Research on the hydrolysis and soil degradation of hexaflumuron

The given paper is aimed to present our investigation and analysis of the influences of the degradation characteristic features of hexaflumuron in three different types of soils,the black soil in China Northeast,the red soil in Jiangxi and the loess,or the yellow-brown soil in Nanjing under the aerobic,anaerobic and aseptic conditions in the laboratory conditions. Our research has also been done aiming at the observation and analysis of the effects of different temperatures,different pH values and concentrations of copper ion( Cu2 +) and surfactant( sodium dodecyl sulfate,SDS) on the hydrolysis of hexaflumuron in the aqueous solutions. The results of our research have shown that,both the hydrolysis and degradation in the soils of hexaflumuron tend to follow the first-order kinetics law in all the above-mentioned cases. In addition,we have conducted the hydrolysis in the alkaline condition in the most prompt way,in comparison with those in the acid and neutral solutions. As a result,we have found the hydrolysis rate can be expected to get accelerated with the temperature rising,under the effect of temperature coefficient being 1. 11.The activation entropy has indicated a significantly negative correlation with the temperature,though no obvious correlation has been found between the activation energy and temperature in ourstudy. Nevertheless,in buffer solution of pH = 9 at 35 ℃,the hydrolysis rate of hexaflumuron has proved to be remarkably accelerated with the increase of Cu2 +concentration in the range of25-500 μg / L. Moreover,we have found that,the sodium dodecylsulphate turns out playing an inhibitory function while the restraining degree can be enhanced with the increase of the concentration of SDS in the range of 100-900 mg / L. Among the three types of soils,hexaflumuron can be made well observing the following sequence: the yellow-brown soil of Nanjing the black soil of northeast the red soil of Jiangxi,respectively. Thus,the results we have gained prove that the alkaline condition and higher amount of organic matter content in the soil really have significant effects on the degradation of hexaflumuron. Meanwhile,the clay content in the soil tends also contributes to the acceleration of the rate of soil degradation. To be more accurate,the order of rating under different processing conditions proves to be in the following descending order: anaerobic aerobic sterilization,respectively,which indicates that the process of hexaflumuron has been made degraded mainly by the biodegradation in the soils and the activities of anaerobe are likely to exert positive influence on the soil degradation of hexaflumuron.