Navegando por Autor "MEIRA, Rose Caldas de Souza"

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Acesso aberto (Open Access)
Avaliação comparativa entre a estimativa do impacto gerado por efluentes domésticos de assentamentos espontâneos e de ocupação formal na bacia do Tucunduba em Belém - Pará
(Universidade Federal do Pará, 2008-04-18) MEIRA, Rose Caldas de Souza; CARDOSO, Ana Cláudia Duarte; http://lattes.cnpq.br/3138101153535395
The aim of this research is to present a comparative evaluation of environmental damage produced by different housing contexts whithin the same urban space, in a district of Belém municipality, called Guamá, one represents a formal context José Bonifácio Av., and other represents the informally produced space Riacho Doce community. This evaluation has taken into account the following features, namely: per capita consumption of water, per capita consumption of sewage, universality and equality of the provision of sanitation services (water supply, sewage), charging for water supply, quality and accessibility of services, housing context, socio-environmental features, in order to characterize the population living in those referred areas and finally to estimate the organic charge (Tonne / day) and the flux of effluents generated in spontaneous settlements and in a consolidated urban area, with the aim of identifying which housing context presents greater potential for impact in terms of flow generation and organic charge on effluents receiving basin, in this case the Tucunduba basin. Although the results are relatively close values, in the area of the Riacho Doce the flux of sewage is estimated as 44,38 m3/ day and organic charge is estimated as 13,31 Kg of DBO/day, whereas in the area of the José Bonifácio the flux of sewage is estimated as 43,06 m3/day and organic charge is estimated as Kg of DBO /day. It was possible to verify from results, that there are differences between the environmental impacts yield by the two areas above referred on the receiving basin of river Tucunduba, being that the environmental impact generated by Riacho Doce, where the population remains in contact with the effluent and under a greater sanitary vulnerability, since that effluents of Jose Bonifacio Av. are guided by drainage system and its organic charge is diluted by flux of rainwater to reach Tucunduba River (removing the contamination of its source) while the effluents from Riacho Doce are launched in natura directely below houses and in Tucunduba River.
Acesso aberto (Open Access)
Otimização da síntese de estruvita e seus análogos visando a recuperação de fósforo, magnésio, nitrogênio e potássio de águas residuais
(Universidade Federal do Pará, 2020-03-13) MEIRA, Rose Caldas de Souza; PAZ, Simone Patrícia Aranha da; 5376678084716817; CORRÊA, José Augusto Martins; 6527800269860568
Domestic and industrial wastewaters, untreated or minimally treated, are rich in macronutrients that can cause eutrophication if they are released without treatment into the environment. Currently, domestic sewage has been studied as a material source for nutrient recovery, such as struvite precipitation. Struvite is an ammonium-magnesium phosphate hexahydrated (NH4MgPO4.6H2O) formed in equimolar proportions in alkaline aqueous systems. Depending on formation physicochemical conditions (ion concentration, pH and temperature), precipitation of both struvite and the named analogous struvites, with several possibilities of isomorphic substitutions, can occur. The present work aimed the synthesis, characterization, and optimization of struvite crystallization and its analogues for nutrient recovery from wastewater solutions containing magnesium (MgCl2.6H2O), phosphorus (K2HPO4) and nitrogen (NH4Cl); and also perform the mineralogical quantification of the struvite phases, the detailing of crystallochemical aspects, including the determination of the chemical formula of the best synthesis condition obtained using the combined Rietveld refinement method and Internal Standard of the Fullprof program with the FULL graphical interface. The statistical plans were carried out: I - Tree Diagram and II - 23 Full Factorial Design (DOE), duplicated with four central points, using the response surface methodology and the global desirability function to establish the most significant responses for struvite yield. The variables studied were pH (10, 11 and 12), phosphorus concentration (100, 200, and 300 mg L-1), and molar ratio Mg: P: N (1: 1: 1; 1: 1: 1.5; 1: 1: 2), with three response variables: (1) enthalpy variation (ΔH) of decomposition peaks of synthesis products by differential scanning calorimetry (DSC); (2) infrared percent transmittance (% T – IR) at 1073.17 position, which refers to the asymmetric stretching band of the P-O bond from phosphate (PO4 3-) and (3) variation of total mass loss Δm (%) in thermogravimetry (TG). The most significant factors were revealed (pH 10, P concentration = 300 mg L-1 and Mg:P:N molar ratio = 1: 1: 2). The most favorable condition for struvite precipitation, called condition 01 and duplicated (A, B, C, and D), was investigated in details. For this condition, the Rietveld refinement was performed. This technique proved that the generated struvites were of the analogous type with ammonium (NH4 +) substitution by potassium ion (K+). It was quantified an amount of 20.34% of struvite and 79.66% of analogous struvite (K-struvite). Mineralogical quantification was performed using the Rietveld refinement technique combined with the Internal Standard method, the obtained data were: 74.3% of analogous struvite, 16.6% of struvite, and 9.1% of amorphous material. Results were ratified by the analytical techniques XRF, SEM / EDS, DSC / TG, FTIR, and SSABET which proved to be efficient for the confirmation of the multiple phases identified in analogous struvites revealed by the Rietveld refinement.