Removal of Sulfadiazine from Aqueous Solution by Potassium Ferrate

The aqueous reaction of potassium ferrate with sulfadiazine was investigated for evaluating the effects of ferrate dosage and pH value on the removal of sulfadiazine and analyzing the mechanism for oxidation of sulfadiazine by ferrate using LC-HESI-MS-MS.The results showed that sulfadiazine could be removed by ferrate efficiently.At a pH value of 7.0,86.2% of 0.02 mmol·L-1 sulfadiazine was removed after 10 min oxidation by dosing 0.100 0 mmol·L-1 potassium ferrate.However,less than 10% of TOC reduction was achieved in spite of quick conversion of sulfadiazine.The sulfadiazine removal efficiency and reaction rate were increased with the increasing dose of ferrate.The pH value of the solution had a great influence on the oxidation of sulfadiazine and the reaction performed well in neutral and weak acid condition.The by-products of sulfadiazine oxidation by ferrate were analyzed by LC-HESI-MS-MS and the results suggested that a majority of sulfadiazine was not complete mineralized,but transformed into large-molecule products,which was in agreement with the results of TOC.