异丙草胺光解体系中溶解氧的增强效应

研究了异丙草胺光解过程中溶解氧的协同效应,在不同初始浓度溶解氧存在时异丙草胺在水中的光解规律.随着溶解氧初始浓度的增加,光解速率和效率均有提高,其中最高和最低光解效率相差30%.初始溶解氧浓度达到7.5mg/L后,光解速率和效率出现了平台效应,并且随着溶解氧浓度增加而有所下降.伴随异丙草胺的光解,溶解氧也有消耗,可以推测溶解氧也参与了光反应.通过对降解产物的分析,发现含高浓度溶解氧和缺氧条件下的光解产物基本一致,但部分光解产物生成量不同.通过光解体系做自旋捕捉实验,推测可能是通过单线态氧¹O₂机制进行光氧化.

Synergy Effect of Dissolved Oxygen in Photodegradation of Propisochlor in Aqueous Solution

The synergetic effect of dissolved oxygen (DO) in the photodegradation of propisochlor aqueous solution was investigated in the presence of UV. With the increase of dissolved oxygen concentration, from 0 to 7.5mg/L, photodegradation of propisochlor was accelerated. After the concentration of 7.5 mg/L, the rate and efficiency of photodegradation stopped increasing and began to decrease when the concentration became higher. During the photolysis process, dissolved oxygen was consumed. It suggested that the oxygen took an active part in the photolysis. It was found by analysis that the pohtolysis products under different dissolved oxygen concentrations were almost the same, but the production of several products was different. Singlet oxygen (¹O₂) as the resonance intermediate in the photolysis systems was confirmed by electron spin resonance spin trapping experiments.