Numerical Simulation Of Groundwater Pollution In A Refinery In Yunnan

Yunnan refinery has complex geological conditions.There is a good connection between karst channel and fissure.The factory has the product tank farm,the intermediate raw material tank farm and the finished product irrigation area of the aviation coal products.Store a large number of oil raw materials.These constitute the pollution sources of groundwater environment.An oil spill would have an incalculable impact on the groundwater environment.In order to predict the impact of oil leakage on the groundwater in refinery.How to put forward effective control and treatment measures after pollution.This paper deals with the study of groundwater by solute transport simulation.In this study,hydrogeological investigation was conducted to obtain the initial groundwater level.The hydrogeological tests were carried out.Including Unicom test,seepage test,pumping test.Pumping test method to obtain hydrogeological parameters of groundwater.The initial groundwater level of groundwater is interpolated by the natural critical difference method to obtain the initial groundwater flow field.The error analysis of the flow field obtained after the operation of the MODFLOW module in GMS shows that the correlation between the initial water level and the measured water level is 95%.Then the relevant parameters are adjusted by using the combined pumping test data.The difference between the model and the actual model is small,the error is in line with the national standard,and can better reflect the characteristics of the groundwater system in the study area.By using the finite difference method to establish the mathematical model of groundwater and solute transport simulation by MT3 DMS MODFLOW module in GMS,the implementation of the prevention measures by using the forecast conclusion to guide the plant,and put forward relevant measures.The main research results are as follows:?1?The lithologic characteristics of the study area was complex,mainly composed of clay,dolomite,limestone and fine sandstone.Quaternary differences,through experiment,the vadose zone vertical permeability coefficient between 1.16 ×10^-6cm/s to 2.65×10^-3 cm/s;the underground water is divided into two layers,the type of underground water for diving the Eastern groundwater types of artesian water,groundwater runoff from the South and northwest overall.?2?Under abnormal condition,by running water flow model and MT3 DMS model shows that within 30 days,the pollution area was 313400m²;360 days,water wells at the pollution area was 1624000m²;3000 days,the pollutants will be migrated to the downstream village,a small stone bridge,QinglongShao,the impact range of up to 7720500m².The result shows that the pollutants leak into the groundwater,with the leakage point as the center is approximately oval continues to spread around,but also spread to the downstream of the hydraulic gradient of groundwater,and the pollutants at the same time along the flow direction perpendicular to the flow direction of the diffusion distance is greater than the diffusion distance.?3?Once the oil leakage accident occurs,it is the best attitude to take emergency measures to control and put forward effective solutions.On the one hand,the anti pollution performance of the aeration zone should be strengthened,and the study on the treatment of the contaminated soil has been proposed.On the other hand,the oil leakage through the vadose zone into the groundwater,it is recommended to change the groundwater flow patterns through the hydraulic control method to control the pollution source and then through the extraction process for extraction.On YJ01,YJ02 and YJ03 at the same time pumping simulation through the flow simulation,when the single well pumping capacity of 250m³/d formed a funnel,single well pumping capacity at 400m³/d is better,and has little effect on the downstream flow,can effectively prevent the further spread of pollutants to the downstream.Through the investigation of groundwater recharge runoff discharge to understand the movement of groundwater,and through the establishment of a groundwater flow model and water quality model of pollutants pollution and pollution range forecast,treatment measures of seepage control measures by using the forecast results to guide the plant and put forward after the accident,has reached the purpose of the study.