High-frequency ultrasound processes as alternative methods for degrading meropenem antibiotic in water.

β-lactam, more specifically carbapenems, are antibiotics used as last resort pharmaceuticals to deal with infections. Despite the medical relevance, they are considered contaminants of emerging concern in water because of their recalcitrance to conventional systems in the municipal wastewater treatment plants. This work aimed to show alternative methods based on the use of high-frequency ultrasound (200-1000 kHz) at a laboratory scale to degrade meropenem (a representative carbapenem antibiotic) in water. The ability of the sonochemical method alone to eliminate meropenem was tested initially. Then, the improvements of degradation by the addition of ferrous iron, or Fe (II) plus UVA light (sono-Fenton, or sono-photo-Fenton methods) were assessed. Finally, the effect of the best ultrasound-based method on the removal of biological activity of meropenem was determined. • Three high-frequency ultrasound processes were applied to degrade meropenem in water. • Sono-photo-Fenton degraded 67% of imipenem at 60 min of treatment and decreased significantly HO accumulation. • Antimicrobial activity was removed after only 30 min of sono-photo-Fenton action.