Avaliação preliminar da contaminação por BTEX, em água subterrânea de poços tubulares, no município de Natal-RN

Among the different types of pollutants typically attributed to human activities, the petroleum products are one of the most important because of its toxic potential. This toxicity is attributed to the presence of substances such as benzene and its derivatives are very toxic to the central nervous system of man, with chronic toxicity, even in small concentrations. The area chosen for study was the city of Natal, capital of Rio Grande do Norte, where samples were collected in six different areas in the city, comprising 10 wells located in the urban area, being carried out in three distinct periods March/2009, December / June/2010 and 2009, and were evaluated for contamination by volatile hydrocarbons (BTEX - benzene, toluene, ethylbenzene and xylenes), so this work aimed to assess the quality of groundwater wells that supply funding for public supply and trade in the urban area of the city of Natal, in Rio Grande do Norte, contributing to the environmental assessment of the municipality. The analysis of BTEX in water was performed according to EPA Method 8021b. Was used the technique of headspace (TriPlus TP100) coupled to high resolution gas chromatography with selective photoionization detector (PID) and flame ionization (FID) - model Trace GC Ultra, Thermo Electron Corporation brand. The procedure adopted allowed the detection of concentrations of the order of μg.L-1. Data analysis with respect to BTEX in groundwater in the area monitored so far, shows that water quality is still preserved, because it exceeds the limits imposed by the potability Resolution CONAMA Nº. 396, April 2008

Investigação e gerenciamento de áreas contaminadas por postos revendedores de combustíveis em Natal

Activities that have fuel subterranean storage system are considered potentially polluting fuels by CONAMA Resolution 273, due to the possibility of leak, outpouring and overflow of fuel into the ground. Being even more worrying when contaminate groundwater for public supply, as the case of Natal City. For this reason, the Public Ministry/RN, in partnership with UFRN, developed the project environmental suitability of Gas stations in Natal, of which 36% showed evidence of contamination. This paper describes the four stages of the management of contaminated areas: preliminary assessment of environmental liabilities, detailed confirmatory investigation of the contamination, risk analysis to human health (RBCA), as well as the remediation plan of degraded areas. Therefore it is presented a case study. For the area investigated has been proposed a mathematical method to estimate the volume of LNAPL by a free CAD software (ScketchUp) and compare it with the partition method for grid area. Were also performed 3D graphics designs of feathers contamination. Research results showed that passive benzene contamination in groundwater was 2791.77 μg/L, when the maximum allowed by CONAMA Resolution 420 is 5 μg/L which is the potability standards. The individual and cumulative risks were calculated from 4.4 x10-3, both above the limits of 1.0 x10-5 or by RBCA 1.0 x10-6 by the Public Ministry/RN. Corrective action points that remediation of dissolved phase benzene is expected to reach a concentration of 25 μg/L, based on carcinogenic risk for ingestion of groundwater by residents residential, diverging legislation. According to the proposed model, the volume of LNAPL using the ScketchUp was 17.59 m3, while by the grid partitioning method was 14.02 m3. Because of the low recovery, the expected removal of LNAPL is 11 years, if the multiphase extraction system installed in the enterprise is not optimized

Análise pelo Supply Chain Management da cadeia produtiva da castanha de caju no Rio Grande do Norte

This work presents the cashew nuts chain in the State of Rio Grande do Norte between 1960 and 2009. The main purpose of this research was to find the reason of the low productivity of the cashew nut in this state, identifying in the cashew's chain production the struggling points which were limiting the commerce of this product through the distribution network. Therefore, the Supply Chain Management was used as a logistic analysis methodology, focusing on relationships management between the nodes of this chain, from the producer until the final customer. Many problems were found: first, the precarious production conditions of the small producer don't lead to reach the demanded productivity by the market. The distance, the lack of communication of the small producers among themselves and an archaic way of dealing with their businesses, may be an explanatory reason for this problem, considering that those factors are the main elements which contribute for the weakening of the small producer placed in the productive chain. Another spotted point was that the business-oriented relationship between the producer and the local trader does not allow the small producer's economical development, which interferes in any technological investment to reach a good quality production that fulfills the market demand. And also, the fact that there is a tendency of the final costumer to require lower prices day-byday, forcing a pressure on the nodes transferring to the other and successively until arriving at the producer who inevitably is suffering the biggest impacts from this mentioned pressure.

Cadeia produtiva da farinha de mandioca na perspectiva da análise de filière e supply chain management :um estudo de caso das relações entre a agroindústria e a distribuição

This research aims to study the manioc flour productive chain in order to understand how the relationship between its segments happens, specially between the flour agroindustry and the distribuition. This research was made from a study of case that envolved three agro industries from the Potiguar wasteland and a company of food distribution. The filiére and the supply chain management analysis were applied to identify the functioning and the organization of the manioc flour productive chain. From the study of case it s noticed that the existing contracts, even the informal ones, has mutual benefits and it suggests that they be legalized

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

Remoção biológica de nitrato em água de abastecimento humano utilizando o endocarpo de coco como fonte de carbono

The groundwater quality has been compromised as a result of the intensification of human activities over the years. Groundwater contamination by nitrate is one of the effects of this degradation, a socio-environmental problem that affects many regions of the world and particular the city of Natal (RN). Developing techniques for nitrate removal in water is intended to eliminate or reduce the concentration of this compound, and those that involve biological processes have produced economic and environmental advantages. This study proposes a technology for biological removal of nitrate in water supply for humans, using the endocarp s coconut as a carbon source and bacteria support. The experiments were performed in pilot scale anoxic, testing different areas of the substrate surface. Results showed high rates nitrate removal during the monitoring period, noting the occurrence of denitrification after the beginning of system operation. The best performance was achieved in the treatment system containing substrate surface area increased, indicating that the decrease in the endocarp size contributed to increased bacterial activity, improving the ability to remove nitrate. About the quality analyzed aspects of water, it was found that the proposed technology has the potential water use for human consumption

Simulação numérica do fluxo hídrico subterrâneo na bacia hidrográfica do Rio Pitimbu RN

Urban centers in Pitimbu Watershed use significant groundwater sources for public supply. Therefore, studies in Dunas Barreiras aquifer are relevant to expand knowledge about it and help manage water resources in the region. An essential tool for this management is the numerical modeling of groundwater flow. In this work, we developed a groundwater flow model for Pitimbu Watershed, using the Visual Modflow, version 2.7.1., which uses finite difference method for solving the govern equation of the dynamics of groundwater flow. We carried out the numerical simulation of steady-state model for the entire region of the basin. The model was built in the geographical, geomorphological and hydrogeological study of the area, which defined the boundary conditions and the parameters required for the numerical calculation. Owing to unavailability of current data based on monitoring of the aquifer it was not possible to calibrate the model. However, the simulation results showed that the overall water balance approached zero, therefore satisfying the equation for the three-dimensional behavior of the head water in steady state. Variations in aquifer recharge data were made to verify the impact of this contribution on the water balance of the system, especially in the scenario in which recharge due to drains and sinks was removed. According to the results generated by Visual Modflow occurred significantly hydraulic head lowering, ranging from 16,4 to 82 feet of drawdown. With the results obtained, it can be said that modeling is performed as a valid tool for the management of water resources in Pitimbu River Basin, and to support new studies

Caracterização e avaliação do macro sistema urbano de distribuição de água de Natal RN

The aim of this study is to characterize and evaluate the Macro System of Regional Water Distribution Natal North (RNN) and Southern Regional Natal (RNS), covering 35% and 65% respectively of the Natal-RN City. The terms of the quality and quantity of water (surface and groundwater) were also evaluated in order to adjust the parameters that contribute to proper distribution and control in water reserves. The methodology of the work took place from collecting volumetric data of production capacity and distribution of the two treatment plants for Regional as well as the flow rates of wells. Yet the quantitative capacity of reservation, distribution and consumption of the main reservoirs, population numbers and consumption of members neighborhoods were collected. Data were tabulated and used in computational simulator EPANET to diagnose possible through the water balance, the offers and demands on the water supply system in the neighborhoods of the capital, linking them to specific distribution points. We also evaluated the wells in the levels of nitrate in water consumed. As a result it was found that some neighborhoods in the South Regional Natal, was ranked as critical supply situation: City of Hope, Lagoa Nova and Nova Descoberta, where demand exceeds supply. While in most Northern Regional Natal present deficiency in the supply system as: Lagoa Azul, the Parque dos Coqueiros, igapó, Amarante and Salinas. The rates of nitrate in the city were significant, but manageable with corrective and preventive measures. The averages were 12 mg /l-N in Candelária, 10 mg/l-N in Lagoa Nova, 9 mg/l-N in Satelite, 20 mg/l-N in Gramore and 15 mg/l-N in N. Sra. Apresentação. Therefore proper distribution of water abstracted and implementation of quality control ensures the supply required by the system, associated with preservation of Water Resources of the Metropolitan Region of Natal

Avaliação da genotoxicidade das águas do lençol freático sob a Universidade Federal do Rio Grande do Norte

The groundwater represents the most important freshwater supply of planet. Dailly, in all world a great amount of toxic and genotoxic material reaches the aquatic systems, mainly the aquifers. The Barreiras aquifer through of five water wells is responsible for the supplying of Universidade Federal do Rio Grande do Norte (UFRN). All water wells are polluted with nitrate and some heavy metals, two of them were disabled. The genotoxicity of groundwater samples from Barreiras Aquifer in UFRN was assessed using the Allium cepa test, the Ames test and the Salmonella typhymurium microsuspension test (Kado test). For the Allium cepa test the influence of the groundwater samples collected on macroscopic (root length, colour and form) and microscopic (root tip mitotic index, chromosome aberrations and micronucleus) parameters was examined. All water samples caused a significant increase of the chromosome and mitotic aberration frequency and reduction on the rooth growth compared to negative control. Bridges and chromosome stickness were the most frequent kind of aberration in dividing cells. Furthermore, breaks were also observed. No significant increase in the number of micronuclei was found in relation to the negative controls. For Ames test were used the Salmonella typhymurium strains TA98 and TA100 without metabolic activation, applying the direct method. Prior to the Kado test, organic fractions from the water samples were obtained through XAD resin concentration. The mutagenicity organic extracts were evaluated by Kado test using TA98 and TA100 strains, in the absence and presence of S9 mix (metabolic activation). The concentrations of seven heavy metal ions were measured in water samples, but only Ni, Cu and Cr levels exceeded the permissible maximum concentration for the natural reservoirs. The results obtained for mutagenic activity using the Ames test were negative in all raw water samples analyzed. Positive results in XAD4 extracts of water samples were obtained for TA98 in the presence of S9 mix for two stations. Concentrations of heavy metals and nitrate can be correlated with the toxicity and genotoxicity of water analyzed. The mutagenic effect detected with TA98 strain suggested that organic compounds (after metabolization) are involved with the mutagenicity detected in the samples analyzed. The data set obtained in this work indicated the presence of at least two classes of mutagens: organic and inorganic compounds