Highly efficient disinfection of antibiotic-resistant bacteria in water using a novel UV-LED/periodate combined process: mechanisms and performance evaluation

Abstract

Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have become persistent waterborne contaminants, posing serious environmental and public health concerns. Innovative and efficient disinfection technologies are urgently needed for eliminating these pollutants. Here, a novel advanced oxidation process (AOP) was developed by combining ultraviolet light-emitting diodes (UV-LEDs) at three wavelengths (265 nm, 280 nm, and 310 nm) with periodate (PI) to evaluate its performance in eliminating ARBs and intracellular ARGs. The UV-lED/PI process at 265 or 280 nm significantly enhanced bacterial inactivation, achieving >5-log reductions within 30 s and exceeding the performance of most previously reported AOPs. By contrast, the UV-LED 310 nm/PI process showed relatively low disinfection efficiency (<1.4-log reduction within 120 s). An obvious synergistic effect between UV-LEDs and PI was observed, resulting in lower energy consumption compared to UV-LED irradiation alone. Although natural water constituents such as humic acid, suspended solids, and bicarbonate exerted moderate inhibitory effects, the overall disinfection performance remained high. Radical quenching, SEM, FTIR spectroscopy, and potassium ion leakage analysis revealed that microbial inactivation was primarily driven by UV-LED irradiation and hydroxyl radicals (HO^•), which compromised cell membrane integrity and disrupted secondary protein structures. Furthermore, the UV-LED 265 nm/PI process achieved 65–80 % degradation of tetracycline antibiotics and effectively removed int1 and sul1 genes by 2.37-log and 2.18-log within 30 min, respectively. These findings demonstrate that the UV-LED/PI process is a highly efficient, energy-saving, and promising technology for controlling antibiotic-resistant contaminants in water treatment.