阴-阳离子表面活性剂对啶虫脒在水溶液中光解的影响

Effects of SDBS and CTAB on photolysis of acetamiprid

研究了不同浓度的阴离子表面活性剂十二烷基苯磺酸钠(SDBS)和阳离子表面活性剂十六烷基三甲基溴化胺(CTAB)对啶虫脒在水溶液中光解的影响.结果表明,啶虫脒的光反应符合一级反应动力学规律,表面活性剂不直接参与啶虫脒的光反应.SDBS和CTAB对啶虫脒的光反应均有抑制作用,CTAB的抑制作用大于SDBS.当SDBS浓度低于400mg.L-1时,随着浓度的增加,SDBS的抑制作用有增强的趋势,在400mg.L-1时达到最强,而后,随着浓度的增加逐渐减弱.而CTAB的加入量为25mg.L-1时,即产生强烈的抑制作用,抑制率达到62.90%;加入量为50～150mg.L-1时,抑制作用趋于稳定,抑制率为80.36%～87.03%.

This paper focuses on the effects of cationic and anionic surfactants on the photolysis of acetamiprid in water. Cetyl trimethyl amine bromide （CTAB）and sodium dodecylbenzene sulfonate （SDBS） were used as the representative cationic and anionic surfactants. Acetamiprid was easily photolysed under mercury lamp irradiation, and the surfactants were not reactants in the degradation process. However they had important inhibiting effects on the photolysis of acetamiprid, and CTAB exhibited a greater inhibiting effect than SDBS. Under the experimental conditions, the photodegradation of acetamiprid was found to fit first-order kinetics. The results indicated that the inhibiting effect increased with the increase of SDBS concentration when it was below 400mg·L^-1, and then decreased with a further increase of SDBS concentration. When the concentration of CTAB was 25mg·L^-1, the inhibiting effect was strong up to 62.9% , and remained stable at 80.36% ～ 87.03% with CTAB concentrations in the range of 50 ～ 150mg·L^-1.