甲硝唑自然光降解研究

Photodegradation of metronidazole under solar irradiation

药物与个人护理品(PPCPs)是一类近期引起普遍关注的环境"新型"微污染物.PPCPs的大量使用和排放造成环境中的持久性存在.光化学降解是水环境中PPCPs微污染物的重要消减途径.本文中以武汉地区夏秋太阳光为光源,研究甲硝唑的自然光降解行为.考察不同因素,即水质、pH、常见离子、初始浓度对甲硝唑光降解的影响,同时以紫外光源作对照.实验结果表明,甲硝唑在太阳光下迅速直接光降解;甲硝唑的初始浓度越大,光降解速度越慢;光源的强度越大,且波长越接近于目标物的最大吸收波长时,降解速度越快.

Pharmaceuticals and personal care products(PPCPs)had received much attention recently.Due to wide use of pharmaceuticals,many PPCPs were considered to be persistent in the environment.Photodegradation of pharmaceuticals caused by sun irradiation may be of major signi ficance in the natural elimination process.The fate of metronidazole in surface water under sunlight(Wuhan,summer)irradiation was investigated.The effects of different parameters such as pH,initial concentration of substrate,photosource,and the effects of bicarbonate ions,nitrate ions and Fe(Ⅲ) on photodegradation of metronidazole were studied.The results indicated that metronidazole should undergo fast direct photolysis under sunlight irradiation,and the photodegradation rate of metronidazole decreased obviously as the initial concentration increased,and a slower removal of metronidazole was observed under photosource with lower intensity.