Demonstration of Investigation Method of an Organophosphorus Pesticide Contaminated Site in North China

In order to provide guidance for the remediation of contaminated sites, a production site of organophosphorus pesticides in North China was selected as the research object. The soil and groundwater of the selected polluted plots were sampled by the method of distribution and direct extrapolation respectively, and the relevant methods were used for detection and analysis. The detection indicators mainly included volatile organic compounds, semi-volatile organic compounds and pesticide indicators. The results showed that some pollutants in the polluted land exceeded the limit seriously, far higher than the limit. In soil, the maximum multiple of benzene is 490.63 times, the maximum multiple of chloroform is 3459.09 times, the maximum multiple of parathion is 507.89 times, and the maximum multiple of methyl phosphorus is 1946.15 times. In groundwater, the maximum multiple of benzene is 220.83 times, the maximum multiple of dichloromethane is 1374 times, the maximum multiple of chloroform is 1853.33 times, and the maximum multiple of methyl phosphorus is 806.67 times. Sampling of soil and groundwater in contaminated sites by the method of distribution and direct pushing is superior to similar methods in four aspects: avoiding secondary pollution, ensuring the accuracy of data, ensuring the universality of data and reducing cost. However, due to the long history of the contaminated land and the volatile nature of most of the pollutants, there is still a need to improve the efficiency of avoiding secondary pollution and identifying pollutants.