Effect of hydrogen peroxide on the simultaneous removal of veterinary antibiotics during aerobic liquid manure fertilization process

Veterinary antibiotics (VAs) in liquid manure-based fertilizers can be applied in the soil and cause an adverse effect on the soil ecosystem. This study evaluates the potential of hydrogen peroxide (H₂O₂) as an oxidant for the simultaneous removal of multiple VA groups during the aerobic swine liquid manure-based fertilization process. For this purpose, swine manure spiked with 10 mg L⁻¹ of target VAs was treated with 1.0% (v v⁻¹) H₂O₂ and then continuously aerated for 28 days in a laboratory-scale aerobic liquid fertilization reactor. The results indicate that 1.0% H₂O₂ effectively degrades penicillins, achieving removal rates exceeding 90% within 24 h. Tetracyclines and macrolides exhibited moderate susceptibility to H₂O₂ oxidation, after 28 days, achieving average removal rates exceeding 90% and 95%, respectively. In contrast, the sulfonamide group displayed the lowest removal efficiency, with an average removal rate of 70%. The study further reveals that the oxidative effect of H₂O₂ is the most pronounced in the early stages of fertilization, with degradation rates plateauing over time due to the gradual decomposition of H₂O₂ and interactions with organic matter in swine manure. Despite these limitations, H₂O₂ treatment did not significantly change the key chemical properties of the final liquid fertilizer, maintaining its fertilizer efficacy. These findings suggest that H₂O₂-based oxidation could be a cost-effective and an eco-friendly substitute for traditional methods for mitigating VA contamination in liquid manure fertilization systems. The results will help to better understand the effect of H₂O₂ on the reduction of VAs during the liquid fertilization process, which has the potential to make a significant contribution to mitigating threats to public health and the ecosystems associated with the application of liquid fertilizer in agricultural environments.