masterThesis
Capacidade de carga de fósforo de seis reservatórios da região semiárida brasileira
Fecha
2019-05-16Registro en:
OLIVEIRA, Carmem Júlia Sant'anna de. Capacidade de carga de fósforo de seis reservatórios da região semiárida brasileira. 2019. 33f. Dissertação (Mestrado em Engenharia Sanitária e Ambiental) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2019.
Autor
Oliveira, Carmem Júlia Sant'anna de
Resumen
The excessive enrichment of water bodies by nutrients and the increase in primary
production is a natural process that happens slowly, however, this process has occurred
in recent decades quickly, due to the increase in the external load of anthropogenic
nutrients. Since phosphorus is considered the limiting nutrient for phytoplankton growth
in lakes and reservoirs, the best way to control the effects of eutrophication is to control
the intake of this nutrient in the system. In order to reduce this entry, models have been
developed to calculate the maximum load of phosphorus, that is, their load capacity, but
most of the models used do not consider the temporal variation of the volume occurring
in reservoirs and lakes of semiarid regions. Therefore, this study estimated maximum
phosphorus loads for six reservoirs in the Brazilian semiarid region, from a mass balance
coupled to a water balance. This load is the maximum so that in 90% of the simulation
period the concentration of phosphorus in the reservoir was up to 30 mg/m³, which is the
limit established by law (CONAMA Resolution 357/05) for freshwater, in the remainder
of the time the concentration could exceed the limit established. Scenarios with three
vertical flow of phosphorus, four water demands, three initial concentrations and two
initial volumes were simulated. The results showed that the parameters adopted in the
simulations exerted a strong influence on the phosphorus loading capacity, with demand
and vertical flow being the most influential. The incorporation of the volume level
variation in the reservoirs, approached the simulations to the real situation of the region,
demonstrating the importance of considering the temporal variability of the volume to
obtain the reservoir load capacity of the semi-arid region.