that can affect the quality and cost of natural gas processing, transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer and kinetics of hydrogen removal, in this study it was used an absorption column packed with Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by the liquid phase. This absorption column was coupled with a H2S detection system, with interface with a computer. The data and the model equations were solved by the least squares method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride, copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low concentrations (»10 ppm). These solutions were used looking for the evaluation of the interference between absorption physical and chemical parameters, or even to get a better mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow. In this context, the evaluation of H2S removal arises as a valuable procedure for the treatment of natural gas and destination of process by-products. The study of the obtained absorption curves makes possible to determine the mass transfer predominant stage in the involved processes, the mass transfer volumetric coefficients, and the equilibrium concentrations. It was also performed a kinetic study. The obtained results showed that the H2S removal kinetics is greater for NaOH. Considering that the study was performed at low concentrations of chemical reagents, it was possible to check the effect of secondary reactions in the other chemicals, especially in the case of KMnO4, which shows that your by-product, MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to have good efficiency in H2S removal

Sistemas microemulsionados aplicados à remoção da cor de efluente têxtil

Effluent color resulting from textile dyeing processes has been one of the biggest environmental problems faced by the textile industry. In particular, reactive dyes are highly resistant to conventional wastewater treatment methods. New technologies have been contemplated, some of which have been applied in industrial treatment plants, but color removal has not been efficiently attained. Since microemulsion systems provide good results in heavy metals and proteins extraction processes, their use in dyes extraction has been suggested and investigated. In this work, a real textile wastewater from an exhaustion dyebath has been treated, which contains the following reactive dyes: Procion Yellow H-E4R (CI Reactive Yellow 84), Procion Blue H-ERD (CI Reactive Blue 160) and Procion Red H-E3B (CI Reactive Red 120), in addition to auxiliary compounds normally found in dyeing processes with reactive dyes. The dyes Remazol Blue RR and Remazol Turquoise Blue G (Reactive Blue 21) have also been examined in view of the presence of heavy metals in these molecules. The microemulsion system comprised dodecyl ammonium chloride (as a cationic surfactant), water or wastewater as aqueous phase, kerosene as oil phase, and one of the following alcohols as cosurfactant: isoamyl alcohol, n-butyl alcohol and n-octyl alcohol. The pseudo-ternary diagrams were constructed in order to define Winsor s equilibrium regions. The influence of parameters such as pH, C/S (cosurfactant/surfactant) ratio, distribution coefficient, initial dye concentration, salinity, temperature, phases relative amounts, loading capacity of the microemulsion phase and dye reextraction rate has also been investigated. An experimental planning (Scheffé Net) was used to optimize the extraction process. The removal of color and metals reached levels as high as 99%

Novas alternativas de remoção de enxofre do óleo diesel utilizando tensoativos e microemulsões

The diesel combustion form sulfur oxides that can be discharged into the atmosphere as particulates and primary pollutants, SO2and SO3, causing great damage to the environment and to human health. These products can be transformed into acids in the combustion chamber, causing damage to the engines. The worldwide concern with a clean and healthy environment has led to more restrictive laws and regulations regulating the emission levels of pollutants in the air, establishing sulfur levels increasingly low on fuels. The conventional methods for sulfur removal from diesel are expensive and do not produce a zero-level sulfur fuel. This work aims to develop new methods of removing sulfur from commercial diesel using surfactants and microemulsion systems. Its main purpose is to create new technologies and add economic viability to the process. First, a preliminary study using as extracting agent a Winsor I microemulsion system with dodecyl ammonium chloride (DDACl) and nonyl phenol ethoxylated (RNX95) as surfactant was performed to choose the surfactant. The RNX95 was chosen to be used as surfactant in microemulsioned systems for adsorbent surface modification and as an extracting agent in liquid-liquid extraction. Vermiculite was evaluated as adsorbent. The microemulsion systems applied for vermiculite surface modification were composed by RNX95 (surfactant), n-butanol (cosurfactant), n-hexane (oil phase), and different aqueous phases, including: distilled water (aqueous phase),20ppm CaCl2solution, and 1500ppm CaCl2solution. Batch and column adsorption tests were carried out to estimate the ability of vermiculite to adsorb sulfur from diesel. It was used in the experiments a commercial diesel fuel with 1,233ppm initial sulfur concentration. The batch experiments were performed according to a factorial design (23). Two experimental sets were accomplished: the first one applying 1:2 vermiculite to diesel ratio and the second one using 1:5 vermiculite to diesel ratio. It was evaluated the effects of temperature (25°C and 60°C), concentration of CaCl2in the aqueous phase (20ppm and 1500ppm), and vermiculite granule size (65 and 100 mesh). The experimental response was the ability of vermiculite to adsorb sulfur. The best results for both 1:5 and 1:2 ratios were obtained using 60°C, 1500ppm CaCl2solution, and 65 mesh. The best adsorption capacities for 1:5 ratio and for 1:2 ratio were 4.24 mg sulfur/g adsorbent and 2.87 mg sulfur/g adsorbent, respectively. It was verified that the most significant factor was the concentration of the CaCl2 solution. Liquid-liquid extraction experiments were performed in two and six steps using the same surfactant to diesel ratio. It was obtained 46.8% sulfur removal in two-step experiment and 73.15% in six-step one. An alternative study, for comparison purposes, was made using bentonite and diatomite asadsorbents. The batch experiments were done using microemulsion systems with the same aqueous phases evaluated in vermiculite study and also 20ppm and 1500 ppm BaCl2 solutions. For bentonite, the best adsorption capacity was 7.53mg sulfur/g adsorbent with distilled water as aqueous phase of the microemulsion system and for diatomite the best result was 17.04 mg sulfur/g adsorbent using a 20ppm CaCl2solution. The accomplishment of this study allowed us to conclude that, among the alternatives tested, the adsorption process using adsorbents modified by microemulsion systems was considered the best process for sulfur removal from diesel fuel. The optimization and scale upof the process constitutes a viable alternative to achieve the needs of the market

Variação da qualidade da água do escoamento superficial de duas bacias de drenagem de Natal/RN - Brasil

The urban drainage is one of the powers of environmental sanitation and its scope is the quantitative and qualitative aspects. In decision making of managers and the engineering aspects of design are almost always taken into account only the quantitative aspects. However, the waters of the runoff have the highest concentrations of pollutants at the beginning of precipitation. Thus, if the plot pollution removed, the remaining portion can be used for other purposes. This work has aimed to present the variation of water quality of two drainage basins in the city of Natal / RN-Brazil to support the implementation of drainage to consider the qualitative aspect, and identify potential for the use of water. The basins (M and C) are analyzed closed-type, are in the urban area, are predominantly residential occupation and its waters are used for detention ponds and infiltration. The samples were divided into three phases, the first two direct to final points in a basin and the third in traps distributed over the surface drainage. The parameters had been analyzed were pH, conductivity, dissolved oxygen, Color, Turbidity, COD, Ammonia, nitrite, nitrate, total phosphorus, orthophosphate, Sediments solids, total solids, chloride, sulfate, alkalinity, calcium, magnesium, sodium, potassium, Heavy Metals (Chromium, Cadmium, Lead, Zinc and Copper), Eschichia coli and total coliforms. The parameters studied showed high initial pollution load, events and located in different proportions, except nitrite, heavy metals and biological indicators. The size of the surface drainage and topographic its features influence the quality of water. However, the form of sampling is crucial in the qualitative study in the basin. The samplers developed at work, were generated economic and representative results. The urban rainwater presents organic faecal indicators. The runoff of water from both basins shows no risk of salinity and sodicity for use in irrigation, should be noted the content of chloride in the choice of method of irrigation

Influencia de la deshidratación osmótica y de la adición de cloruro de calcio en la conservación de kivis minimamente procesados

Este trabalho teve como objetivo estudar o efeito combinado da desidratação osmótica e a influência do cloreto de cálcio em rodelas de kiwi submetidas ao processamento mínimo. Amostras com e sem desidratação osmótica foram armazenadas a 5 °C em embalagem PET. A adição do cloreto de cálcio foi realizada durante a desidratação osmótica. Foram avaliados a perda de peso, acidez, sólidos solúveis, pH, umidade, coliformes, fungos e leveduras nas amostras até 15 dias de armazenamento. A avaliação microbiológica e sensorial definiu a vida de prateleira do produto. Os resultados mostraram que o pré-tratamento osmótico com adição de cloreto de cálcio aumentou a vida útil em até 15 dias, enquanto as rodelas tratadas por osmodesidratação, sem a adição do sal apresentaram vida útil de 12 dias. Sensorialmente, os consumidores preferiram as rodelas de kiwi processadas com pré-tratamento osmótico e adição de cloreto de cálcio.

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 flotação por ar dissolvido no polimento de efluentes de lagoa de estabilização

Experience in the use of stabilization ponds shows that this is a system with low cost, easy operation and maintenance and suitable for tropical countries. One of its disadvantages is due to high concentrations of suspended solids, mainly due to algal biomass in the effluents. Accordingly, the dissolved air flotation has been shown to be an efficient post-treatment technology. However, the efficiency of this process is related to coagulation and flocculation steps, as well as the adjustment of the involved variables in the process. The objective of this work was to evaluate the algae removal efficiency from wastewater stabilization ponds and the influence of the factors involved in the process using dissolved air flotation. For this, we used primary facultative and maturation effluents of ETE Ponta Negra in Natal. We did tests of coagulation, flocculation and flotation with the samples, using the equipment flotatest. In this process were tested coagulants aluminum sulfate and ferric chloride, and varied the factors pH, coagulant concentration, polymer concentration and rate of recirculation. At the end of the experiments were analyzed turbidity, suspended solids, color, COD and chlorophyll "a". These results were submitted to descriptive statistics to verify the efficiency of the process in general, and regression analysis to identify models that describe the process and demonstrate the factors that have greater influence on flotation. After step methodology, high values were found removal efficiency of suspended solids, reaching values greater than 90% in the best cases. It was concluded that flotation is more efficient in the facultative pond effluent using ferric chloride, and the variability of algae may negatively influence the process. Regression analyzes showed that pH is the most influential variable in the coagulation-flocculation-flotation, and its optimal value among the tested is 5.5 for both coagulants

Influencia de la deshidratación osmótica y de la adición de cloruro de calcio en la conservación de kivis minimamente procesados

Este trabajo tubo como objetivo estudiar el efecto combinado de la deshidratación osmótica y la influencia del cloruro de calcio en rodajas de kivi sometidos al proceso mínimo. Muestras con y sin deshidratación osmótica fueron almacenadas a 5 °C en embalajes PET. La adición de cloruro de calcio fue realizada durante la deshidratación osmótica. Se evaluaron la pérdida de peso, acidez, sólidos solubles, pH, humedad, coliformes, hongos y levaduras en las muestras hasta 15 días de almacenamiento. La deshidratación osmótica consistió en la inmersión de las rodajas de kivi en solución de sacarosa a 60% y en solución de sacarosa (60%) con adición de cloruro de calcio (0,1 M), ambos tratamientos se realizaron a temperatura ambiente (25 °C) por 24 horas y relación fruta:solución de 1:5. Los resultados mostraron que el pré-tratamiento osmótico con adición de cloruro de calcio aumentó la vida útil hasta 15 días, en cuanto las rodajas tratadas por osmodeshidratación sin adición de sal presentaron vida útil de 12 días. Sensorialmente, los consumidores prefirieron las rodajas de kivi procesadas con pré-tratamiento osmótico y adición de cloruro de calcio.

Susceptibility of Saccharomyces cerevisiae and lactic acid bacteria from the alcohol industry to several antimicrobial compounds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Qualidade fisiológica de sementes de genótipos de algodoeiro sob estresse salino

The germination of cotton seeds and the seedlings emergency are generally delayed and reduced by the salinity. Although the cotton is considered a tolerant culture, it can suffer substantial reductions in regarding its growth and production when exposed to salinity condition. The aims of this study went evaluate the effect of the saline stress in the germination phase to four cotton genotypes (BRS Rubi, BRS Safira, BRS 201 and CNPA 187 8H), using different osmotic potentials generated with increment of sodium chloride (NaCl). The saline stress was simulated using NaCl aqueous solutions in the potentials: 0.0 (Control); -0.2; -0.4; -0.6; -0.8 and -1.0 MPa. The treatments were monitored by means of tests for analysis of seeds, germination, first counting, speed germination index, length of shoot, radicle length, dry weigth of embrionic axis and shoot/radicle ratio. The tests for germination, first counting and index of germination speed were accomplished using 50 seeds for repetition and for the study of length of shoot, radicle length, dry weigth of embrionic axis and shoot/radicle ratio were used 20 seeds by repetition. For both tests four repetitions were accomplished by genotype for each one of the potentials. The seeds of each repetition were involved in papers Germitest humidified with NaCl solution corresponding to the potential. The repetitions of both tests were maintained in a germinator with saturated humidity. The analysis were initiate four days after the induction of the saline stress. The evaluations of the first three variables analyzed were accomplished daily; the seeds were remove and counted when its germinated. For the length tests just the repetitions corresponding to the potential of NaCl 0,0 MPa were analysis 4 days after the beginning of the induction of the saline stress. The analysis of the repetitions of the potentials -0,2 and -0,4 and of the potentials -0,6, -0,8 and -1,0 MPa they were accomplished with 12 and 20 days, respectively. For accomplishment of the analisis of this test the shoot of the 20 plantules of each repetition was separate from the radicle and both parts were measured. The statistical analyses were performed using the GENMOD and GLM procedures of the SAS. For the variable germination, the cultivates CNPA 187 8H and BRS Safira stood out for the potential -0.8 MPa, with averages of 89% and 81%, respectively. The test of speed germination index to cultivate BRS Safira presented the largest averages for the two higher saline potentials. It was observed that the increase of the saline potential reduces the germination percentage and speed germination index. For each day of evaluation it was verified that the increase of the saline potential causes a reduction of the length both of the shoot and of the radicle. The radicle tends to grow more than the shoot until the potential -0,4 MPa

Electrochemical evidence of sulfinic acid derivative as an intermediate in the reduction of aromatic sulfonyl chloride in an aprotic medium

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do comportamento de argila ativada na presença de água destilada, soluções salinas e inibidores de hidratação catiônicos

The clay swelling is today one of the major problems during the well drilling. Nearly 50% of clays that constitute shale expand easily in the presence of water molecules. During the drilling of a geological formation containing swelling clays, when is feasible the use of water base fluids, it is necessary to apply clay inhibitors. This avoids the incorporation of the cutting to the drilling fluid which is responsible for the wall swelling and crumbling. The aim of this work was to evaluate the synergistic behavior that occurs when swelling clay inhibitors are associated to NaCl and KCl salts. Three swelling clay inhibitors samples, INIB A, INIB B and INIB C, were analyzed. Each inhibitor was characterized by the amount of chlorides and active matter content. For the water-clay interaction evaluation in the presence of various fluids, it was used the Capillary Suction Timer (CST, Fann) and Linear Swell Meter (LSM 2000, Fann). For better interpretation of results, a Design of Experiments (DOE, Umetrics MODDE 7.0 TM) through Result Surface Methodology (RSM) was employed, taking into account the type, the swelling inhibitors concentration and the contact time with the clay. The results showed different efficiencies among the inhibitors employed, and the salt-inhibitors mixtures were more efficient than those products alone. However, for field operation, other parameters should be taking into account, as operational cost, environmental requests and time of application for each product