Effects of the hydrodynamics of Guam river estuary on the dispersion of organic load in Tucunduba Igarap, Belm, Par (Brazil) State

The objective of this study was to evaluate the contribution of the organic load to Tucunduba Igarape. 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 Guama River estuary and the other by unidirectional flow from Tucunduba Igarape to the Guama River estuary. The organic loads of biochemical oxygen demand (0,03 kg d-1 - 0,07 kg d-1) produced in Igarape is greater than the contributions from the Guama River estuary. The Guama River estuary exerts a positive effect on the Igarape by dispersing the produced organic loads and aiding its capacity for self-purification.