18 resultados para Aliphatic hydrocarbons. Bottom sediments. Potengi River estuary, Natal - RN
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The Potengi river estuary is located in the region of Natal (RN, Brazil), comprising a population of approximately 1,000,000 inhabitants. Besides the dominant urban presence, the estuary has fragments of mangrove forest. The objective of this study is to determine the aliphatic hydrocarbons found in the bottom sediments of this estuary, identifying their levels, distribution and their possible origins through the diagnostic rates, indexes and results comparisons with the local anthropic and natural characteristics. The samples were obtained according to a plan that allowed sampling of the estuary up to 12 km upstream from it as mounth. 36 stations were selected, grouped into 12 cross sections through the course of the river and spaced on average by 1 km. Each section consisted of three stations: the right margin, the deepest point and the left margin. The hydrocarbon n-alkanes from C10 to C36, the isoprenoids pristane and phytane, the unresolved complex mixture (UCM) and the total resolved hydrocarbons were analyzed by gas chromatography. N-alkanes, pristane, phytane and UCM were detected only at some stations. In the other, the concentration was below the detection limit defined by the analytical method (0.1 mg / kg), preventing them from being analyzed to determine the origin of the material found. By using different parameters, the results show that the estuary receives both the input of petrogenic hydrocarbons, but also of biogenic hydrocarbons, featuring a mixture of sources and relatively impacted portions. Based on the characteristics and activities found in the region, it is possible to affirm that petrogenic sources related to oil products enter the estuary via urban runoff or boats traffic, boat washing and fueling. Turning to the biogenic source, the predominant origin was terrestrial, characterized by vascular plants, indicating contribution of mangrove vegetation. It was evident the presence of, at specific points in the estuary, hydrocarbon pollution, and, therefore is recommended the adoption of actions aimed at interrupting or, at least, mitigating the sources potentially capable of damp petrogenic hydrocarbons in the estuary studied.
Resumo:
The Potengi river estuary is located in the region of Natal (RN, Brazil), comprising a population of approximately 1,000,000 inhabitants. Besides the dominant urban presence, the estuary has fragments of mangrove forest. The objective of this study is to determine the aliphatic hydrocarbons found in the bottom sediments of this estuary, identifying their levels, distribution and their possible origins through the diagnostic rates, indexes and results comparisons with the local anthropic and natural characteristics. The samples were obtained according to a plan that allowed sampling of the estuary up to 12 km upstream from it as mounth. 36 stations were selected, grouped into 12 cross sections through the course of the river and spaced on average by 1 km. Each section consisted of three stations: the right margin, the deepest point and the left margin. The hydrocarbon n-alkanes from C10 to C36, the isoprenoids pristane and phytane, the unresolved complex mixture (UCM) and the total resolved hydrocarbons were analyzed by gas chromatography. N-alkanes, pristane, phytane and UCM were detected only at some stations. In the other, the concentration was below the detection limit defined by the analytical method (0.1 mg / kg), preventing them from being analyzed to determine the origin of the material found. By using different parameters, the results show that the estuary receives both the input of petrogenic hydrocarbons, but also of biogenic hydrocarbons, featuring a mixture of sources and relatively impacted portions. Based on the characteristics and activities found in the region, it is possible to affirm that petrogenic sources related to oil products enter the estuary via urban runoff or boats traffic, boat washing and fueling. Turning to the biogenic source, the predominant origin was terrestrial, characterized by vascular plants, indicating contribution of mangrove vegetation. It was evident the presence of, at specific points in the estuary, hydrocarbon pollution, and, therefore is recommended the adoption of actions aimed at interrupting or, at least, mitigating the sources potentially capable of damp petrogenic hydrocarbons in the estuary studied.
Resumo:
Environmental issues are becoming increasingly habitual to the media, particularly when calamities are involved. A feature of environmental disasters is that they disclose both environmental crises and the media limitation in reporting them. The research tried to contribute to the subject through the study of press media coverage of a large fish kill along an estuary in the State of Rio Grande do Norte, Brazil, in 2007. Thematic content analysis of newspaper reports identified the predominance of a superficial and denunciative coverage, lacking an educational perspective, and with little contribution to formation of a critical sense in readers. It also has identified the precarious treatment of those scientific concepts that could substantiate the actual causes of mortality of tons of aquatic fauna
Resumo:
Estuaries are environments prone to the input of chemical pollutants of various kinds and origins, including polycyclic aromatic hydrocarbons (PAHs). Anthropogenic PAHs may have two possible sources: pyrolytic (with four or more aromatic rings and low degree of alkylation) and petrogenic (with two and three aromatic rings and high degree of alkylation). This study aimed to evaluate the levels, distribution and possible sources of polycyclic aromatic hydrocarbons in the estuary of the Potengi river, Natal, Brazil. Samples of bottom sediments were collected in the final 12 km of the estuary until its mouth to the sea, where the urbanization of the Great Natal is more concentrated. Sampling was performed on 12 cross sections, with three stations each, totaling 36 samples, identified as T1 to T36. The non alkylated and alkylated PAHs were analyzed by gas chromatography coupled to mass spectrometry (GC / MS). PAHs were detected in all 36 stations with total concentration on each varying 174-109407 ng g-1. These values are comparable to those of several estuarine regions worldwide with high anthropogenic influence, suggesting the record of diffuse contamination installed in the estuary. PAHs profiles were similar for most stations. In 32 of the 36 stations, low molecular weight PAHs (with 2 and 3 ring: naphthalene, phenanthrene and their alkylated homologues) prevailed, which ranged from 54% to 100% of the total PAH, indicating that leaks, spills and combustion fuels are the dominant source of PAH pollution in the estuary. The level of contamination by PAHs in most stations suggests that there is potential risk of occasional adverse biological effects, but in some stations adverse impacts on the biota may occur frequently. The diagnostic ratios could differentiate sources of PAHs in sediments of the estuary, which were divided into three groups: petrogenic, pyrolytic and mixing of sources. The urban concentration of the Great Natal and the various industrial activities associated with it can be blamed as potential sources of PAHs in bottom sediments of the estuary studied. The data presented highlight the need to control the causes of existing pollution in the estuary
Resumo:
Estuaries are environments prone to the input of chemical pollutants of various kinds and origins, including polycyclic aromatic hydrocarbons (PAHs). Anthropogenic PAHs may have two possible sources: pyrolytic (with four or more aromatic rings and low degree of alkylation) and petrogenic (with two and three aromatic rings and high degree of alkylation). This study aimed to evaluate the levels, distribution and possible sources of polycyclic aromatic hydrocarbons in the estuary of the Potengi river, Natal, Brazil. Samples of bottom sediments were collected in the final 12 km of the estuary until its mouth to the sea, where the urbanization of the Great Natal is more concentrated. Sampling was performed on 12 cross sections, with three stations each, totaling 36 samples, identified as T1 to T36. The non alkylated and alkylated PAHs were analyzed by gas chromatography coupled to mass spectrometry (GC / MS). PAHs were detected in all 36 stations with total concentration on each varying 174-109407 ng g-1. These values are comparable to those of several estuarine regions worldwide with high anthropogenic influence, suggesting the record of diffuse contamination installed in the estuary. PAHs profiles were similar for most stations. In 32 of the 36 stations, low molecular weight PAHs (with 2 and 3 ring: naphthalene, phenanthrene and their alkylated homologues) prevailed, which ranged from 54% to 100% of the total PAH, indicating that leaks, spills and combustion fuels are the dominant source of PAH pollution in the estuary. The level of contamination by PAHs in most stations suggests that there is potential risk of occasional adverse biological effects, but in some stations adverse impacts on the biota may occur frequently. The diagnostic ratios could differentiate sources of PAHs in sediments of the estuary, which were divided into three groups: petrogenic, pyrolytic and mixing of sources. The urban concentration of the Great Natal and the various industrial activities associated with it can be blamed as potential sources of PAHs in bottom sediments of the estuary studied. The data presented highlight the need to control the causes of existing pollution in the estuary
Resumo:
This study presents the Environmental Sensibility Mapping to oil spillings on the Potengi estuary - RN and neighboring coastline through remote sensing data, collecting, treatment and integration of the geomorphologic, oceanographic (temperature, salinity, density, direction and intensity), meteorological (wind speed and direction) and high resolution seismic (bathymetry and sonography) data. The Potengi river estuary is located on the eastern coastline of the Rio Grande do Norte State, being inserted in the geological context for the coastal Pernambuco-Paraíba basin and spreading over 18 km; it shelters the Natal harbor zone and an oil terminal, centralizing, therefore, important oil transport operations that can cause accidental spillings. Under the oceanographic point of view, the Potengi estuary is characterized by the absence of any expressive thermic stratification, being classified as partially mixed, B type according to Pritchard (1955), and 2 type in conformity to the stratification-circulation diagram by Hansen & Rattray (1966). Two main wind systems are responsable for the formation of wave sets that occur in the area. The dynamic tide presents, in the Natal Harbor, mean amplitude in spring and quadrature tides, with around 2.8 and 2m, respectively. The mechanism of saline tide mixing was defined through the salinity which is the main parameter for the identification of this mechanism. Important variations of the salinity mean values (36.32 psu), temperature (28.11ºC) and density (22.96 kg/m3) in the estuarine waters presented features belonging to low latitude regions. The water temperature follows the air temperature variations, in the region, with expressive daily amplitudes. In this study, the identification of the estuarine bed morphology through bathymetric and sonographic analysis, had the purpose to evaluate the influence of the superficial and bottom currents for the bottom shaping. In this way, the use of the side scan sonar showed, to be very useful in the identification of the bottom morphology and its relationship with the predominant action of the tidal currents in the Potengi estuary. Besides, it showed how the sonograms can be a support to the comparison of the several patterns derived from the local hydrodynamic variations. The holocene sediments, which fill the estuarine channel, are predominantly sandy, varying from selected, sometimes silty. The sedimentation is controlled by the environmental hydrodynamic conditions, being recognized two important textural facies: Muddy Facies and Sandy Facies. The distribution of these textural facies apparently oscillates owing to the tidal cycle and flow intensity. Each one of the above mentioned data was integrated in a Geographic Information System (GIS), from which was produced the Environmental Sensibility Map to oil spillings with Coastal Sensibility Index (CSI) to the Potengi estuary. The integrated analysis of these data is essential to oil spilling contingency plans, in order to reduce the spilling environmental consequences and to make efficient the endeavours of contention and cleaning up/removal on the Natal Harbor. This study has the aim to collaborate for the increase of informations about the estuarine environment and contribute to a better management of the question: environment/polluting loads
Resumo:
Untreated effluents that reach surface water affect the aquatic life and humans. This study aimed to evaluate the wastewater s toxicity (municipal, industrial and shrimp pond effluents) released in the Estuarine Complex of Jundiaí- Potengi, Natal/RN, through chronic quantitative e qualitative toxicity tests using the test organism Mysidopsis Juniae, CRUSTACEA, MYSIDACEA (Silva, 1979). For this, a new methodology for viewing chronic effects on organisms of M. juniae was used (only renewal), based on another existing methodology to another testorganism very similar to M. Juniae, the M. Bahia (daily renewal).Toxicity tests 7 days duration were used for detecting effects on the survival and fecundity in M. juniae. Lethal Concentration 50% (LC50%) was determined by the Trimmed Spearman-Karber; Inhibition Concentration 50% (IC50%) in fecundity was determined by Linear Interpolation. ANOVA (One Way) tests (p = 0.05) were used to determinate the No Observed Effect Concentration (NOEC) and Low Observed Effect Concentration (LOEC). Effluents flows were measured and the toxic load of the effluents was estimated. Multivariate analysis - Principal Component Analysis (PCA) and Correspondence Analysis (CA) - identified the physic-chemical parameters better explain the patterns of toxicity found in survival and fecundity of M. juniae. We verified the feasibility of applying the only renewal system in chronic tests with M. Juniae. Most efluentes proved toxic on the survival and fecundity of M. Juniae, except for some shrimp pond effluents. The most toxic effluent was ETE Lagoa Aerada (LC50, 6.24%; IC50, 4.82%), ETE Quintas (LC50, 5.85%), Giselda Trigueiro Hospital (LC50, 2.05%), CLAN (LC50, 2.14%) and COTEMINAS (LC50, IC50 and 38.51%, 6.94%). The greatest toxic load was originated from ETE inefficient high flow effluents, textile effluents and CLAN. The organic load was related to the toxic effects of wastewater and hospital effluents in survival of M. Juniae, as well as heavy metals, total residual chlorine and phenols. In industrial effluents was found relationship between toxicity and organic load, phenols, oils and greases and benzene. The effects on fertility were related, in turn, with chlorine and heavy metals. Toxicity tests using other organisms of different trophic levels, as well as analysis of sediment toxicity are recommended to confirm the patterns found with M. Juniae. However, the results indicate the necessity for implementation and improvement of sewage treatment systems affluent to the Potengi s estuary
Resumo:
The present work studied the problems faced riverine populations of the estuary Potengi, detaching its perception with regard to the environment, as well as in the evaluation of the institucional arrangement that acts in the place. Questionnaires were used in five riverine communities and conducted interviews with agents of public agencies and colonies of fishermen. There is little understanding of the needing to preserve and weakness in the application of the regulation mechanisms
Resumo:
This work was developed in the Potengi river estuary, northern coastal city of Natal, located in the State of Rio Grande do Norte. The objective was to study the dynamics of Multitemporal Space in that estuary, however, analyze how this environment has behaved during the years 1988, 1994 and 2006. The definition of that, there was the fact that during that period, which occurred in that area and more intensive space exploration to practice economic activities as well as a greater and more rapid expansion of urban area. This study was supported by the Remote Sensing, who have been shown today, as an efficient analysis of the environmental studies, through geoprocessing techniques. From the performed analysis it was found that occurred during the period of study (1988 to 2006), a huge change in the design of the estuary of Potengi river. The figures showed the area of vegetation was decreased 65.22%, the deforested area increased by 70.44% and the shrimp activity grow 452.07% and the urban area was increased in 52.65% along that period described. Considering the numbers shown there that the process of occupying space in that area requires attention, because it is an environment that represents a huge contribution to the ecological balance.
Resumo:
The Potengi River estuary has been affected by various anthropogenic factors over the years, as periodic dredging, industrial and domestic waste, traffic and other factors, causing various environmental disasters, including the notorious ecological accident in July 2007, which covered the municipalities of São Gonçalo do Amarante, Macaíba and Natal. Foraminifera serve as viable study tools in these environments; they are able to identify ecologically stressed environments, pointing out hydrographic changes and depositional environments in estuaries. The necessity to check the differences in environmental gradients in places anthropically impacted in Potengi River and adjacent inner shelf through species of foraminifera, and, the responses of these organisms to physical, chemical and geological factors is to provide baseline in the diagnosis of environments. The results show the dominance of opportunistic Ammonia tepida, Bolivina striatula, Quinqueloculina patagonica and Q. miletti especially in regions close to shrimp farms and Baldo Channel sewage in fine grain environments; and Q. lamarckiana indicates penetration of the saline waters in Potengi River. The occurrence of low-salinity tolerant foraminiferal species typical of mangrove environments as Trochammina inflata and T. squamata in Potengi River Channel suggest they probably could have been transported from mangrove area near the Potengi river mouth to the inner shelf regions. These findings suggest Potengi River is able to export mixohaline and mangrove organisms to inner shelf. Two distinct environments were observed, the outermost area is more influenced by marine influence and the innermost area is less influenced. Calcareous and agglutinated species dominate Potengi River, while mouth and inner shelf areas are dominated by calcareous, agglutinated and porcelaneous species, which are typical of highly saline and hydrodynamic environments and the contributive factors that controls foraminiferal distribution were balance of marine and freshwater currents, grain size, availability of CaCO3 and organic matter.
Resumo:
The Potengi River estuary has been affected by various anthropogenic factors over the years, as periodic dredging, industrial and domestic waste, traffic and other factors, causing various environmental disasters, including the notorious ecological accident in July 2007, which covered the municipalities of São Gonçalo do Amarante, Macaíba and Natal. Foraminifera serve as viable study tools in these environments; they are able to identify ecologically stressed environments, pointing out hydrographic changes and depositional environments in estuaries. The necessity to check the differences in environmental gradients in places anthropically impacted in Potengi River and adjacent inner shelf through species of foraminifera, and, the responses of these organisms to physical, chemical and geological factors is to provide baseline in the diagnosis of environments. The results show the dominance of opportunistic Ammonia tepida, Bolivina striatula, Quinqueloculina patagonica and Q. miletti especially in regions close to shrimp farms and Baldo Channel sewage in fine grain environments; and Q. lamarckiana indicates penetration of the saline waters in Potengi River. The occurrence of low-salinity tolerant foraminiferal species typical of mangrove environments as Trochammina inflata and T. squamata in Potengi River Channel suggest they probably could have been transported from mangrove area near the Potengi river mouth to the inner shelf regions. These findings suggest Potengi River is able to export mixohaline and mangrove organisms to inner shelf. Two distinct environments were observed, the outermost area is more influenced by marine influence and the innermost area is less influenced. Calcareous and agglutinated species dominate Potengi River, while mouth and inner shelf areas are dominated by calcareous, agglutinated and porcelaneous species, which are typical of highly saline and hydrodynamic environments and the contributive factors that controls foraminiferal distribution were balance of marine and freshwater currents, grain size, availability of CaCO3 and organic matter.
Resumo:
Untreated effluents that reach surface water affect the aquatic life and humans. This study aimed to evaluate the wastewater s toxicity (municipal, industrial and shrimp pond effluents) released in the Estuarine Complex of Jundiaí- Potengi, Natal/RN, through chronic quantitative e qualitative toxicity tests using the test organism Mysidopsis Juniae, CRUSTACEA, MYSIDACEA (Silva, 1979). For this, a new methodology for viewing chronic effects on organisms of M. juniae was used (only renewal), based on another existing methodology to another testorganism very similar to M. Juniae, the M. Bahia (daily renewal).Toxicity tests 7 days duration were used for detecting effects on the survival and fecundity in M. juniae. Lethal Concentration 50% (LC50%) was determined by the Trimmed Spearman-Karber; Inhibition Concentration 50% (IC50%) in fecundity was determined by Linear Interpolation. ANOVA (One Way) tests (p = 0.05) were used to determinate the No Observed Effect Concentration (NOEC) and Low Observed Effect Concentration (LOEC). Effluents flows were measured and the toxic load of the effluents was estimated. Multivariate analysis - Principal Component Analysis (PCA) and Correspondence Analysis (CA) - identified the physic-chemical parameters better explain the patterns of toxicity found in survival and fecundity of M. juniae. We verified the feasibility of applying the only renewal system in chronic tests with M. Juniae. Most efluentes proved toxic on the survival and fecundity of M. Juniae, except for some shrimp pond effluents. The most toxic effluent was ETE Lagoa Aerada (LC50, 6.24%; IC50, 4.82%), ETE Quintas (LC50, 5.85%), Giselda Trigueiro Hospital (LC50, 2.05%), CLAN (LC50, 2.14%) and COTEMINAS (LC50, IC50 and 38.51%, 6.94%). The greatest toxic load was originated from ETE inefficient high flow effluents, textile effluents and CLAN. The organic load was related to the toxic effects of wastewater and hospital effluents in survival of M. Juniae, as well as heavy metals, total residual chlorine and phenols. In industrial effluents was found relationship between toxicity and organic load, phenols, oils and greases and benzene. The effects on fertility were related, in turn, with chlorine and heavy metals. Toxicity tests using other organisms of different trophic levels, as well as analysis of sediment toxicity are recommended to confirm the patterns found with M. Juniae. However, the results indicate the necessity for implementation and improvement of sewage treatment systems affluent to the Potengi s estuary
Resumo:
Recent studies concerning the landscape have investigated the most important activities that contribute for its modification and have tried to better understand the society through the marks left by its quotidian. It is understood that singular landscapes constitute the cultural patrimonies of the cities, once they are part of the daily life of the citizens and are present in their social representations. Some contemporary authors defend the preservation of the natural and urban landscape trying, specially, to keep its importance for the local population. Natal is a city where the ambient qualities are well defined and known by the beauty of the area where it is located. Situated just between a river and the sea, the city grew following its geographic characteristics. The Potengi River, the Atlantic Ocean and the vast dunes ecosystem represented natural limits to the urban expansion; at the same time they have favored the development of a landscape pattern marked by the dialectic between the natural elements and the human interventions. However, this relationship changed after the intensification of the high rising development process that took place since the 1960s. The urban legislation tried to preserve the features of the local landscape delimiting Areas for Controlling Building High , destined to protect the scenic value of some parts of the city. On the other hand, the civil construction sector has made constant pressure in sense to abolish or to modify this legal instrument, aiming profits that have increased, in the 1990s, because of the consumption and the qualification of the urban space for tourist activities. It is necessary the raising of new elements to stimulate the quarrel about the landscape preservation, the process of the urban space production and the best way for the legislation implementation. This work tries to raise elements about the subject at local level, in sense to use Natal City experience to contribute for the formulation of indicators to raise the question about the lack of measure for subjective values, for example the cultural and affective value of the landscape. The natural elements inserted in the urban profile, represent strong visual references and supply identity to the town; they are part of the collective imaginary and are detached in the social context of the city. Then, why the preservation of the landscape, that estimates the improvement in the quality of life, is not enough to justify the controlling building high already previewed as part of Natal City Legislation? These questions send us to the approach of the landscape, as a community patrimony, alerting that some of its significant esthetics attributes must be preserved as a legacy for the future generations
Resumo:
It is a case study that reports the construction of metal truss bridge in the river Potengi in Natal, Rio Grande do Norte, between the years 1912 and 1916. From testimonials on steel bridges in Brazil and worldwide including foundations. Documentary research from procurement of projects and contracts was performed. A chronology of construction, with a description of the equipment used and its original budget with the Brazilian government. Still, we used interviews and surveys with experimental sampling / testimonies, laboratory tests. This study aims to analyze historically and technically the Bridge over the River Potengi, emphasizing primarily the construction process, the qualities and characteristics of the materials used and the technological, chemical, mineralogical and microstructural properties of cement and concrete used in its construction. Taking as conclusions that cements pozolônicos ensured a good durability to the concrete in a hundred-year period and that the solution employed with the compressed air caissons was right
Resumo:
The city of Natal-RN is constructed on dune areas with wavy relives softly waved and green areas that help to keep a pleasant climate, amongst these is distinguished field Pirangi-Potengi the dune with the areas of San Vale and Lagoinha. These environments are being substituted gradual for property and other workmanships of engineering on behalf of the urban expansion. This study the elaboration of a geoambiental mapping of Field had as objective generality Pirangi-Potengi the Dune with emphasis the San Vale and Lagoinha in Natal-RN. The done mapping had as objective specific to elaborate a vegetation map, a map of registers in cadastre of ambient problems to dunes, a map of flooding susceptibility, a map of vulnerability to the underground water contamination and a map of use and occupation of the ground. Of the carried through analysis, the area in study reveals sufficiently degraded, remaining only few green areas and dunares, as well as, the vulnerable presence of areas of vulnerability in floods and areas the contamination of the water-bearing one. The gotten results allow to affirm that this type of mapping, is of great importance for analysis and evaluation of the environment of the city