Quinolone antibiotics in sewage treatment plants with activated sludge treatment processes: A review on source, concentration and removal

According to the existing research results, this paper reviews the influent and effluent concentrations, migration and transformation, and influencing factors of quinolone antibiotics in sewage treatment plants (STPs) with activated sludge treatment processes. Animal breeding and slaughtering wastewater, pharmaceutical wastewater and medical and domestic sewage may be the main sources of quinolone antibiotics. The compounds and concentrations of quinolone antibiotics in influents and effluents around the world are quite different, which is generally due to the difference in social and environmental factors in different regions, and the different treatment processes and operating parameters adopted. The migration and transformation of quinolone antibiotics is usually the result of the synergistic effect of sludge adsorption, biodegradation and photolysis. Sludge adsorption based on electrostatic interaction, hydrophobic forces and other mechanisms is the dominant route to remove quinolone antibiotics, but it does not reduce the total amount of the target antibiotics. An appropriate selection of conditions and control of process variables are beneficial to improve the removal of quinolone antibiotics by biodegradation with co-metabolism. Sources control, treatment processes improvement, fate understanding and prediction, monitoring strategies and risks assessment are potential options for improving the elimination and controlling the pollution of quinolone antibiotics in the future.