Synchronous removal of pharmaceutical contaminants and inactivation of pathogenic microorganisms in real hospital wastewater by electro-peroxone process

Herein, a highly efficient electro-peroxone (E-peroxone) process with graphite felt as ozone diffusion electrode (ODE) was developed for the synchronous removal of pharmaceutical contaminants and inactivation of pathogenic microorganisms in real hospital wastewater. Under optimal conditions, the total organic carbon (TOC) removal rate of real hospital wastewater could reach 93.9%. Importantly, 126 pharmaceutical compounds (antibiotics, antivirals, analgesics, antiepileptics, hormones, and others) were determined in hospital wastewater by using ultra performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). 110 pharmaceutical compounds could be efficiently degraded in E-peroxone system. Concurrently, the microbial community analysis through high-throughput sequencing showed that E-peroxone process exhibited an excellent disinfection effect in real hospital wastewater. Escherichia coli as a bacterial indicator could be completely inactivated in E-peroxone process.H2O2 and hydroxyl radical ((OH)-O-center dot) were found in E-peroxone system based on the results of chemical probe experiments and electron paramagnetic resonance (EPR) analysis. The in-situ generation of H2O2 from cathodic oxygen reduction in ODE can react with ozone to produce (OH)-O-center dot, and realize high efficiencies for the elimination of pharmaceutical and sterilization. This work established a green and effective way without extra addition of chemical reagents for high-efficiency treatment of real hospital wastewater.

Automated summary

In this study, a highly efficient E-peroxone process with graphite felt as ODE was developed for the simultaneous removal of pharmaceutical contaminants and inactivation of pathogenic microorganisms in real hospital wastewater. The TOC removal rate of real hospital wastewater could reach 93.9% under optimal conditions. Furthermore, 110 pharmaceutical compounds were efficiently degraded in the E-peroxone system, demonstrating its effectiveness in eliminating pharmaceuticals. The E-peroxone process also exhibited excellent disinfection effects and could completely inactivate Escherichia coli in the hospital wastewater.