NAA application in the geochemical behavior study of lake sediments elements of a wastewater treatment plant

Neutron activation analysis have been employed to determine 24 elements in bottom sediments from one lake of the Wastewater Treatment Plant of Barueri, SP, aiming to verify a possible contamination of this lake due to the wastes produced in the plant. The results obtained were compared with the concentration determined in soil profile and in a sample of rock, in natura, representing the lithologies of the region. Analysis was used in dry and wet seasons. The analysis of the data did not show a significant variation in concentration levels during the different periods, except for As. The results obtained showed a homogeneous distribution of the elements all along the lake and indicate that only As, Cr and Zn can have their origin associated with the residues disposed around the lake. (author)