Degradation Of Sulfadiazine （SD） In Aqueous Solution Using Ultrasound Technique And Gamma Irradiation (⁶⁰Co)

Sulfadiazine (SD) is extensively used as raw materials in the manufacture of synthetic dyes and pharmaceutical products. The presence of SD in aquatic environment will pose significant human health and ecological risks because of its high toxicity and stability. Ultrasonic technology and gamma irradiation are two advanced oxidation process believed to be effective for aqueous contaminants degradation. This thesis was conducted to investigate the degradation of SD from aqueous solution using ultrasonic irradiation and gamma irradiation. The effects of initial concentration of aqueous SD, solution pH, hydrogen peroxide (H2O2) concentration and the addition of Fenton solution (Fe2+/H2O2) as well as ultrasonic intensity and or absorbed dose on SD degradation were discussed. The results are summarized as follows:During ultrasonic irradiation degradation efficiency of SD was enhanced with increasing ultrasonic intensity as well as in acidic solution pH or lower initial concentrations of SD. Moreover, the addition of H2O2 and Fe2+/H2O2 to aqueous SD solution is benefit for degradation of SD and the ultrasonic degradation efficiency was highlighted with higher concentrations of H2O2 and or Fe2+/H2O2 under the experimental conditions.On the other hand, gamma irradiation-induced removal of SD was found to be very feasible and effective in degradation of aqueous SD solution under my experimental conditions. A high-absorbed dose, low initial concentrations level of SD, an acidic media or low solution pH and addition of H2O2 and or Fe2+/H2O2 (Fenton solution) all enhanced, favored and also facilitated SD removal during gamma irradiation, which is similar to the ultrasonic irradiation.However, the degradation efficiency of gamma irradiation is higher than that of ultrasonic irradiation though the two processes are both mainly ascribed by (·OH) hydroxyl radical induced oxidation. Additionally, the main intermediates resulting from SD induced-gamma radiation were identified by Liquid Chromatography - Mass Spectrometry (LC-MS).