Banca de QUALIFICAÇÃO: SAMIR DOS SANTOS COSTA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : SAMIR DOS SANTOS COSTA
DATA : 24/11/2017
HORA: 08:30
LOCAL: Sala 1 PPGG
TÍTULO:

Geochemical Assessment of trace elements from Potengi River Estuary - RN

PALAVRAS-CHAVES:

Trace Elements, geochemical index, Potengi river estuary

PÁGINAS: 28
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
ESPECIALIDADE: Geoquímica
RESUMO:

Estuaries are complex environments and present constant evolution processes, including the influences of sea, rivers and anthropic activities. In these regions, the abundance, distribution and speciation of chemical elements (metals, metalloids, non-metals, etc.) in the sediments can be affected by hydrodynamic processes related to variations in lithology, topography, vegetation, rainfall, river flows, input of tidal currents during flood and ebb cycles. The main objective of this research is to understand the processes that control the variability of the chemical elements in cores along the Potengi river estuary, including the possible contribution of anthropogenic loads. Statistical tools, such as the coefficient of variation, were used for duplicate samples and for analytical results obtained in different grading classes (total fraction and fraction less than 0.063 mm). The results were also compared to toxicological limits established by the National Oceanic and Atmospheric Administration (NOAA) in order to diagnose the quality of the sediments and their influence on the estuarnie ecology. They were also correlated with the world average shales and sandstones, and applying specific methodologies it was possible to estimate the background of the studied estuarine region. The Geo-accumulation Index (Igeo) was also applied in order to have a diagnosis regarding the enrichment of trace elements for the analyzed sediments. A total of 13 elements (Al, As, Ba, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr and Zn) were evaluated along three samples distributed longitudinally in the Potengi River estuary, being one more upstream (CPOT A), one in the middle part (CPOT B) and one at the mouth of the estuary (CPOT C) and the preliminary results indicate anthropogenic action and geogenic enrichment for the area investigated. The evidence collected in the intermediate region of the estuary (CPOT B) has shown to be more worrying, mainly to the chromium element. The influence of the proximity from the urbanized area of the city of Natal, which discharges sanitary waste without previous treatment, associated to manufactured goods industries contributed to alarming levels of contamination in this sampling region. Other indexes of classification, such as Enrichment Factor (EF), Pollution Loading Index (PLI), Anthropogenic Factor (AF) and Degree of Contamination (DC) will be linked later, seeking further subsidies to understand the geochemical processes in the region. In addition, the data will also be compared with other estuaries that used similar methodologies in Brazil and in the World.

MEMBROS DA BANCA:
Presidente - 2042405 - MOAB PRAXEDES GOMES
Externo ao Programa - 347608 - GERMANO MELO JUNIOR
Externo ao Programa - 1298966 - RAQUEL FRANCO DE SOUZA