Avaliação da remoção de fármacos e desreguladores endócrinos em sistemas simplificados de tratamento de esgoto(reatores UASB seguidos de pós-tratamento)

Abstract

This study evatuated the occurrence of nine micropollutants classified as pharmaceuticals or endocrine disrupting chemicals (EDC) in Brazilian sewage and assessed their removal in systems consisting of UASB reactors (Upflow Anaerobic Sludge Blanket) followed by the following simplified post-treatments: (i) two trickling filters (TF) filled with different bed medias, plastic and monge based; (ii) three polishing ponds operated in series; (iii) non- planted constructed wetland operated at subsurface flow filled with blast furnace slag. The target compounds were: 17-estradiol (E2); 17 -ethinylestradiol (EE2); nonylphenol (NP);bisphenol A (BPA); sulfamethoxazole (SMX); trimethoprim (TRI); bezafibrate (BZF); diclofenac (DCF); miconazole (MCZ). These micropollutants were extracted from raw and treated sewage samples using solid phase extraction (SPE) and then analyzed by highperformance liquid chromatography (HPLC) coupled to mass spectrometry hybrid ion trap - time of flight (LC-IT-TOF-MS). The occurrence of E2, EE2, BPA and MCZ in raw sewage was similar to that found in other studies, and E2, EE2 and MCZ were rareIy quantified. The antibiotics studied (SMX and TRI) and the other drugs (DCF and BZF) had a Iower incidence in relation to studies in other countries, indicating a Iower consumption of these drugs in Brazil. The UASB reactorsshowed inefficient removal of the EDC (NP and BPA) and some drugs studied (BZF and DCF). For the antibiotics studied, it was observed a relationship between hydraulic retention times and the removal efficiencies. The configuration UASB/polishing ponds showed the bestremoval efficiencies for the greatest number of micropollutants (four compounds were effectively removed, being inefficient in the removal of the EDC). The system UASB/non- planted constructed wetland displayed high removal efficiencies for two (SMX and TRI) of the six micropollutants studied and three others were partially removed (BPA,DCF and BZF),being inefficient in the removal of NP. UASB/T F systems showed varying removal efficiencies of micropollutants, depending on the bed media used. The plastic based material proved to be ineffective (none of the compounds were effectively removed), while the sponge based material displayed high removal efficiencies for two compounds (SMX and BZF),being the other compounds partially removed. In the case of DCF, no effect was observed in this system.