Resumen
The removal of enoxacin (ENO), a broad-spectrum fluoroquinolone antibiotic, was firstly examined in a sulfate-reducing up-flow sludge bed (SRUSB) bioreactor over a long-term operation (366 days). Over 94% of the ENO was removed in the SRUSB bioreactor via adsorption and biodegradation at different initial ENO concentrations (i.e., 25?1000 µg/L). Based on the results of the batch tests, the sulfate-reducing sludge exhibited a high ENO adsorption capacity within a kd of 22.7?28.9 L/g-SS. The adsorption of ENO by the sulfate-reducing sludge was a spontaneous (?G° < 0 KJ/mol) and exothermic (?H° < 0 KJ/mol) process including physisorption and chemisorption (absolute value of ?H° = 51.882 KJ/mol). Moreover, ENO was effectively biodegraded by the sulfate-reducing sludge within specific rates of 2.5?161.3 µg/g-SS/d. The ENO biodegradation process in the sulfate-reducing sludge system was most accurately described by the first-order kinetic model. Collectively, our findings provide insight into the applicability of a sulfate-reducing sludge system for ENO-contaminated wastewater treatment.