Comparativo entre dados reais e sugeridos pela literatura de parâmetros de DBO para dimensionamento de estações de tratamento de esgoto nas regiões Sul e Nordeste do Brasil

Abstract

In search of guaranteeing the quality of life and health of the population, there is a demand for basic sanitation services, among which is the sanitary sewage system. The deficit in the area of collection, treatment and destination of domestic sewage in Brazil generates pollution of water bodies, affecting the quality of springs used for water supply in cities. The Sewage Treatment Plant (STP) aim to reduce the organic load, nutrients and pathogenic microorganisms of effluents destined for water bodies, reducing environmental hazards and pollution. For the proper dimensioning of an STP, it is necessary to use real data from the region in which it will be installed, however, due to several difficulties, notably the absence of real monitoring data, designers usually use values estimated in the literature, for the determination of the Biochemical oxygen demand (BOD) used in the sizing of STP. Seeking to assess whether the BOD parameters suggested by the literature used for the sizing of STS are representative for the South and Northeast regions of the country, in the present work we analyzed whether the adopted values of generation and removal of BOD are in line with the local reality. For that, stations were selected that have a project population between 100 and 200 thousand inhabitants of the chosen regions, resulting in 6 STP, 3 of which in the Northeast (ERQ Sul, STP do Baldo and STP Mangabeira) and 3 of the South (STP Padilha Sul, STP Insular and STP São João-Navegantes). Through data obtained from projection and operation of per capita water consumption, per capita sewage concentration, BOD concentration, BOD per capita load and BOD removal efficiency from stations, the values indicated in the literature were compared. The ERQ Sul station presented all the operating data with the greatest difference from those suggested by the literature and those stipulated in its project. Indicating the need to use of real data with analysis of the specific characteristics of the regions in which the stations will be operated.