968 resultados para urban water bodies


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The contamination by metal ions has been occurring for decades through the introduction of liquid effluent not treated, mainly from industrial activities, rivers and lakes, affecting water quality. For that the effluent can be disposed in water bodies, environmental standards require that they be adequately addressed, so that the concentration of metals does not exceed the limits of standard conditions of release in the receptor. Several methods for wastewater treatment have been reported in the literature, but many of them are high cost and low efficiency. The adsorption process has been used as effective for removal of metal ions. This paper presents studies to evaluate the potential of perlite as an adsorbent for removing metals in model solution. Perlite, in its natural form (NP) and expanded (EP), was characterized by X-ray fluorescence, X-ray diffraction, surface area analysis using nitrogen adsorption (BET method), scanning electron microscopy and Fourier transform infrared spectroscopy. The physical characteristic and chemical composition of the material presented were appropriate for the study of adsorption. Adsorption experiments by the method of finite bath for model solutions of metal ions Cr3+, Cu2+, Mn2+ and Ni2+ were carried out in order to study the effect of pH, mass of the adsorbent and the contact time on removal of ions in solution. The results showed that perlite has good adsorption capacity. The NP has higher adsorption capacity (mg g-1) than the EP. According to the values of the constant of Langmuir qm (mg g-1), the maximum capacity of the monolayer was obtained and in terms of proportion of mass, we found the following order experimental adsorption: Cr3+ (2.194 mg g- 1) > Ni2+ (0.585 mg g-1) > Mn2+ (0.515 mg g-1) > Cu2+ (0.513 mg g-1) and Cr3+ (1.934 mg g-1)> Ni2+ (0.514 mg g-1) > Cu2+ (0.421 mg g-1) > Mn2+ (0.364 mg g-1) on the NP and EP, respectively. The experimental data were best fitted the Langmuir model compared to Freundlich for Cu2+, Mn2+ and Ni2+. However, for the Cr3+, both models fit the experimental data

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The semi-arid Northeast region are coming through changes since its formation causing changes in the landscape and increased degradation. The economic dynamics which was established at the Potiguar semiarid had for a long time settled in livestock, subsistence agriculture and cotton, however, these economies decline from the year 1970. Thus, the Potiguar spaces are undergoing by a process of space reordering marked by the growth of agricultural activities and the process of urbanization. In the Potiguar western region these changes weaken significantly transform the landscape. In these areas, the process of urbanization and agricultural activities have caused changes in the hinterland landscape changing the natural dynamics of the caatinga biome that has been subject to negative interference with the indiscriminate removal of vegetation. In this case, the specific study area of the watershed of Cajazeiras Creek located in the cities of Pau dos Ferros, Água Nova, Encanto and Rafael Fernandes, changes in the landscape has led to degradation and environmental fragility. From this perspective, the research objective is to assess the dynamics of the landscape of the watershed of Cajazeiras Creek, semiarid region of the state of Rio Grande do Norte, identifying the degrading factors, the most degraded areas and/or susceptible to degradation and environmental fragility. The research investigated the phenomena of light geosystems theory that emphasizes the integration of elements in shaping the landscape. During this reporting period, it was carried out exploratory and bibliographical research, and geoprocessing techniques to assess the social and environmental conditions of the researched area and its environmental fragility. To do so, first, it was made an multitemporal analisis on the basis of the years 1984, 1996 and 2009 demonstrating that the dynamics of use and land cover in the watershed of Cajazeiras Creek showed a significant change in the landscape, especially in the caatinga vegetation. This has been recovering in various areas of the watershed, especially in its upper course in the mountains of Bom Sera, in Encanto city. The analysis showed the need to develop policies and programs for the maintenance, restoration and preservation of the caatinga vegetation of the river network and of water bodies. In addition, it was identified the most degraded areas of the watershed, environmental fragility and potential emerging that take into account the landscape components such as climate, topography, geology, pedology, geomorphology and the use and occupation of the soil in an integrated manner. The results show that the landscape of the watershed has medium and high environmental fragility throughout its area, especially on the banks of the river network provided by the use and occupation of the soil in an inadequate way with the environmental conditions of the watershed

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A descriptive analysis of the responses of plankton from lakes lateral to a river in its mouth zone into a tropical reservoir to water level variations is presented. Three situations were reported: 1) a comparison of species richness and diversity and of algae population abundance in prolonged drought and in periods of connection of lakes to the river, 2) the spatial distribution of abundance and richness of Rotifera species in four isolated water bodies formed by fragmentation of a lateral lake during a period of prolonged drought and in the same areas during a period of integrity as an ecosystem, 3) the variability of total zooplankton and Cladocera densities at the end of the isolation period of a lateral lake and after the recovery of connection with the river and in a year of continuous connection with the lotic ecosystem. Various idiosyncrasies were observed in connected lateral lakes, like the surface hydrologic connectivity, a primary factor in species richness modifcations and a secondary controlling factor of plankton abundance. Underground hydrologic connectivity, through the river[forward arrow] lake water fux during the high-water period and lake [forward arrow] river during drought period, appears to have an important role in richness and abundance variations of planktonic populations in the lake isolated from the river.

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

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O bioma Cerrado encontra-se descaracterizado e menos de três por cento de suas áreas originais está legalmente protegida. A anurofauna desse bioma não é muito rica quando comparado a outros biomas, porém há um grande número de espécies endêmicas. Aqui apresentamos uma lista de espécies de anuros registrados em uma lagoa em área de cerrado aberto do município de Borebi, região Centro-Oeste do estado de São Paulo, sudeste do Brasil. Durante 24 meses de estudo (2008 e 2009) caracterizamos a distribuição das espécies na lagoa estudada e descrevemos a variação sazonal das espécies. Foram registradas 27 espécies pertencentes a seis famílias: Bufonidae (duas espécies), Cycloramphidae (uma espécie), Hylidae (13 espécies), Leiuperidae (quatro espécies), Leptodactylidae (cinco espécies) e Microhylidae (duas espécies). A riqueza de espécies e abundância estiveram relacionadas com a precipitação. Dendropsophus minutus foi a espécie mais abundante e com registro de vocalização durante o ano inteiro. Rhinella ornata e Odontophrynus americanus foram restritas ao período seco e frio (abril a agosto). As outras espécies tiveram seu período de maior atividade nos meses chuvosos e quentes (setembro a março). A ocupação da lagoa variou com o tipo de vegetação e conforme a variação do seu volume de água, principalmente nos período de estiagem. A alta riqueza e abundância de anuros da lagoa pode ser resultado da ausência de peixes predadores, dos diversos tipos de microambientes do local e da ausência de outros corpos d'água próximos.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Aquaculture effluents are enriched by nitrogen, phosphorus and organic matter and contribute to increase eutrophication of the receiving water bodies and reduction or change in biodiversity. To reduce effluent loading is important to formulate highly digestible diets with lower nutrient levels. In addition, it is necessary to treat effluents to attend to new legislation demands and the pressure of environmentalist. This review of the aquaculture activities and its impacts on the environmental is divided into fourth main subjects. The first is the way in which aquaculture affects the environmental through the consumption of materials and energy. The second is how aquaculture can affect the environmental directly, particularly through the effluents. The third is on the systems for treatment of aquaculture effluents with aquatic macrophytes. The fourth part is how aquaculture can be developed of sustainable form is on the systems for treatment of aquaculture effluents with aquatic macrophytes.

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Our objective was to evaluate the impacts caused on pond water quality by maintenance of Macrobrachium rosenbergii broodstock. During eight weeks we determined pH, dissolved oxygen (DO), conductivity, turbidity, particulate suspended material (PSM), nitrogen (N) and phosphorus (P), all in inlet and effluent water. All variables presented higher values in the effluent, except OD. N-ammoniacal concentration (0.013 mg L(-1)) was 2.7 times higher in the effluent pond; NO(2)-N (0.019 mg L(-1)), 2.3; NO(3)-N (0.139 mu g L(-1)), 1.8; PO(4)-P (0.065 mg L(-1)), 7.2; and DP (0,104 mg L(-1)), 4.9 times higher. For TKN (0.67 mg L(-1)) and TP (0.235 mg L(-1)) the values in the pond effluent represent an increase of 0.27 mg L(-1) and 0.175 mg L(-1), respectively. The maintenance of M. rosenbergii broodstock increase the nutrient concentrations, mainly TP, prevent effluent pond released into receiving water bodies on 1, 2 and 3 classes of the CONAMA N degrees 357 Resolution.

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

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

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

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The Estacao Ecologica de Jata comprises one of the largest mesophytic semideciduous forest and savanna remnants in the state of São Paulo. However, anuran surveys on this site have not been registered in the literature. As result of an exploratory survey conducted in water bodies in the mesophytic semideciduous forest and surroundings in December 2006, we recorded 21 anuran species belonging to five families and 10 genera. These findings contribute to the knowledge of the anuran fauna associated to the mesophytic semideciduous forest of São Paulo state, Brazil.

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This investigation was carried out within the Parana sedimentary basin, Brazil, and involved the sampling of sludge and residuary waters that were collected from reservoirs/decantation ponds settled in two tanneries situated at Patrocinio Paulista, São Paulo State Two samples from each tannery were collected, stored in appropriate flasks and transported to the LABIDRO for chemical analysis The LABIDRO (Laboratory of Isotopes and Hydrochemistry) of the Petrology Department at the Geosciences and Exacts Sciences Institute of UNESP is situated in Rio Claro city, about 240 km distant from the investigated area The data for residuary waters were compared with guideline values established by two different legislations (a) Rule No 12486 (NTA60) established in 20(th) October 1978 by São Paulo State for defining the potable water standards and (b) Register 997 published on 31 May 1976 that defines the permissible concentration limits in effluents to be released to water bodies (coastal, fresh or ground water) in São Paulo State The results confirmed that leather production is an activity with high environmental impact, despite improvements that may be achieved by tanneries

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

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