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

Abstract

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.