Degradation of antibiotics in water by non-thermal plasma treatment

The decomposition of three β-lactam antibiotics (amoxicillin, oxacillin and ampicillin) in aqueous solution was investigated using a dielectric barrier discharge (DBD) in coaxial configuration. Solutions of concentration 100 mg/L were made to flow as a film over the surface of the inner electrode of the plasma reactor, so the discharge was generated at the gas–liquid interface. The electrical discharge was operated in pulsed regime, at room temperature and atmospheric pressure, in oxygen. Amoxicillin was degraded after 10 min plasma treatment, while the other two antibiotics required about 30 min for decomposition. The evolution of the degradation process was continuously followed using liquid chromatography–mass spectrometry (LC–MS), total organic carbon (TOC) and chemical oxygen demand (COD) analyses.

► Oxidation of β-lactam antibiotics in water by a pulsed dielectric barrier discharge.
► The discharge was generated at the gas–liquid interface.
► Amoxicillin was completely removed after 10 min plasma treatment.
► Oxacillin required 30 min and ampicillin 20 min for total removal.
► The degradation products were identified and their temporal evolution was followed.