Impactos do estresse salino e da cobertura morta nas características químicas do solo e no desenvolvimento do amaranto

Availability of good quality water has been reduced vertiginously, over the last decade, in the world. In some regions, the water resources have high concentration of the dissolved salts, these characteristics of the water make it s use impossible. Water quality can be a limitation for irrigated agriculture, principally in regions of arid or semiarid climate where the water resources are generally saline and are exposed at high evaporation ratio. For that reason, precipitation of the salts occurs near the soil surface and those salts themselves cumulate in the vegetal tissue, reducing the soil fertility and crop production. The adoption of tolerant crop to the water salinity and soil salinity, adaptable to the climatic conditions is other emergent necessity. This work had the goal of studying the effects of four salinity levels of the irrigation water salinity and use of mulch, dried leaves of Forest mangrove (Acacia mangiumWilld), in cultivated soil with amaranth (Amaranthus cruentus, BRS Alegria variety), in greenhouse. It was utilized the transplant of plants to PVC columns, containing 30 kg of silty loam soil, 10 days after emerging, with space of 50 x 50 cm between lines. Treatments were composed by combination of four levels of salinity (0.147; 1.500; 3.000 e 4.500 dS m-1), obtained by addition NaCl (commercial) to irrigation water and soil with and without protection, by mulch. A factorial system 4 x 2 was used with four repetitions, totalizing 32 parcels. The concentrations of nutrients in soil solution have been evaluated, in the dry matter of the vegetal tissue (roots, stem, leaves and raceme residue), at the end of the vegetative cycle. The use of soil protection reduced time for the beginning inflorescence of plants, at the same time, the increase of the salinity delayed this phase of amaranth development. The use of the mulch effectively increased the height, stem diameter, area of the larger leaf, humidity and dry matter content and amaranth grain production. The vegetal species showed salinity tolerance to experimented levels. The adopted treatments did not affect the pH values, exchangeable cation contents, electrical conductivity of soil solution (EC1:5) and saturated extract (ECSE), and Ca+2, Mg+, Fe+2 and Mn+2 contents, in the soil solution. The increase of the salinity concentration in the irrigation water inhibited the mineralization process of the organic matter (OM) and, consequently, the efficiency in the it´s utilization by plants, at the same time, produced increase in the values of the exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) and potassium adsorption ratio (PAR), in the soil solution. Therefore, the use of the mulch did not affect the first three parameters. The protein and nutrient contents: K+, Ca+2, P, Mg+2 e Cu+2, in amaranth grains, were improved by tillage condition. The raceme residues showed chemical/nutritional composition that makes advantageous its application in animal ration. In this context, it follows that amaranth tolerate the saline stress, of the irrigation water, until 4.500 dS m-1, temperature and relative humidity of the air predominant in the experimental environment

Investigação dos processos hidrossedimentológicos em parcela experimental no semi-árido potiguar

In northeastern semiarid, seasonality on precipitation temporal distribution, high intensity storm events and inadequate management of native vegetation can promote soil erosion. Vegetation removal causes soil surface exposure, reduces soil water storage capacity and can be the source degradation processes. In this context, this approach aims to analyze water and soil erosion processes on a 250 m2 undisturbed experimental plot with native vegetation, slope 2.5% by using 2006 and 2007 monitoring data. The site was instrumented to monitor rainfall, overland flow runoff and erosion by using a 5 m³ tank downstream the plot. Soil erosion monitoring was made by transported sediment and organic matter collection after each event. Field infiltration experiments were made at 16 points randomly distributed within the plot area by using a constant head infiltrometer during drought and rainy seasons, respectively. Infiltration data revealed high spatial and temporal variability. It was observed that during the beginning of the rainy period, 77% of the events showed runoff coefficient less than 0.05. As the rainy season began, soil water increase produced annual species germination. High intensity storms resulted in runoff coefficients varying between 0.33 and 0.42. Once the annual species was established, it was observed that approximately 39% of the events produced no runoff, which reflects an increase on soil water retention capacity caused by the vegetation. A gradual runoff reduction during the rainy season emphasizes the effect of vegetative density increase. Soil erosion observed data allowed to fit an empirical relationship involving soil loss and precipitation height, which was used to analyze the plot installation impact on soil erosion. Observed soil loss in 2006 and 2007 was 230 Kg/ha and 54 Kg/ha, respectively

Caracterização e aplicação de vermicultura natural e quimicamente modificada na adsorção de azul de metileno

Chemical modification of clays has been extremely studied in the search for improvements of their properties for use in various areas, such as in combating pollution by industrial effluents and dyes. In this work, the vermiculite was chemically modified in two ways, characterized and evaluated the adsorption of methylene blue dye. First was changed with the addition of a surfactant (hexadecyltrimethylammonium bromide, BHTA) making it an organophilic clay and then by adding an acid (HCl) by acid activation. Some analyzes were performed as X-ray fluorescence (FRX), X-ray diffraction (DRX), adsorption isotherms of methylene blue dye, infrared (FTIR) , scanning electron microscopy (SEM), thermal gravimetric analysis and spectroscopy energy dispersive (EDS). Analysis by FRX of natural vermiculite indicates that addition of silicon and aluminum, clay presents in its structure the magnesium, calcium and potassium with 16 % organic matter cations. The DRX analyzes indicated that the organic vermiculite was an insertion of the surfactant in the space between the lamellae, vermiculite and acid partial destruction of the structure with loss of crystallinity. The adsorption isotherms of methylene blue showed that there was a significant improvement in the removal of dye to the vermiculite with the addition of cationic surfactant hexadecyltrimethylammonium bromide and treatment with acid using HCl 2 mol/L. In acid vermiculites subsequently treated with surfactant, the adsorption capacity increased with respect to natural vermiculite, however was much lower compared vermiculite modified with acid and surfactant separately. Only the acidic vermiculite treated with surfactant adjusted to the Langmuir model. As in the infrared spectrometry proved the characteristics of natural vermiculite. In the organic vermiculite was observed the appearance of characteristic bands of CH3, CH2, and (CH3)4N. Already on acid vermiculite, it was realized a partial destruction with decreasing intensity of the characteristic band of vermiculite that is between 1074 and 952 cm-1. In the SEM analysis, it was observed that there was partial destruction to the acid treatment and a cluster is noted between the blades caused by the presence of the surfactant. The TG shows that the higher mass loss occurs at the beginning of the heating caused by the elimination of water absorbed on the surface between layers. In the organic vermiculite also observed a loss of mass between 150 and 300 °C caused decomposition of the alkylammonium molecules (surfactants)

Caracterização morfológica-sedimentar do vale inciso Apodi-Mossoró e plataforma continental adjacente - Bacia Potiguar Offshore

Systems of incised valleys have been studied in different continental shelves, including the Brazilian continental margin. The interest to characterize this feature is given by the information that it can provide variations on sea level, as well as the ability to host economically significant quantities of hydrocarbons in reservoirs located in deposits filling of the incised valleys. This thesis has the overall objective to characterize the morphology and sedimentary cover of the incised valley Apodi-Mossoró, located in the Northern Continental shelf of Rio Grande do Norte state, adjacent to Areia Branca city. The methodology included the integration of satellite imagery, bathymetric data, sedimentological data, shallow seismic, and the identification of foraminifera. The results indicate that the ApodiMossró incised valley is currently formed by two channels, shallow channel and deep channel, which have distinct morphological and sedimentological characteristics. The deep channel has connection with one of the heads of the Apodi Canyon, located in the slope area. The acquisition, processing and interpretation of shallow seismic data allowed the recognition of the depositional surface, erosional surface, discordance, and sismofaceis. The erosional surface mapped from shallow seismic sections is possibly a indicative of an ancient surface of valley incision, where it would probably be associated with the limit Pleistocene/Holocene. Different sismofaceis were identified and reflect the rise in sea level with standards sometimes agradacional, sometimes progradational. The thickness of sediments on this surface was estimated at a maximum of 22m thick in the central portion of the incised valley. Statistically, there are differences between the adjacent continental shelf and channels, and between these channels, for the content of calcium carbonate, organic matter, sand and mud perceptual, except for the gravel grain size. The analysis of living and dead foraminifera showed the presence of fifty species distributed in regards to morphology, depth and type of sediment. Four type of seismic echocharacteres were identified and mapped, as well as their bedforms, indicating different sedimentary processes along the incised valley. The integration of results suggests an activation of the Apodi-Mossoró incised valley in the Late Pleistocene.

Análise da biorremediação de compostos monoaromáticos em água através da pseudomonas aeruginosa

The monoaromatic compounds are toxic substances present in petroleum derivades and used broadly in the chemical and petrochemical industries. Those compounds are continuously released into the environment, contaminating the soil and water sources, leading to the possible unfeasibility of those hydrous resources due to their highly carcinogenic and mutagenic potentiality, since even in low concentrations, the BTEX may cause serious health issues. Therefore, it is extremely important to develop and search for new methodologies that assist and enable the treatment of BTEX-contaminated matrix. The bioremediation consists on the utilization of microbial groups capable of degrading hydrocarbons, promoting mineralization, or in other words, the permanent destruction of residues, eliminating the risks of future contaminations. This work investigated the biodegradation kinetics of water-soluble monoaromatic compounds (benzene, toluene and ethylbenzene), based on the evaluation of its consummation by the Pseudomonas aeruginosa bacteria, for concentrations varying from 40 to 200 mg/L. To do so, the performances of Monod kinetic model for microbial growth were evaluated and the material balance equations for a batch operation were discretized and numerically solved by the fourth order Runge-Kutta method. The kinetic parameters obtained using the method of least squares as statistical criteria were coherent when compared to those obtained from the literature. They also showed that, the microorganism has greater affinity for ethylbenzene. That way, it was possible to observe that Monod model can predict the experimental data for the individual biodegradation of the BTEX substrates and it can be applied to the optimization of the biodegradation processes of toxic compounds for different types of bioreactors and for different operational conditions.

Análise da biorremediação de compostos monoaromáticos em água através da pseudomonas aeruginosa

The monoaromatic compounds are toxic substances present in petroleum derivades and used broadly in the chemical and petrochemical industries. Those compounds are continuously released into the environment, contaminating the soil and water sources, leading to the possible unfeasibility of those hydrous resources due to their highly carcinogenic and mutagenic potentiality, since even in low concentrations, the BTEX may cause serious health issues. Therefore, it is extremely important to develop and search for new methodologies that assist and enable the treatment of BTEX-contaminated matrix. The bioremediation consists on the utilization of microbial groups capable of degrading hydrocarbons, promoting mineralization, or in other words, the permanent destruction of residues, eliminating the risks of future contaminations. This work investigated the biodegradation kinetics of water-soluble monoaromatic compounds (benzene, toluene and ethylbenzene), based on the evaluation of its consummation by the Pseudomonas aeruginosa bacteria, for concentrations varying from 40 to 200 mg/L. To do so, the performances of Monod kinetic model for microbial growth were evaluated and the material balance equations for a batch operation were discretized and numerically solved by the fourth order Runge-Kutta method. The kinetic parameters obtained using the method of least squares as statistical criteria were coherent when compared to those obtained from the literature. They also showed that, the microorganism has greater affinity for ethylbenzene. That way, it was possible to observe that Monod model can predict the experimental data for the individual biodegradation of the BTEX substrates and it can be applied to the optimization of the biodegradation processes of toxic compounds for different types of bioreactors and for different operational conditions.

Remoção de fenol de efluentes aquosos utilizando floculação iônica

Oil exploration is one of the most important industrial activities of modern society. Despite its derivatives present numerous applications in industrial processes, there are many undesirable by-products during this process, one of them is water separated from oil, called water production, it is constituted by pollutants difficult to degrade. In addition, the high volume of generated water makes its treatment a major problem for oil industries. Among the major contaminants of such effluents are phenol and its derivatives, substances of difficult natural degradation, which due their toxicity must be removed by a treatment process before its final disposal. In order to facilitate the removal of phenol in wastedwater from oil industry, it was developed an extraction system by ionic flocculation with surfactant. The ionic flocculation relies on the reaction of carboxylate surfactant and calcium íons, yielding in an insoluble surfactant that under stirring, aggregates forming floc capable of attracting the organic matter by adsorption. In this work was used base soap as ionic surfactant in the flocculation process and evaluated phenol removal efficiency in relation to the following parameters: surfactant concentration, phenol, calcium and electrolytes, stirring speed, contact time, temperature and pH. The flocculation of the surfactant occurred in the effluent (initial phenol concentration = 100 ppm) reaching 65% of phenol removal to concentrations of 1300 ppm and calcium of 1000 ppm, respectively, at T = 35 °C, pH = 9.7, stirring rate = 100 rpm and contact time of 5 minutes. The permanence of the flocs in an aqueous medium promotes desorption of the phenol from the flake surface to the solution, reaching 90% of desorption at a time of 150 minutes, and the study of desorption kinetics showed that Lagergren model of pseudo-first order was adequate to describe the phenol desorption. These results shows that the process may configure a new alternative of treatment in regard the removal of phenol of aqueous effluent of oil industry.

Remoção de fenol de efluentes aquosos utilizando floculação iônica

Oil exploration is one of the most important industrial activities of modern society. Despite its derivatives present numerous applications in industrial processes, there are many undesirable by-products during this process, one of them is water separated from oil, called water production, it is constituted by pollutants difficult to degrade. In addition, the high volume of generated water makes its treatment a major problem for oil industries. Among the major contaminants of such effluents are phenol and its derivatives, substances of difficult natural degradation, which due their toxicity must be removed by a treatment process before its final disposal. In order to facilitate the removal of phenol in wastedwater from oil industry, it was developed an extraction system by ionic flocculation with surfactant. The ionic flocculation relies on the reaction of carboxylate surfactant and calcium íons, yielding in an insoluble surfactant that under stirring, aggregates forming floc capable of attracting the organic matter by adsorption. In this work was used base soap as ionic surfactant in the flocculation process and evaluated phenol removal efficiency in relation to the following parameters: surfactant concentration, phenol, calcium and electrolytes, stirring speed, contact time, temperature and pH. The flocculation of the surfactant occurred in the effluent (initial phenol concentration = 100 ppm) reaching 65% of phenol removal to concentrations of 1300 ppm and calcium of 1000 ppm, respectively, at T = 35 °C, pH = 9.7, stirring rate = 100 rpm and contact time of 5 minutes. The permanence of the flocs in an aqueous medium promotes desorption of the phenol from the flake surface to the solution, reaching 90% of desorption at a time of 150 minutes, and the study of desorption kinetics showed that Lagergren model of pseudo-first order was adequate to describe the phenol desorption. These results shows that the process may configure a new alternative of treatment in regard the removal of phenol of aqueous effluent of oil industry.

Influência dos fatores abióticos sobre a variação espaço-temporal de paralonchurus brasiliensis (Steindachner, 1875) (pisces, sciaenidae) componente da fauna acompanhante da pesca de camarões no litoral Norte de São Paulo

Knowledge of the environmental factors influence on the spatial-temporal variation of fishes is important to fisheries management and conservation. Thus, the aim of this work was to analyze the influence of the abiotical factors on the spatial-temporal distribution of Paralonchurus brasiliensis (Pisces, Sciaenidae) caught by-catch with the shrimp fishing of Ubatuba and Caraguatatuba regions, north coast of São Paulo State. The fishes were captured every month from January to December 2002. Samples were collected by otter trawl at 5, 10, 15, 20, 25, 30 and 35m depths. The temperatures (surface and bottom), salinities (surface and bottom), sediment features and organic matters were verified for each depth. During all period of the study 12.642 specimens of P. brasiliensis were captured at Ubatuba and 17.166 at Caraguatatuba, which totalized the biomass of 267 for the first and 339kg for the other region. The females outnumbered males in fish population. The greatest values of biomass and number of individuals were registered at the summer and autumn seasons, while the lowest values were observed at the winter and spring seasons. The greatest abundances were found from 15 to 25m depth. In this study, it was verified that P. brasiliensis is a coastal waters associate species. The spatialtemporal distribution of P. brasiliensis is affected by intrusion of SACW and depth for the coastal region and by depth and sediment in sheltered areas such as Caraguatatuba

Utilização da macroalga Ulva lactuca linnaeus na redução de nutrientes (NH4+,NO3- e PO4-2) provenientes da carcinicultura

Dentre as macroalgas capazes de absorver altas concentrações de N e P dissolvidos na água, destaca-se a Chlorophyta Ulva lactuca, bastante adaptável e resistente às adversidades ambientais, como grandes variações de temperatura, salinidade, matéria orgânica e metais pesados. Trata-se também de uma espécie bastante comum nas áreas intertidais do litoral norte-riograndense. Devido a suas características ecológicas, fisiológicas e nutricionais, foi avaliado nesse estudo, o seu potencial como biofiltro na redução de NH4+, NO3- e PO4-2, tanto em condições controladas como também em um viveiro de camarão. No experimento laboratorial, foram utilizados quatro aquários de vidro de 30 x 20 x 20cm com 10L de água, sendo três aquários experimentais contendo 20g de U. lactuca e um controle. O acréscimo de biomassa foi de 2,92g (22,92 ± 6,29g; p < 0,05) em relação ao inóculo inicial de 20g, sob temperatura (28,50 ± 0,58ºC), salinidade (35,00 ± 0,00 ), pH (8,26 ± 0,02) e luz constante (250 μmol.m2s-1). O crescimento positivo (1,78 ± 4,38%dia-1; p < 0,05), juntamente com a alta eficiência de absorção de amônio (83%; p < 0,001), nitrato (83%; p < 0,001) e ortofosfato (53%; p < 0,001), demonstrou que, nessas condições, a Ulva lactuca absorveu os nutrientes e aumentou sua biomassa. Já no experimento de campo, realizado na fazenda TECNARÃO, situada no município de Arez/RN (06° 11 40 Latitude Sul, e 35º 09 37 Longitude Oeste), foram utilizadas três gaiolas de PVC, posicionadas a 12cm da superfície da água, cada uma com dimensões de aproximadamente 59 x 59 x 15cm, onde foram colocadas 200g de U. lactuca. O ganho de biomassa de 3g (203,00 ± 41,02g; p < 0,001) foi muito semelhante às condições controladas, demonstrando a adaptabilidade da espécie em condições ambientais variáveis, onde, apesar da temperatura pouco variável (27,45 ± 0,64ºC), houve progressiva diminuição de salinidade (25 - 15 ), devido ao período de fortes chuvas (34,70 ± 23,78mm). Somado a isso, foram observados vários fatores biológicos interferindo no viveiro, como a presença de epífitas, organismos endofíticos, fouling e a herbivoria por parte dos próprios camarões. Houve aumento nas concentrações de NH4+ (4,36 ± 1,69 μmol.L-1), NO3- (0,17 ± 0,25μmol.L-1) e PO4-2 (0,41 ± 0,13μmol.L-1), coincidindo com o crescimento da espécie até a terceira semana. Todos os parâmetros ambientais analisados, assim como a biomassa e a Taxa de Crescimento Relativo (TCR), obtidos no campo, apresentaram variações altamente significativas (p < 0,001). As correlações observadas entre biomasa e NH4+ (r = 0,82; p < 0,001) e entre biomassa e PO4-2 (r = 0,87; p < 0,001), indicam que esta espécie é capaz de ter um crescimento satisfatório nas condições eutróficas de um viveiro de camarão, sendo possível seu uso como biofiltro.

Obtenção e caracterização de nanopartículas de argilominerais

Natural nanoclays are of great interest particularly for the production of polymer-based nanocomposites. In this work, kaolinite clays from two natural deposits in the State of the Rio Grande do Norte and Paraiba were purified with thermal treatment and chemical treatments, and characterized. Front to the gotten data, had been proposals methodologies for elimination or reduction of coarse particle texts, oxide of iron and organic substance. These methodologies had consisted of the combination of operations with thermal treatments, carried through in electric oven, and acid chemical attacks with and hydrogen peroxide. The Analyzers Thermogravimetric was used to examine the thermal stability of the nanoclays. The analysis indicated weight losses at temperatures under 110 ºC and over the temperature range of 350 to 550 ºC. Based on the thermal analysis data, the samples were submitted to a thermal treatment at 500 °C, for 8 h, to remove organic components. The X-ray diffraction patterns indicated that thermal treatment under 500 °C affect the basic structure of kaolinite. The BET surface area measurements ranged from 32 to 38 m2/g for clay samples with thermal treatment and from 36 to 53 m2/g for chemically treated samples. Thus, although the thermal treatment increased the surface area, through the removal of organic components, the effect was not significant and chemical treatment is more efficient, not affect the basic structure of kaolinite, to improve particle dispersion. SEM analysis confirms that the clay is agglomerated forming micron-size particles

Térmitas como bioindicadores de qualidade de habitat na caatinga, Brasil: há uma sintonia entre as variáveis estruturais dos habitats e as taxocenoses amostradas?

The composition of termite assemblages was analyzed at three Caatinga sites of the Seridó Ecological Station, located in the municipality of Serra Negra do Norte, in the state of Rio Grande do Norte, Brazil. These sites have been subjected to selective logging, and cleared for pasture and farming. A standardized sampling protocol for termite assemblages (30h/person/site) was conducted between September 2007 and February 2009. At each site we measured environmental variables, such as soil granulometry, pH and organic matter, necromass stock, vegetation height, tree density, stem diameter at ankle height (DAH) and the largest and the smallest crown width. Ten species of termites, belonging to eight genera and three families, were found at the three experimental sites. Four feeding-groups were sampled: wood-feeders, soil-feeders, wood-soil interface feeders and leaf-feeders. The wood-feeders were dominant in number of species and number of encounters at all sites. In general, the sites were not significantly different in relation to the environmental variables measured. The same pattern was observed for termite assemblages, where no significant differences in species richness, relative abundance and taxonomic and functional composition were observed between the three sites. The agreement between the composition of assemblages and environmental variables reinforces the potential of termites as biological indicators of habitat quality

Síntese, caracterização e cinética da decomposição térmica dos materiais cerâmicos PrMO3 (M = Ni ou Co)

In this work have been studied the preparation, characterization and kinetic study of decomposition of the polymerizing agent used in the synthesis under non-isothermal condition ceramics PrMO3 of general formula (M = Co and Ni). These materials were obtained starting from the respective metal nitrates, as a cations source, and making use of gelatin as polymerizing agent. The powders were calcined at temperatures of 500°C, 700°C and 900°C and characterized by X-ray Diffraction (XRD), Thermogravimetric Analysis (TG / DTG/ DTA), Infrared Spectroscopy (FTIR), Temperature Programmed Reduction (TPR) and Scanning Electron Microscopy (SEM). The perovskite phase was detected in all the X-rays patterns. In the infrared spectroscopy observed the oxide formation as the calcination temperature increases with the appearance of the band metal - oxygen. The images of SEM revealed uniform distribution for the PrCoO3 and particles agglomerated as consequence of particle size for PrNiO3. From the data of thermal analysis, the kinetics of decomposition of organic matter was employed using the kinetics methods called Model Free Kinetics and Flynn and Wall, in the heating ratios 10, 20 and 30° C.min-1 between room temperature and 700°C. Finally, been obtained the values of activation energy for the region of greatest decomposition of organic matter in samples that were determined by the degree of conversion (α)

Síntese, estudo cinético e análise microestrutural do sistema cério-níquel obtido pelo método pechini

The cerium oxide has a high potential for use in removing pollutants after combustion, removal of organic matter in waste water and the fuel-cell technology. The nickel oxide is an attractive material due to its excellent chemical stability and their optical properties, electrical and magnetic. In this work, CeO2-NiO- systems on molars reasons 1:1(I), 1:2(II) e 1:3(III) metal-citric acid were synthesized using the Pechini method. We used techniques of TG / DTG and ATD to monitor the degradation process of organic matter to the formation of the oxide. By thermogravimetric analysis and applying the dynamic method proposed by Coats-Redfern, it was possible to study the reactions of thermal decomposition in order to propose the possible mechanism by which the reaction takes place, as well as the determination of kinetic parameters as activation energy, Ea, pre-exponential factor and parameters of activation. It was observed that both variables exert a significant influence on the formation of complex polymeric precursor. The model that best fitted the experimental data in the dynamic mode was R3, which consists of nuclear growth, which formed the nuclei grow to a continuous reaction interface, it proposes a spherical symmetry (order 2 / 3). The values of enthalpy of activation of the system showed that the reaction in the state of transition is exothermic. The variables of composition, together with the variable temperature of calcination were studied by different techniques such as XRD, IV and SEM. Also a study was conducted microstructure by the Rietveld method, the calculation routine was developed to run the package program FullProf Suite, and analyzed by pseudo-Voigt function. It was found that the molar ratio of variable metal-citric acid in the system CeO2-NiO (I), (II), (III) has strong influence on the microstructural properties, size of crystallites and microstrain network, and can be used to control these properties

Diagnóstico da possível influência da atividade petrolífera em sedimentos de fundo da Bacia Piranhas-Açu, região Baixo Açu/RN

It is located in an area of increasing oil exploration, the region of the Lower Açu is at the mercy of a possible pollution generated by this economic activity, which includes various chemical substances harmful to health, such as metals. This thesis aims to, diagnose the areas of River Piranhas-Açu, a region of the Lower Açu, which are polluted by traces factors and more. In this study, it was determined the concentration of the chemica elements Al, CD, Cr, Cu, Fe, Mn, Ni, P, Pb, V and Zn, through the technique of ICP-OES analysis and the size of sediments and their contents organic matter. Were mapped by GPS, 12 points from collections. The interpretations of the results, together associating that allowed pollution to a possible contamination by oil activity. The results showed tha some regions have low concentrations of cadmium, lead, copper, manganese and zinc unable to promote damage to human health. However, there are places where the concentrations of certain metals chromium, iron and zinc are moderately polluted compared to the results with the reference values of literature and others that are highly polluted by iron. However, due to a greater number of wells in production in those locations, those higher concentrations, it can be suggested a possible influence of oi production in some areas with concentrations of chromium and lead are higher than the rest of the points of monitoring. Moreover, it is observed that the highest levels of metals found in sediment of finer texture and more organic matter content