Determinação de metais em amostras de água do mar da Baía da Babitonga, São Francisco do Sul - SC

Abstract

Babitonga Bay is an estuary that has a direct connection to the ocean. It is the largest navigable bay in Santa Catarina and has the port of São Francisco do Sul. The bay has potential plumes for the emission of contaminants, such as domestic sewage and industrial effluents. Considering the possible emission of potentially toxic chemica, a quantitative analysis of these species is necessary. In this context, the objective of this study was to determine the concentrations of lead, cadmium, copper and zinc in water samples from Babitonga Bay. The samples were collected from January, February and March 2014, at three different points in the bay. At each sampling point, the physical-chemical parameters were measured, indicating that the Bay has homogeneous characteristics within its range extension. It was developed a study to optimize the method for the metal determination involving a step of digestion in a photochemical reactor, in which the best digestion time was 9 min, and a study to determine the best instrumental conditions for metals determination by anodic stripping voltammetry. The voltammetric method was optimized, and the preconcentration time of 300s was sufficient to detect the analytes in the order of nmol L-1, presenting a linear working range between 0.1 and 8 · 10-7 mol L-1 for Cu and Pb, while for Zn and Cd it was 0.1 and 11 · 10-7 mol L-1. However due to a bug in the equipment, the samples analysis was not possible.