Navegando por Assunto "River pollution"

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Acesso aberto (Open Access)
Especiação do fósforo em rios urbanos: um estudo de caso dos rios Tucunduba e Tamandaré, Belém/Pará
(Universidade Federal do Pará, 2023-05-24) COIMBRA, Marcus Vinicius Rodrigues; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; https://orcid.org/0000-0001-9449-7043
Phosphorus (P) is a bioliminating macronutrient that plays an essential role in regulating ecosystem functions and primary productivity in marine and coastal environments. However, when in excessive concentrations, P assumes the role of a pollutant, negatively influencing the ecosystem and causing eutrophication. In Brazil, the problem is maximized in urban centers cut by canals, where there is an intensification of the process of changing the natural conditions of the environment. The speciation of P associated with hydrodynamic processes and the type of urbanization of the environment allows identifying the eutrophication status of these environments. Therefore, the present study seeks to promote understanding of the dynamics of P speciation in two urban rivers, the Tucunduba and Tamandaré rivers, located in the metropolitan region of Belém (Northern Brazil), with the objective of evaluating whether there is variation in P speciation. phosphorus in urban rivers at different time scales. To this end, samples of suspended particulate matter (SPM) were carried out using two different methodologies: the horizontal flow trap (portable traps) and the vertical flow trap (fixed traps). For the extraction of P, the sequential extraction method SEDEX was adopted, which allowed the extraction of five forms: P-Ex, P-Fe, P-Au, PDe and P-Org, in addition to P-Bio. In the Tucunduba river, Total-P concentrations ranged from 20.52 to 100.78 μmol.g-1, with predominance of the P-Fe fraction. In the Tamandaré River, concentrations ranged from 42.36 to 173.88 μmol.g-1 with P-Au predominance. Thus, it was possible to verify that the urban rivers Tucunduba and Tamandaré have high concentrations of P and its species. With these data, it is clear the need to deepen this type of study in these rivers and other urban rivers present in Belém, as well as the need for policies aimed at the recovery and preservation of these, in order to mitigate the problem involving phosphorus and restore the capacity ecosystems of these environments.
Acesso aberto (Open Access)
Transporte de resíduos sólidos flutuantes em rios urbanos dominados por maré na região Norte do Brasil
(Universidade Federal do Pará, 2021-07-07) ROSA, Gabriel Pompeu; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; https://orcid.org/0000-0001-9449-7043
The rivers that cut through metropolises are considered important ways for the waste generated on the continents to be transported to the oceans. Estimates of waste flows in rivers in the Amazon coastal zone remain uncertain due to the influence of hydrodynamic processes (tide, currents and flow), and above all, the lack of data on the type and amount of solid waste floating in the rivers. Therefore, the main objective of this study was to quantify and estimate the fluctuating waste fluxes at different time scales in tidaldominated rivers of the Amazonian coastal zone. Visual quantification took place over 12 hours (6 to 6 pm) in the flood and ebb tide stages, in the dry and rainy periods, in the rivers Acará, Guamá, Guajará, Tucunduba and Tamandaré. The estimate of waste transport in different tidal stages and seasonal periods was calculated considering the amount of waste in a time interval (hour, month and year). A total of 19,654 solid waste was quantified in the rivers studied, 71% of which was plastic materials. The residues from the rivers that cut through Belém (Tucunduba and Tamandaré) are exported to the rivers that surround the capital, while in these rivers, the residues present a bidirectional flow, suggesting imprisonment reflecting the influence of hydrodynamic processes (tidal current and flow). This study presents the first estimate of transport in rivers on the coast of Pará based on real observations, indicating an estimate of annual transport that varies between 3 and 549 tons/year.