| Profenofos is a moderately toxic pesticide commonly used in agriculture,and cyanidin-3-O-glucoside(C3G)is a flavonoid that exists widely in nature.This study aimed to clarify the photodegradation behavior of profenofos in water and the effect of C3 G on the photodegradation of profenofos.The thesis studies the photodegradation of profenofos in water by C3 G under the irradiation of high pressure mercury lamp,xenon lamp,ultraviolet lamp and sunlight;at the same time,the initial concentration,p H and coexisting anions of water environment under high pressure mercury lamp are studied.on the degradation of profenofos;compare the differences in photodegradation efficiency of profenofos in ultrapure water,pond water,paddy field water,and ditch water;through ESR spin capture technology,the photodegradation process is clarified The active oxide species in the phosphorescence degradation process was studied by ion chromatography;the change of bromide ion content during the phosphorescence degradation process of probenromium was determined;The main results of the experiment are summarized as follows:1.Under the illumination of high pressure mercury lamp,xenon lamp,ultraviolet lamp and sunlight,the photodegradation rate of profenofos in ultrapure water is high pressure mercury lamp > ultraviolet lamp > xenon lamp > sunlight.C3 G can significantly inhibit profenofos.For the photodegradation of aqueous solution,in the experimental concentration range,the greater the additive amount,the better the inhibition effect.The photodegradation rate of profenofos decreases with the increase of its initial concentration.2.Under the illumination of high-pressure mercury lamp,the photodegradation rate of profenofos increases with the increase of the p H value of the solution,and the photodegradation rate is significantly positively correlated with the p H of the solution.The molar ratio of profenofos is 1:5: In the experimental p H range of C3 G aqueous solution,with the increase of p H value,the inhibitory effect on the phosphorescence degradation of C3 G gradually weakened,and the degradation rate of C3 G gradually increased.3.Under the illumination of high-pressure mercury lamp,profenofos degrades the fastest in ultrapure water with a half-life of 8.97 min,and degrades the slowest in paddy field water with a half-life of 18.93 min.The degradation rates are ultrapure water > pond water >field >Ditch water > paddy field water.The inhibitory effect of C3 G on profenofos is also effective in the three natural waters.The soluble substances in the natural water cause the difference in the photolysis rate.The photolysis of phosphorus all played a certain inhibitory role.4.Under the illumination of high pressure mercury lamp,the bromide ion determination results showed that the degradation amount of profenofos and the increase of bromide ions were in a 1:1 relationship.PNDA capture experiments showed that the phosphorescence degradation of probromide produced hydroxyl radicals,and the content of hydroxyl radicals decreased sharply after the addition of C3 G.The ESR spectra showed that hydroxyl radicals,alkoxy radicals and singlet oxygen were generated during the degradation of profenofos aqueous solution under illumination,and the above free radicals were not generated in the C3G-added profenofos aqueous solution.LC-MS-MS detection results showed that the main photodegradation product of profenofos was O-(2-chlorophenyl)-O-ethyl-S-propylphosphorothioate,and the addition of C3 G did not change profenofos.According to the photodegradation pathway of phosphorus,C3 G can inhibit the photodegradation of O-(2-chlorophenyl)-O-ethyl-S-propyl-phosphorothioate,and the inhibition effect is stronger than that of profenofos. |
