Otimização de processo eletrolítico para remoção do antibiótico ciprofloxacina em água residuária sintética

Ciprofloxacin (CIP), an antibiotic of the fluoroquinolone class, has low biodegradability and possible toxic environmental effects. Due to its extensive use, it is considered an emerging contaminant (EC) in environmental compartments such as water, sludge, and sewage that contribute to antimicrobial resistance. This work assessed the optimal conditions for removing CIP in synthetic wastewater using electrolytic treatment and a laboratory-scale reactor with aluminum electrodes. The experiments were carried out from reconstituted synthetic wastewater fortified with 10 mg L-1 of CIP. The operational parameters of the reactor, such as pH, voltage, and concentration of the supporting electrolyte (NaCl), were optimized based on the reduction of the CIP concentration through the complete factorial design 2³ followed by optimization by the response surface methodology employing central composite rotational design (CCRD) from the regression analysis of the quadratic model. The best operational condition obtained was pH = 7.6, voltage = 5.6 V, and [NaCl] = 0.6 g L-1. In the validation tests, the removal achieved over 120 min was 78%, with equilibrium established after 80 min. It is suggested that, in addition to removing CIP by electrocoagulation mechanisms, there is also degradation by the electro-oxidation mechanism, promoted by oxidizing species produced from components of the reaction medium. The applied electrolytic process proved favorable and promising for removing CIP in synthetic wastewater.