Photoelectrocatalytic coupling system synergistically removal of antibiotics and antibiotic resistant bacteria from aquatic environment

Antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are ubiquitous in the reclaimed water, posing a potential threat to human and ecological health. Nowadays, the reuse technology of reclaimed water has been widely concerned, but the removal of antibiotics, ARB and ARGs in reclaimed water has not been sufficiently studied. This study used TiO2 nanotube arrays (TNTs) decorated with Ag/SnO2-Sb nanoparticles (TNTs-Ag/SnO2-Sb) as the anode and Ti-Pd/SnO2-Sb as the cathode to construct an efficient photoelectrocatalytic (PEC) system. In this system, 99.9% of ARB was inactivated in 20 min, meanwhile, ARGs was removed within 30 min, and antibiotics were almost completely degraded within 1 h. Furthermore, the effects of system parameters on the removals of antibiotics, ARB and ARGs were also studied. The redox performance of the system was verified by adding persulfate. Escherichia coli, as a representative microorganism in aquatic environments, was used to evaluate the ecotoxicity of PEC treated chloramphenicol (CAP) solution. The ecotoxicity of CAP solution was significantly reduced after being treated by PEC. In addition, transformation intermediates of CAP were identified using liquid chromatography-tandems mass spectrometry (LC-MS/MS) and the possible degradation pathways were proposed. This study could provide a potential alternative method for controlling antibiotic resistance and protecting the quality of reclaimed water.

Automated summary

This study constructed an efficient photoelectrocatalytic system using TiO2 nanotube arrays decorated with Ag/SnO2-Sb nanoparticles as the anode and Ti-Pd/SnO2-Sb as the cathode. The system showed high removal efficiency of antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in reclaimed water, while also reducing the ecotoxicity of chloramphenicol (CAP) solution. The study provides a potential alternative method for controlling antibiotic resistance and protecting the quality of reclaimed water.