<p>Although the negative impact of contaminants of emerging concern (CECs) on the aquatic environment is a threat, their occurrence and removal in Brazilian wastewater treatment plants (WWTPs) remain largely unknown. This study monitored 225 CECs from multiple classes in two WWTPs applying different treatments and their efficiency in removing CECs was compared. Both WWTPs promoted a large reduction in CECs concentration, 81% and 97% of the total load for WWTP-A (aerated lagoon + sedimentation lagoon) and WWTP-B (activated sludge + sodium hypochlorite disinfection), respectively, with the latter also promoting 78% total organic carbon removal. The concentration of CECs ranged from 39 to 374,610&#xa0;ng L⁻¹ in the raw influent and from 2 to 36,416&#xa0;ng L⁻¹ in the effluent. The Principal Component Analysis score plot shows three agglomeration tendencies based on CECs concentration, with caffeine and metformin appearing isolated due to their high incidence. The hierarchical clustering dendrogram highlights similarities between influents (80%) but clear differences in effluents (50%), indicating distinct treatment efficiencies. Although residual concentrations were detected in the effluent, Environmental Risk Assessment indicated no significant risk to <i>fish, Daphnia magna, or green algae</i> if a dilution factor is considered. These findings highlight the higher efficiency of activated sludge–based systems and provide useful data on the occurrence and efficiency of different treatments toward removal of microcontaminants in urban WWTPs, supporting future monitoring and regulatory initiatives.</p> Graphical Abstract <p></p>