Evaluating emerging contaminant removal efficiency: analytical methodology and implications for water treatment in the southeastern Brazilian Reservoir

Endocrine-disrupting compounds and pharmaceutical actives are frequently found in contaminated surface waters, making their detection and quantification essential. This study focused on five contaminants: 17α-ethinylestradiol, 4-nonylphenol, bisphenol A, amoxicillin, and caffeine. Analytical methods using HPLC-DAD and LC-MS/MS were developed, demonstrating high selectivity and sensitivity, while minimizing matrix interferences and improving accuracy. To evaluate treatment efficiency, conventional processes were simulated through Jar Tests with samples from the Guarapiranga reservoir (São Paulo, Southeast Brazil). Results showed that the presence of organic matter adversely affects all treatment stages, reducing contaminant removal. Optimal conditions for removing conventional parameters such as color and turbidity differ from those required to eliminate micropollutants. These findings highlight the limitations of conventional treatment and emphasize the importance of continuous monitoring, as well as the development of complementary technologies capable of fully degrading potentially toxic contaminants.