Effects of the hydrodynamics of Guamá river estuary on the dispersion of organic load in Tucunduba Igarapé, Belém, Pará (Brazil) State

Abstract

ABSTRACT The objective of this study was to evaluate the contribution of the organic load to Tucunduba Igarapé. The data were collected over 12 h for continuous analysis of physical variables, and every 3 h for physicochemical analysis. The cross-sectional profile and flow rate were measured using an accustic doppler current profile, and the load of organic matter was estimates using equations. Three distinct flow periods were verified, two of which were governed by the hydrodynamics of the Guamá River estuary and the other by unidirectional flow from Tucunduba Igarapé to the Guamá River estuary. The organic loads of biochemical oxygen demand (0,03 kg d-1 – 0,07 kg d-1) produced in Igarapé is greater than the contributions from the Guamá River estuary. The Guamá River estuary exerts a positive effect on the Igarapé by dispersing the produced organic loads and aiding its capacity for self-purification.