Effect of Acidic Oxidation of Swine Manure on Antibiotic-Resistant Bacterial Load, Unpleasant Odor, Veterinary Antibiotics, and Plant Nutrient Profile in the One-Health Perspective

Purpose. Advanced oxidation processes are known for their ability to remove organic pollutants, pharmaceuticals, and bacteria from wastewater, yielding outstanding results. However, these processes requires high energy input, costly equipment, and specialized operators.This study proposes a simple acidic oxidation method (H₂O₂ at pH 3 for 24 h) for in-situ treatment of pig effluent, offering a low-cost alternative for environmental management. Methods. The treatment was applied to effluents from three Italian farms, and its effectiveness was evaluated against: (i) bacterial load and amoxicillin-resistant bacteria by total viable count on selective media, (ii) nine commonly used veterinary antibiotics by LC-MS, and (iii) foul odor emissions by e-nose. Additionally, the fertilizer effect of treated effluents was examined using a maize pot experiment. Results. The treatment fully eliminated amoxicillin-resistant bacteria, reduced total bacterial load, and enhanced antibiotic degradation compared to natural dissipation (-53% vs. -48% over 24 h). Odor emissions were reduced by 20–80%, depending on organic content. Fertilizing properties were preserved, with improved Cu, Fe, and S uptake in plants (+ 25 to + 32%). Conclusions. These results highlight a practical, effective method for treating pig sludge, reducing its environmental impact while maintaining agricultural value.