Banca de QUALIFICAÇÃO: Ygor Oliveira Sarmento Rodrigues

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : Ygor Oliveira Sarmento Rodrigues
DATE: 05/09/2024
TIME: 14:00
LOCAL: Videoconferencia
TITLE:

TOTAL MERCURY SPATIAL DISTRIBUTION IN RIVER WATERS AND ITS AUTOCORRELATION WITH LAND USE IN A NEOTROPICAL FLOODPLAIN

KEY WORDS:

Mercury; Brazilian Savannah; Ecological risk; Mass flow; Kriging.

PAGES: 18
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

Mercury (Hg) represents a public health problem worldwide and its availability in water poses the greatest ecological risks. In tropical regions, the release of domestic and industrial wastes, and land use and land cover are recognized as the main anthropogenic sources of Hg to water bodies. The present work reports the dynamics of transport and accumulation, as well as the level of Hg contamination in surface water and fine and suspended sediments of the Araguaia River, in central Brazil. This river is one of the main river systems in South America and its basin is subject to an increase in land use activities, in particular the exploitation of agricultural activities. Surface water and fine and suspended sediment samples were collected from a total of 45 sampling units along 335 km of
the river. Quantification of total Hg (HgT) in the surface water samples was by atomic fluorescence (CVAFS) and of the sediments were performed by atomic absorption (CVAAS). A principal component analysis was applied to analyze the association between HgT concentrations, environmental conditions and land use intensity. Cokriging was used to characterize the spatial distribution of HgT and the ecological risks associated with environmental conditions and land use intensity. Due to the greater presence of clay minerals, iron and aluminum oxides, and organic matter, it would be understandable that fine sediments would have the highest concentrations of HgT; followed by suspended sediments because of the volume of silt and particulate matter carried into the water body. The lowest concentration of HgT may be in surface waters due to dissolution of the metal at this interface. Higher concentrations of HgT are expected in regions with the highest intensity of land use, and higher mass flow in the vicinity of Bananal Island due to the direction of flow. With the help of geostatistical systems, it will be possible to better understand the dispersion of HgT in Araguaia River.

COMMITTEE MEMBERS:
Interna - 3049879 - ERINA VITORIO RODRIGUES
Presidente - 1412797 - JOSE VICENTE ELIAS BERNARDI
Externo ao Programa - 1122801 - JURANDIR RODRIGUES DE SOUZA - null