Ozone On The Removal Emciency Of Chlorothalonil In Soil

An experiment was conducted to study the effects of different temperature conditions of ozone pumped into the soil samples on the removal efficiency of chlorothalonil. This content of research is a new method of degradation pesticide. The research will produce a new environmental protection of degradation reagent, which is the important meaning in practical application. The main results are as follows:(1) When ozone was pumped into the soil at room temperature, the ozone could react directly with chlorothalonil in the soil, and ozone could promote removal reaction. Results showed that the best removal efficiency was obtained when400mg ozone was pumped into the soil. The removal rates for the soil samples with initial chlorothalonil contents of10,20,50mg/kg were67.3%,67.7%and68.4%respectively. At the early stage, as the frequency of ozone pumped into the soil samples increased from1to4times per day, the removal rate of chlorothalonil in the soil samples with initial chlorothalonil content of10mg/kg increased from25.1%to41.6%on the5th day. It was found that the removal rate of chlorothalonil could be effectively improved by increasing the mass of ozone or frequency of ozone under the same mass.(2) When ozone was pumped into the soil at high temperature, the ozone could react directly with chlorothalonil in the soil, and ozone could promote removal reaction. At the early stage, as the temperature increased from40to60centigrade, the removal rate of chlorothalonil in the soil samples with initial chlorothalonil content of10mg/kg increased from36.1%to57%on the5th day. This method could effective shorten the half-life of chorothalonil residues. At last stage, it was found that the removal rate of chlorothalonil could not be effectively improved under the high temperature and ozone.(3) When nitrogen was pumped into the soil at high temperature, the chorothalonil volatile rule:at the early stage, as the temperature increased from40to60centigrade, the volatile rate of chlorothalonil in the soil samples with initial chlorothalonil content of10mg/kg increased from14.1%to18.8%on the7th day. At last stage, it was found that the volatile rate of chlorothalonil could not be effectively volatilized under the high temperature and nitrogen. According to the experimental data, the best pure volatile rate was33.1%when the temperature was60centigrade.(4) When ozone was pumped into the greenhouse soil at high temperature, the practical verification showed that the removal rate of chlorothalonil could be effectively improved under the high temperature and ozone. The removal rate of chlorothalonil in the greenhouse soil with initial chlorothalonil content of10mg/kg reached81.9%on the10th day. The ozone and high temperature in the practical production was not only easy to operate, but also effectively reduce the economic cost. In the practical production, it suggests that the control of temperature can use double plastic film covered greenhouse. This method can improve the greenhouse temperature, and reduce the cost.