Avaliação do desempenho do ozônio na remoção de bisfenol-A : um estudo de caso na ETE UNISINOS– CAMPUS SÃO LEOPOLDO/RS

Abstract

In addition to the contaminants traditionally evaluated in sanitary sewers, such as BOD, COD, nitrogen, phosphorus, pH, color, etc., there is great concern about pollutants found in low concentrations, in µg/L or ng/L, that are not yet covered by Brazilian legislation. In this case, these are known as micropollutants or emerging contaminants (EC). Examples of micropollutants include pharmaceuticals, pesticides, endocrine disruptors (ED), hormones, personal care products, cleaning products, among others. Studies addressing these pollutants show that there is an accumulation and increase in concentrations in water resources, since conventional Effluent Treatment Plants (ETPs) do not have the capacity to remove them. Ozone is an effective disinfectant for application in wastewater and for disinfection of drinking water. It is efficient for the removal of a wide range of organic and inorganic compounds. In addition, it meets the requirements for reducing energy usage and reducing the use of chemicals in treatment systems, therefore, this study sought to evaluate the performance of ozone in the removal of Bisphenol-A at the Sewage Treatment Plant (STP) of the University of Vale do Rio dos Sinos (Unisinos) - Campus São Leopoldo/RS. This research identified notable variations in the presence of Bisphenol-A, ranging from 576.93 ng L-1 to 9176.48 ng -1. The evaluation of Bisphenol-A removal efficiency in biological treatment proved to be inefficient, as did the result of ozone-based removal analysis, which was also ineffective. Finally, statistical tests were conducted to assess the correlation between Bisphenol-A, COD, and pH; the tests suggest that there is no measurable linear relationship between these variables. The limitation of effectiveness of a conventional Sewage Treatment Plant in the removal of the investigated micropollutant was evident. It is crucial to emphasize that the results presented in this dissertation serve as a relevant warning regarding the presence of Bisphenol-A in domestic sewage, highlighting the complexity associated with its removal.