Degradation Characteristics of Sulfamethoxypyridazine in Water by Ozonation and Photocatalysis

摘要

Pharmaceuticals and personal care products (PPCPs) have emerged as a major class of contarninants, given their widespread usage and known biological effects. Sulphonamides are synthetic antibacterial agents widely used in veterinary practice for the treatment of infections and to promote the growth of food-producing animals. Traditional sewage treatment procedures are unable to get rid of these compounds effectively. Advanced oxidation processes (AOPs) are a promising technology for treating wastewaters containing sulfamethoxypyridazine pharmaceuticals via O3 and UV/TiO2 process. This study performs batch experiments to determine the effects of operating parameters on the degradation efficiencies of sulfamethoxypyridazine. The degradation was studied by monitoring the intermediates employing high performance liquid chromatography (HPLC) separation coupled to an atmospheric pressure ionization mass spectrometry (API-MS) system operating under selected ion monitoring (SIM). Results show that complete removal of all sulfamethoxypyridazine was achieved within 80 min of ozonation at the concentration of O3 (3 ppm) at different pH runs. The ozonation of sulfamethoxypyridazine demonstrated the best degradation efficiency for runs at pH 8, followed by runs at pH 6 and pH 11. The ozonation imposed sulfamethoxypyridazine with a time dependence that appeared to follow pseudo first-order kinetics. The original concentration of sulfamethoxypyridazine almost completely degraded within 7 hr in UV/TiO2 at pH 6 runs. The reaction rates for the decomposition of sulfamethoxypyridazine in water are higher at pH 6 run than for runs at pH 3 and pH 11. Three organic intermediates appeared during the photocatalytic degradation of sulfamethoxypyridazine.