Numerical Simulation Of Groundwater Pollution In An Alumiina Technical Transformation Project

In the arid or semi-arid regions of the north,due to limited surface water resources,groundwater becomes the main source of water for production and domestic use.With the rapid increase of population,the improvement of people's living standards and the rapid increase of industrial production capacity,the demand for water is increasing,the amount of groundwater extraction is increasing,the total amount of groundwater is decreasing continuously,and because of domestic garbage,sewage,industrial waste and wastewater.The random discharge makes the groundwater pollution caused by the pollutants entering the groundwater,and the groundwater quality is declining.And because the groundwater regeneration and self-purification ability is extremely poor,it is difficult to reverse the groundwater once it is contaminated.Xiaoyi City,Shanxi Province is one of the most developed county-level cities in Shanxi Province.There are many chemical industries in the county.The chemical industry will produce industrial wastes and waste liquids in the production process.Under abnormal conditions,these The production waste liquid penetrates the aeration belt into the groundwater and causes irreversible damage to the groundwater environment.Therefore,it is of theoretical and practical significance to study the migration law of pollutants in groundwater.This paper takes an alumina technical transformation project in XiaoyiCity as an example to study the production process.(1)The industrial wastewater collection tank in the plant area is in an abnormal condition(the crack occurs in the bottom plate),and the industrial wastewater passes through the aerated zone to enter the diving.The migration law after the aquifer;(2)The migration law of the red mud temporary storage yard in the plant area under the action of rainwater scouring and leaching,the pollutants pass through the aerated zone and enter the aquifer.In order to study the extent and speed of pollutant migration and the degree of impact on groundwater,the following work has been done:I.Collecting a large amount of hydrogeological data,conducting a survey of field environmental hydrogeology,and obtaining a study area through pumping test and water seepage test.Various hydrogeological parameters;II.Using the combined model of fuzzy matter element and projection pursuit,MATLAB should be used to evaluate the water quality status of the water quality monitoring wells in the survey area during the dry and wet periods;III.Using Visual Modflow software The migration laws and migration results of pollutants entering the aquifer at different times are predicted.The results show that the hydrogeological parameters obtained by the identification of the model are not much different from the calculated hydrogeological parameters;the water quality evaluation results obtained by the combined model are:the water quality grade of the wells in the plant is grade III(better)and the fertilizer The water quality grade of the plant water well is Grade II(good),and the water quality grades of other water quality monitoring wells are Grade I(excellent),indicating that the groundwater quality in the survey area is in good condition,and the water quality status in the dry and wet seasons The difference is not significant;the migration result of the pollutants entering the aquifer using the Visual Modflow software is:(1)Cracks appear in the bottom of the industrial wastewater collection tank.After 1 year,the maximum migration distance of F~-is 403.12m,and the affected area is 1.33hm~2.After 10 years,the maximum migration distance of F~-is 1676.24m,and the affected area is 66.57hm~2.It indicates that the industrial wastewater collection tank has cracks on the floor.After the pollutants enter the aquifer,the impact on the groundwater environment is large.Take targeted prevention measures;(2)Contaminants entering the aquifer under the action of rain erosion and forest filtration in the red mud temporary storage yard,1 year later,F~-The maximum migration distance is 749.83m,and the affected area is 46.01hm~2.After 10 years,the maximum migration distance of F~-is 3855.49m,and the affected area is427.08hm~2.It indicates that the red mud temporary storage yard of this project is under the action of rain erosion and forest filtration.After entering the aquifer,the impact on the groundwater environment is relatively large,and targeted prevention measures should be taken.