甲胺磷在水-气界面挥发动力学研究

研究了挥发时间、温度和气流量对农药甲胺磷在水-气界面挥发行为的影响.挥发量采用气相色谱法检测,利用保留值定性,以外标法定量.研究结果表明,温度升高、气流量增大,使甲胺磷挥发量增大较快,二者是影响甲胺磷挥发的主要因素;挥发时间在4 h之内对甲胺磷挥发量影响较大,4 h之后基本无影响.通过试验还研究了甲胺磷在水-气界面的挥发动力学.根据实验结果,建立了甲胺磷在水-气界面挥发的动力学模型,比较实验值与动力学模型计算值,二者基本吻合,相对误差≤5%,这表明该动力学模型可以用于预测甲胺磷在水-气界面的挥发行为.

Volatilization kinetics on volatilization of water-air interface of methamidophos

The paper presents the author's research on the influence of the volatilization time,temperature and air flux rate on volatilization behavior over the water-air interface of methamidophos solution.As is known,the residue methamidophos solution is extracted with methylene dichloride,whose concentration is measured with gas chromatography.The result of our experiments shows that the increase of temperature and air flux rate will accelerate the volatilization rate greatly.And temperature and air flux rate are also primary factors affecting the volatilization behavior.During a given period of time,for example,4 hours, volatilization rate of parathion-methyl is relatively high,while the experimental goes on.However,the volatilization rate will tend to zero when the testing air flux rate reaches 1.5 L/min and the concentration of the methamidophos solution is 100.0 mg/L.Thus,the paper has developed a volatilization kinetic model of methamidophos based on the aboe mentioned experimental results.Testing the experimental results,it can be found that the calculated data by the model is basically in conformity with the experimental data.Therefore,the model can be well used for forecasting the volatilization process of methamidophos of the water-air interface in a certain range of temperature and air flux rate.The relative error between the value of the test and forecasting value keeps under 5%.