Electrocatalytic Degradation of Levofloxacin, a Typical Antibiotic in Hospital Wastewater

Construction of a Zero-gap Flow-Through Microfluidic Reactor with Porous RuO2 -IrO2 @Pt Anode for Electrocatalytic Oxidation of Antibiotics in Water

In this study, a zero-gap flow-through microfluidic reactor was constructed for the degradation of tetracycline and norfloxacin in water using a porous Ti/RuO2 -IrO2 @Pt electrode as the anode and porous titanium plate as the cathode. The operation parameters included electrolyte type, electrolyte concentration, current density, initial concentration of pollutants and pH, were investigated. The degradation efficiency and energy consumption were calculated and compared with traditional electrolyzer. In the zero-gap flow-through microfluidic reactor, 100 % of both tetracycline and norfloxacin can be decomposed in 15 min, and high mineralization rate were achieved under the optimized reaction condition. And the reaction was consistent with pseudo-first-order kinetics with k value of 0.492 cm-1 and 1.010 cm-1 , for tetracycline and norfloxacin, respectively. In addition, the energy consumption was 28.33 kWh ⋅ kg-1 TC and 8.36 kWh ⋅ kg-1 NOR, for tetracycline and norfloxacin, respectively, which was much lower than that of traditional electrolyzer. The LC-MS results showed that tetracycline underwent a series of demethylation, dehydration and deamination reactions, and the norfloxacin went through ring opening reaction, decarboxylation and hydroxylation reaction, and finally both produced CO2 and H2 O.

Insight into advanced oxidation processes for the degradation of fluoroquinolone antibiotics: Removal, mechanism, and influencing factors

The enrichment and transport of antibiotics in the environments pose many potential hazards to aquatic animals and humans, which has become one of the public health challenges worldwide. As a widely used class of antibiotics, fluoroquinolones (FQs) generally accumulated in the environments as traditional sewage treatment plants cannot completely remove them. Advanced oxidation processes (AOPs) have been shown to be a promising method for the abatement of antibiotic contamination. In this review, influencing factors and relevant mechanisms of FQs removal by various AOPs were summarized. Compared with other AOPs, photocatalytic ozone may be considered as a cost-effective method for degrading FQs. Finally, the benefits and application restrictions of AOPs were discussed, along with proposed research directions to provide new insights into the control of FQs pollutant via AOPs in practical applications.

Enhanced tetracycline removal using membrane-like air-cathode with high flux and anti-fouling performance in flow-through electro-filtration system

The membrane-like air-cathodes modified with different polyaniline were prepared using phase inversion method, which possessed dual functions of interception and electrochemical degradation, and showed good conductivity (15.9 ± 0.4 to 25.7 ± 0.5 mS cm^-1) and porosity (77.0 ± 0.1 to 87.8 ± 0.1%) compared to the unmodified control one (13.2 ± 0.5 mS cm^-1, and 63.1 ± 0.7%). At tetracycline 50 mg L^-1, the cathode with 25 wt% polyaniline exhibited the highest rejection rate and final removal (71.1% and 92.9%, 35.9% and 31.4% higher than the control), the highest water flux recovery (97.9%), and the lowest attenuation of porosity and conductivity. The modified cathode also showed an autocatalytic effect on H₂O₂, an obvious ^·OH peak appeared on the electron paramagnetic resonance curves. It also had good anti-fouling performance because it exhibited a high durability (the final removal was decreased by 4.0% after 15 cycles) with a long service life of 124 periods (372 h, 15.5 d). The tetracycline (0.5 mg L^-1) removal in the river background was near 100%, and the chemical oxygen demand removal was 91.9%, supporting that it was suitable for treating antibiotics in natural water without adding agents but only for electricity consumption.