Estimativa de carga de fosfato na água e fósforo no sedimento na vertente marítima de Fortaleza, Ceará

Abstract

The load of pollutants dispersed in a hydrographic basin can be transported and released by urban drainage systems, representing a source of pollution for the receiving bodies. This process intensifies in large cities with high levels of waterproofing and diverse diffuse sources of contaminants. The load of these pollutants, due to the variability of precipitation events and inaccurate location of generators, makes measurement difficult. In this context, the present work aimed to apply a modeling tool to estimate and analyze the phosphate loads in the water and phosphorus in the sediment released by the urban drainage system of the Maritime Strand of Fortaleza, Ceará, through the application of a hydrological-model. hydraulic. Thus, the computational model PCSWMM was used to estimate the release flows of the drainage system. The load estimation methodology obtained average diffuse phosphate load in the water between 0.78g/day.ha and 74.23g/day.ha for the analyzed basins and average phosphorus loads in the sediment between 5kg/year and 92, 84kg/year. The correlation analyzes of the loads with average precipitation (mm/day) of the analyzed periods and the correlation of the phosphorus load in the sediment with the impermeable area (ha) of the analyzed sub-basins presented a model of estimation of the loads, with adjustment in a function power of order two (R2>0.65). The proposed methodology is capable of estimating phosphate and phosphorus loads in the drainage systems and can contribute to the qualitative management of the Drainage System of the Fortaleza Maritime Side. It is expected that this methodology can be applied in other cities with similar hydroenvironmental characteristics.