Contaminantes emergentes em coleções hídricas na região da grande João Pessoa - PB : avaliação da presença e eficiência de remoção nas estações de tratamento de água e esgotos

Abstract

The Emerging Contaminants (ECs) have become a relevant issue, particularly due to the increase in consumption and, consequently, the high production of these pollutants in contemporary society. These compounds can alter environmental characteristics and affect human health, even at low concentrations. The interest in studies related to the occurrence and effects in the environment is recent, and there is still a lack of data related to the occurrence of these contaminants in Brazil, especially in the state of Paraíba. Therefore, the quantitative determination of ECs in environmental matrices is of great importance as it enables the establishment of the true contamination scenario in the environment. In this context, this study aimed to assess the presence of ECs in water and sewage treatment plants in the water supply production area of Greater João Pessoa, state of Paraíba. Eleven compounds were investigated, including atrazine, 2,4-D, carbendazim, nimesulide, amoxicillin, sodium diclofenac, paracetamol, estrone, estradiol, 17-a-ethinylestradiol, and progesterone. Three collections were carried out throughout the year 2021 at the Gramame and Marés Water Treatment Plants (WTPs) and the Pedras de Fogo and Odilândia Sewage Treatment Plants (STPs). The target compounds were extracted from the aqueous phase by solid-phase extraction (SPE). Analytical determinations were performed by high-performance liquid chromatography. To evaluate the removal efficiencies of ECs in WTPs and STPs, removal efficiencies were calculated at the end of their respective treatments. Regarding water, the results revealed that, of the 11 compounds analyzed, only atrazine, 2,4-D, and carbendazim, contaminants belonging to the pesticide class, were identified in the Gramame WTP. Carbendazim was found in higher concentrations, ranging from 31.96 to 730.89 ng.L-1. Although detected, none of the ECs exceeded the limits set by MS Ordinance 888/2021, which establishes drinking water standards. In the Marés WTP, neither at the inlet nor at the outlet, any of the 11 contaminants were detected. Concerning sewage, of the 11 compounds analyzed, only 2,4-D and carbendazim were detected in both STPs. The other compounds were not detected. These results show that both water destined for public supply in Greater João Pessoa and the effluents are free from most of the ECs investigated in this study. Additionally, the removal efficiency of these compounds in WTPs and STPs, reaching up to 100%, as observed in the case of carbendazim in the Gramame WTP and Odilândia STP, and 2,4-D in both studied STPs, contributes to maintaining low levels. Therefore, this research provides valuable information regarding the presence and quantification of ECs in surface water collections, as well as in the water supply of Greater João Pessoa, contributing to understanding the contamination scenario in the region and emphasizing the ongoing importance of environmental monitoring to ensure the quality of water resources.