Wetted-wall corona discharge induced degradation of sulfadiazine antibiotics in aqueous solution

BACKGROUND: Sulfadiazine, is a potent antibacterial agent belonging to the sulfonamide class of antibiotics and is widely used as veterinary and human medicine, has been detected in contaminated water and soils. A cylindrical wetted-wall corona discharge was applied for the removal of sulfadiazine. The target water was made to flow as a film over the surface of the electrode; the radicals generated at the gas-liquid interface discharge can efficiently reach the flowing-water film surface. RESULTS: Initial concentrations of 10 mg L-1 sulfadiazine can all be removed within 30 min under discharge conditions of 100 W. The degradation of sulfadiazine can be enhanced by the addition of hydrogen radical scavengers, but can be inhibited by adding hydroxyl radical scavengers. Both kinds of radical scavengers can increase the concentrations of H2O2. The wetted-wall corona discharge was ineffective in mineralization, but it can be enhanced by CCl4. Based on the results of LC-MS analysis, six intermediates were identified and the proposed evolutionary process was investigated. CONCLUSIONS: Wetted-wall corona discharge can effectively degrade sulfadiazine inaqueous solution. These results are helpful for exploring new efficient technology and the evolutionary mechanism for antibiotics treatment. (C) 2013 Society of Chemical Industry