The Study Of Tralkoxydim Hydrolysis And Photolysis Characteristics

Tralkoxydim is belong to cyclohexanedione herbicide, with high selectivity、high efficiency, low toxicity and other characteristics, could control the gramineous weeds of barley and wheat fields. The environmental chemistry behavior on tralkoxydim has not been reported. To this end, the degradation characteristics of tralkoxydim as the paper subject, the hydrolysis and photolysis of tralkoxydim has carried out a systematic study, the hydrolysis and photolysis regularity of tralkoxydim was clarified, it can provide scientific basis for the safety assessment of its environment. We carried out the study of tralkoxydom hydrolysis and photolysis, the the half-lives of tralkoxydim has been preliminary explored.This article studied the hydrolysis of tralkoxydim with different buffer solutions、temperature、water bodies、surfactants in solution and different concentrations of humid. The results are as follows:(1)In acidic(p H =4)、neutral(p H =7)、alkaline(p H =9) buffer solutions,the half-lives of tralkoxydim were:10.7 d、41.3 d and 25.8 d. The tralkoxydim in neutral conditions was relatively stable, the degradation in acidic conditions was more than alkaline conditions.(2)The half-lives of tralkoxydim under the temperature of 25、35、45℃ were: 37.5 d、17.2 d and 14.2 d. The half-lives of tralkoxydim were gradually shortened with temperatures rising, the hydrolysis rate was gradually increased.(3)The half-lives of tralkoxydim in distilled water、running water、yitong river and paddy water were: 24.2 d、25.1 d、16.7 d and 14.6 d.(4)The half-lives of tralkoxydim in solutions with SDBS、SDS、TBAHS、Span 80 were: 31.5 d、19.7 d、22.7 d and 14.6 d.(5)The half-lives of tralkoxydim in humic acid concentration of 0 mg·L-1、5 mg·L-1、10 mg·L-1 and 20 mg·L-1 were: 33.3 d、31.3 d、22.7 d and 16.0 d. Increase the concentration of humic acid solution helps to improve the rate of hydrolysis of tralkoxydim.This paper used the 300 W and 500 W mercy lamp as light source, study the photolysis of tralkoxydim in different buffer solutions、organic solutions、waterbodies、mental ions in solutions and different concentrations of NO3-. The results are as follows:(1)Use the 300 W and 500 W mercy lamp as light source, the half-lives of tralkoxydim in p H =4、7、9 buffer solutions were: 135.9 min、123.8 min and 65.4 min; 315.0 min、108.3 min and 71.4 min. The degradation of tralkoxydim in alkaline conditions was promoted and restrained in acidic conditions.(2)In five different organic solutions, use the 300 W and 500 W mercy lamp as light source, the degradation of tralkoxydim were:acetonitrile > n-hexane > ethyl acetate>methanol>acetone, the half-lives were: 6.6 min、7.1 min、39.6 min、44.1 min and 113.6 min; 49.5 min、63.0 min、77.0 min、115.5 min and 256.7 min. The degradation of tralkoxydim has nothing to do with a polar solvent.(3)Use the 300 W and 500 W mercy lamp as light source, the half-lives of tralkoxydim in solution with Fe3+、Mg2+、Cu2+、K+ were: 15.5 min、29.7 min、38.1 min and 28.3 min; 65.4 min、117.5 min、110.0 min and 103.4 min. Fe3+ had an obvious promoting effect to the photolysis of tralkoxydim.(4)Use the 300 W and 500 W mercy lamp as light source, the half-lives of tralkoxydim in paddy water、yitong river、running water and distilled water were: 1.0 h、1.4 h、1.7 h and 1.9 h; 4.2 h、5.7 h、9.3 h and 8.3 h.(5)Use the 300 W and 500 W mercy lamp as light source, add in the NO3- solution concentration with 0、0.5、5、50、500 mg·L-1,the half-lives of tralkoxydim were: 1.5 h、1.9 h、5.5 h、6.7 h and 10.8 h; 4.1 h、5.3 h、7.3 h、10.4 h and 18.0 h. The NO3-has inhibitory action to the degradation of tralkoxydim, and with increasing concentration of NO3-, the inhibitory action also increases.Conclusion the above results, under the same light source, the intensity of light source had a greater influence on the photolysis of tralkoxydim, with the light intensity enhancement,the degradation half-lives extension.