DESEMPENHO DE TECNOLOGIAS AVANÇADAS E COMBINADAS COM WETLAND CONSTRUÍDO PARA REMOÇÃO DE CONTAMINANTES EMERGENTES EM EFLUENTE DE ESTAÇÃO DE TRATAMENTO DE ESGOTO

Abstract

The presence of emerging contaminants, such as pharmaceuticals, in the environment represents a significant concern due to their widespread use and their continued discharge into the environment. Furthermore, conventional treatment in sewage treatment plants (ETEs) cannot eliminate them completely. As a result, drugs and also their metabolites can be detected in various environmental compartments. This demonstrates the need to explore and aggregate technologies to reduce or prevent the deposition of these compounds in the environment. In this sense, nature-based solutions combined with advanced technologies, such as advanced oxidative processes (AOPs), constitute a promising approach to promote water treatment and reuse, in addition to providing multiple benefits. Therefore, this study aimed to use advanced technologies in the presence of light (photo-Fenton, UV, UV/H2O2), absence of light (O3, O3/H2O2, Fenton) and solar radiation, whether or not integrated into wetlands built to remove the drugs ketoprofen and diclofenac added to post-treated anaerobic effluent by a UASB reactor of a sewage treatment plant. To optimize the experimental parameters, factorial and central composite experimental design were used. The efficiency of the processes was monitored by high performance liquid chromatography, total organic carbon, physicochemical parameters and ecotoxicity in Artemia sp. and Lactuca sativa. Among the advanced technologies used as isolated processes, photo-Fenton with UVA light showed the highest efficiency in the degradation of drugs (97.2 ± 1.65%). The constructed wetland system combined with solar photo-Fenton (WC + FFS) showed excellent performance in the removal of ketoprofen (>95%) in the two processes used (WC+FFS at pH 3.0 and WC+FFS at pH 6.0) however, WC + FFS at pH 6.0 was more advantageous, noting that Brazilian legislation allows the disposal of effluents with pH between 5 and 9, thus eliminating a treatment step. The combined system showed excellent performance in removing ecotoxicity, with a toxic unit below 0.4 for both bioindicators, indicating that the by-products generated from the treatment do not present toxicity. Aligning and studying technologies could be the way to arrive at ideal treatment

system models that are efficient to treat conventional and emerging pollutants. The photo- Fenton solar process and constructed wetlands are compatible and their combination results in an innovative and effective method for municipal wastewater treatment systems.