Navegando por Assunto "Aspectos ambientais"

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Acesso aberto (Open Access)
Avaliação ambiental dos recursos hídricos, solos e sedimentos na área de abrangência do depósito de resíduos sólidos do Aurá - Belém-PA
(Universidade Federal do Pará, 2002-03-27) PIRATOBA MORALES, Gundisalvo; FENZL, Norbert; http://lattes.cnpq.br/6834981018643186
With 1.754.099 inhabitants, the municipality of Belém produces roughly 1,200 tons per day of all kinds of waste, which are deposited in a landfill known as Lixão do Aurá, bordering the municipality of Ananindeua. During the past 11 years, this area has been accumulating approximately three million and two-hundred thousand tons of solid waste, transforming that place into a permanent local source of anthropogenic pollution, altering environmental conditions and resources around the whole area surrounding it. A Vertical Electrical Resistivity Sounding (VERS) procedure, conducted in the area before it was transformed into the landfill (1991), compared with the measures taken eight years later (1998), show that the land resistance has considerably dropped, with values in some cases — 109 times smaller than the original ones, thus indicating that the layers have been affected by the leach from waste decay. Fifteen profiles were conducted in the area, using the electrical imaging system, allowing us to confirm the (VERS) results, with evidences that the underground water has been affected by the infiltration and by the leachate vertical and horizontal movements. The hydro geological characteristics in the area show that the local predominant type of aquifer is of the free kind, locally confined, with hydraulic gradient of approximately 0.695%, effective porosity of 28%, permeability coefficient ranging from 1.1 x 10-3 to 0.9 x 10-4 cm/s, and underground flows running north/south towards the Guamá River, at approximately 14.79 m/year. A multivariate statistical analysis has shown that superficial water samples, collected simultaneously at three control points, during one tide cycle, regardless of the season, portray totaily different behaviors, indicating that superficial water resources are being affected by the superficial movement of leachate. With the concentration value figures for each of the leachate parameters (pH, conductivity, alkalinity, ammonia, total organic carbon, chloride, sodium, potassium, calcium, and magnesia), plus the flow of the Aurá River at the control point near the Guamá River, it is possible to estimate the quantity of pollutants that the solid waste landfill sends into the water system. During one tide cycle, in the dry season, the solid waste landfill deposits approximately 13,115 kg of chloride, 417 kg of ammonia, and 129,767 kg of salts in the local water system. For the underground waters, the multivariate statistics showed that the samples collected In the monitoring wells in the area show significant differences, indicating that the wells located downstream have been affected by the leachate. The presence of sand layers right in the area where solid waste is deposited allows for the vertical and horizontal movement of the different pollutants originated by the leachate. The heavy metais anaiyses, conducted under the sequential extraction methodology, showed percentages in the geochemical phases potentially bio-available in the studied soil and sediment samples. In the soil samples, the potentially bio-available fraction (replace, reduce, and organic geochemistry phases) contained an average of 32% of the total Cadmium (Cd), 11.8% of the total Chromium (Cr), 23% of the total Copper (Cu), 12.32% of the total Nickel (Ni), 43.1% of the total Lead (Pb), and 31.01% of the total Zinc. The potentially bio-available phases percentage in the sediments of the area was greater than the ones found in the soil samples. In these sediments, the quantity of heavy metais in the potentially bio-available fraction, shown higher values during the dry season than during the rainy season; for instance, 33% of the total Cd measured during the rainy season increased to 37% in the dry season; Pb increased from 61 to 70%; Zn, from 51 to 54%, among others. The metais analyzed by total attack in the soil samples, compared with the sandstone backgrounds, indicate that the Fe (3.1%), Cu (18.5 ppm), Ni (10.1 ppm), Pb (69.5 ppm), Cr (76 ppm), and Cd (>1 ppm) are above normal standards. In the case of sediment samples, the EPA background values (total concentration) would be moderately polluted by Cr (average 64.6 ppm) and heavily polluted by Fe (3.8%) and Mn (600 ppm). These results show that the sediments were not polluted by Pb and Zn. Considering the potentially bio-available phase and using the tool provided by a Geographic Information System (GIS), we can say that, during the rainy season, the sediment samples were not polluted by Cr (potentially bio-available fraction smaller than 20% of the total) were highly polluted by Pb and Zn (PBD higher than 50%), and moderately polluted by Cu, Ni, and Cd (PBD between 20 and 50%).
Acesso aberto (Open Access)
Avaliação do tratamento de efluentes da indústria de alumina no contexto dos impactos da mineração na Amazônia Oriental
(Universidade Federal do Pará, 2014-06-26) BARBOSA, Renata Kelly da Costa; BERRÊDO, José Francisco; http://lattes.cnpq.br/1338038101910673; FRANÇA, Silvia Cristina Alves; http://lattes.cnpq.br/9463680545957601
The state of Pará has one of the world's largest mineral reserves, and bauxite, the rock from which aluminum is extracted is particularly plentiful here. However, the process for obtaining aluminum produces impactful environmental waste (red mud), a highly caustic residue. The general objective of this study was to characterize the effluent (solid and liquid phases) generated by alumina refining, and to evaluate the efficiency of the DAF ( Dissolved Air Flotation) process in order to improve the quality of this, so that it might be possible to reuse the water. The observed results were as follows: the chromium concentration in Pará River is higher than the legal limit. The riverbed sediment has low bioavailability due to its characteristics of silt and fine sand, and is composed mainly of quartz. The collected phytoplankton and oysters near the refinery showed high levels of aluminum and other chemical elements (Ca, Co, Cu, Mg and S), especially when compared with those from the control point. The red mud is composed of fine particles of chemical composition 50% Fe2O3 and Al2O3. DAF tests showed satisfactory results with solids removal efficiency reaching 99% with T-8 and 99.4% in the E-4f, with final turbidity values less than reached 8.5 NTU. The recycle ratio and the concentration of flocculant were shown to be important variables in the experiments, and showed exhibited better results in the removal efficiency of solids. Acute and chronic ecotoxicological tests showed good results in the efficiency of wastewater treatment by using the DAF. It is expected that this study will contribute to scientific knowledge, and may serve as an alternative for the treatment of effluent from the alumina industry. Moreover, the study reached important results that can help improve the quality of waste water and its reuse in the manufacturing process, which can reduce water consumption and environmental risks.
Acesso aberto (Open Access)
Entre banzeiros e remansos: memórias da professora Ionete da Silveira Gama
(Universidade Federal do Pará, 2023-04-13) RODRIGUES, Josivana de Castro; SILVA, Carlos Aldemir Farias da; http://lattes.cnpq.br/7226908910873590; https://orcid.org/0000-0001-5463-1316
Memory is humans’ ability to preserve meaningful things that happened in the past. By making us remember events, it allows us to tread again important pathways of collective and individual human trajectories. In this dissertation, our objective is to recollect fragments of the memories of a teacher, Ionete da Silveira Gama, in order to understand how her life experiences influenced her music, and how did it relate to primary school contents she taught in riverside cities in the countryside of the state of Pará. Her memories as a teacher make us understand how important it is to use work methodologies which include the sociocultural experiences of students to teach contents from different school subjects, from an interdisciplinary standpoint. We ask ourselves how does Ionete Gama’s music blend Amazonian cultural elements with the natural sciences in an interdisciplinary perspective, and how can it be connected to the themes taught in Primary School? To reach this goal, we recorded fragments of her life’s story through interviews, so as to understand her trajectory, emphasizing the reminiscences of her childhood by the Amazonian riverside and of the years she dedicated to teaching river dwellers. These interviews were written down and became an (auto)biographical narrative that is complimented by her images and documents. In this dissertation, we give pride of place to six songs that refer to environmental aspects that are integral to the Amazonian culture and, based on them, we elaborated illustrated stories for children. The stories are aimed at the primary school level of education.
Acesso aberto (Open Access)
Fluxo de óxido nitroso (N2O) do solo em um sistema agroflorestal em Tomé Açu, nordeste do Pará
(Universidade Federal do Pará, 2013-08-14) SOUZA, Gisele Nerino Brito de; VASCONCELOS, Steel Silva; http://lattes.cnpq.br/0719395243841543
The study on the emission of nitrous oxide (N2O) from soil in agricultural systems contributes to the understanding of global climate change, which could aid in minimizing negative impacts on the environment. The importance of this gas due to its direct relationship with the global greenhouse effect and to stratospheric ozone depletion. Some agricultural practices performed in agroforestry systems, when managed correctly can help curb these negative impacts. The use of legumes in these systems has become increasingly common, but its relationship with N2O emissions is still not well understood. Given the importance of processes and factors contributing to the increase in N2O emissions, this study aimed to examine the contribution of legume species (Inga edulis Mart.) And non-legume (Theobroma cacao) in nitrous oxide emissions from soil to the atmosphere through the use of static cameras and different climatic characteristics in an agroforestry system in the city of Tome Açu northeastern state of Para the experiment was conducted in an area of agroforestry (SAF) located in Tome Acu ( PA ) ( 02 ° 33'38 , 5 " S , 48 ° 21'36 , 1 " W ) within the February/2013 August/2012, totaling 11 field campaigns, a fortnightly basis. Static chambers of circular type (diameter = 300 mm ) and rectangular ( 37.5 cm x 57 cm ) were used to determine the emission of N2O from the soil, with the aid of polypropylene syringes with a volume of 20 ml and transferred to flasks borosilicate. The N2O concentration was determined by gas chromatography using a gas chromatograph Varian CP 3800 gas model with an electron capture detector. The variation of N2O emissions were 2.74 to 42.54 mg N m-2 h-1 pulses to and from 1.65 to 30.46 mg N m-2 h- 1 for non-legumes. Higher emissions were observed in the wet season compared to the dry season. The gravimetric soil moisture, soil temperature and inventory of plant residues on the soil were the factors that most N2O emissions from the soil.