Analysis And Prediction Of Chlorinated Hydrocarbons Pollution In Groundwater Of A Chemical Plant

Groundwater resources play an important role in China's total water resources.In the past 40 years of reform and opening up,with the taking of the national economy,the rapid development of a large number of industrial enterprises and urbanization has caused groundwater to be polluted to varying degrees,underground drinking water safety and people.Healthy living environments are increasingly threatened to varying degrees,and chlorinated hydrocarbons are one of the most common types of pollution in groundwater pollution.Most chlorinated hydrocarbons have been identified as carcinogenic by the International Agency for Research on Cancer(IARC)and are carcinogenic,teratogenic,mutagenic"triad"substances.Therefore,it is of practical significance to find out the degree of pollution of chlorinated hydrocarbons,the amount of pollution,and the movement of pollution.In this paper,a chemical plant sewage leak in a province in the north is taken as an example.The pollution values are detected by the monitoring wells in the surrounding and downstream,and then the pollution degree is calculated by the Nemero pollution index method,and the three-dimensional spatial distribution law is studied..The 3D geological model is constructed by using the borehole data and the previous hydrogeological data,and the pollution area and pollution amount of the characteristic pollutants are evaluated on the basis of the model.The migration of trichloroethylene was predicted using a GMS construction model.The conclusions reached are as follows:(1)The source survey is used to determine that the chemical plant is the only organic source of pollution in the study area.Through hydrogeological survey,it is determined that the flow of groundwater in the study area flows from the northeast to the southwest.The Quaternary water-bearing lithology is mainly sand,gravel layer,etc.;the bedrock fissure water is mainly distributed on the east and west sides of the survey area and under the concealed and Quaternary,with a thickness of 7-12m.(2)The main organic substances causing groundwater pollution are methylene chloride,chloroform,1-1-dichloroethylene,trichloroethylene,and tetrachloroethylene.The main cause of heavy groundwater pollution is trichloroethylene and Trichloromethane.From the plane analysis,the high-concentration contaminated area is mainly located in the chemical plant and between the chemical plant and the pond,and is oval.In the vertical phase,the concentration of each pollutant in the groundwater has the characteristics that the lower part is generally higher than the upper part.(3)According to the drilling data,the geological module of the Earth's three-dimensional visualization(EVS)software is used to construct a three-dimensional geological model of the key pollution area.Based on the geological model,the area of trichloroethylene exceeding the standard value(70ug/L)is 37204.61m~2,the volume of water is 80826.61 m~3,and the amount is8.9423kg.The amount of detected fouling(0.01?g/L)is 9.9365kg.The area of chloroform exceeding the standard(60?g/L)was 13443.9m~2,the volume of water was 19521.92 m~3,the amount was 2.06 kg,and the amount of detected fouling(0.01?g/L)was 2.77 kg.(4)The migration of trichloroethylene was simulated by using GMS to establish a water flow model and a pollutant transport model.In 2026,during the 10 years,trichloroethylene moved to the lower reaches of 515m and moved to the vicinity of the river,with a pollution area of 106,087m~2.In 2036,during the 20 years,trichloroethylene moved to the downstream by643m,with a pollution area of 151,551m~2.2048,32 During the year,trichloroethylene migrated875m downstream,with a pollution area of 172,747m~2.