RESUMEN
The objective of this work was to develop a method to calculate the water quality index (WQI) using chemometric methods. The study was carried out at the Curuá-Una hydroelectric power plant in the state of Pará in the Brazilian Amazon. Eight collection stations in four periods (winter, intermediate I, summer, and intermediate II) and 29 parameters were selected. Multivariate analysis was applied to the results to verify the quality of the data and to select the most sensitive variables to be used as indicators for the WQI calculation. The 10 parameters selected were E h, dissolved oxygen, total dissolved solids, chlorophyll a, phosphate, Ba, Ca, Fe, Na, and Sn. The WQI proposed herein was effective in the classification of water quality for the periods analyzed.
RESUMEN
Esta pesquisa foi desenvolvida na Plataforma Continental Amazônica (PCA) no trecho compreendido entre os cabos Orange (AP) e Maguari (PA), para determinar os teores de Zn, Co e Ni nos sedimentos superficiais, identificando o papel dos sedimentos como fonte ou reserva de elementos-traço. A concentração dos elementos metálicos apresentou a seguinte associação: Zn > Ni > Co. Os sedimentos localizados na PCA podem ser considerados como sítio de ocorrência natural dos elementos metálicos, não havendo influência de fontes poluidoras na liberação destes para o sistema.
Determination of trace elements (Zn, Co and Ni) in sediments at the Amazon Continental Shelf on influence of the Amazon River discharge This research was developed at Amazon Continental Shelf (ACS) between the Orange Cape (Amapá State) and the Maguari Cape (Pará State), to determine the levels of zinc, cobalt and nickel in the superficial sediments identifying its inputs and outputs. The rate of these metallic elements in the sediments decreases following Zn> Ni> Co. The concentrations of total metals in the surface sediments range from Zn = 52.8 159.5; Ni = 21.7 47.4 and Co = 14.3 48.8 (mg.kg-1). The levels of trace elements observed in the sediments at ACS are of natural occurrence. Pollution sources of metallic elements were not observed.