Desempenho da ETE Uberabinha na remoção de fósforo total e nitrogênio amoniacal

Abstract

It is known that the lack of sanitation in Brazil is a reality of many cities and a wide problem that has been discussed by the authorities over the years. In this sense, the purpose of this study is to verify the efficiency of a domestic and industrial sewage treatment station in the city of Uberlandia (STS Uberabinha) concerning to the parameters total phosphorus and ammoniacal nitrogen, presenting the origin of these elements, their functions and the losses they offer to human health and to the environment. The analyzes of these parameters were performed in the own laboratory of the Municipal Department of Water and Sewage (DMAE), the city’s sanitation authority, which through the approval of the management, provided the data bank to the present study. In the effluent treatment carried out by DMAE, the nutrients are removed in the tertiary treatment of the STS, through the flotation method (DAF), which promotes the rise of the particles with the aid of the intake of chemical coagulant (Aluminum Polychloride) and air microbubbles, making them less dense than water, providing for their rapid removal at the top of the flotation unit. Using the mentioned method, the station had a much higher average removal efficiency for the phosphorus than for the nitrogen, 71.19% and 1.05%, respectively, showing sometimes a certain amount of nitrogen accumulation in the reactor effluent. In occurs that, even the STS Uberabinha presenting low efficiency in the removal of nitrogen, when analyzed sanitation rankings in large Brazilian cities, Uberlandia has always been at the top of the list. In view of this, it can be seen if on the one hand, the service offered by DMAE is somewhat satisfactory, compared to others Brazilian cities, on the other, the parameters taken into consideration in qualifying sanitation are questionable.