Degradation Mechanism of Aqueous Sulfamerazine by AOPs of O3 and UV/TiO2

Advanced Oxidation Processes (AOPs) is a promising treatment technology for eliminating trace micropollutants, in the treatment of wastewaters containing sulfamerazine (one of pharmaceuticals) using O3 and UV/TiO2 process, respectively. The degradation was studied by monitoring the intermediates employing high performance liquid chromatography (HPLC) separation coupled with an atmospheric pressure ionization mass spectrometry (API-MS) system operated under selected ion monitoring (SIM). The results indicate that the original sulfamerazine almost was degraded within 90 min under the concentration of ozone 3 mg/L at different pH runs. The ozonation of sulfamerazine demonstrated the best degradation efficiency for runs at pH 8 than for runs at pH 6 and pH 11, respectively, under the concentration of ozone 1 or 3 mg/L. The original sulfamerazine was completely degraded within irradiation time of 5 hr at pH 6 runs in the concentration of O2-sparged 30 mg/L during the photocatalytic process. The rate constants are 0.086, 0.08, 0.04, and 0.027 hr-1 at the concentration of sulfamerazine 14.22, 21.33, 35.55, and 42.66 μM, respectively. Two intermediates were observed during the photocatalytic degradation of sulfamerazine.