Experimental Study On Chemical Migration In Groundwater Environment

With the rapid development of industrialization,chemical accidents occur frequently in chemical plants due to flaws in production safety,which poses a threat to the ecological environment.Contaminants may enter groundwater after passing through the unsaturated zone of the soil,thereby indirectly endangering human survival and health.In this paper,the migration process of chemicals in soil and groundwater environment was simulated through experimental research,revealing the laws of chemical migration in saturated and unsaturated soils.In the study,the experimental and calculation methods for measuring parameters such as the permeability coefficient,dispersion coefficient and adsorption coefficient of soil were described.The parameters such as permeability coefficient,dispersion coefficient of sand,and adsorption coefficient of butanone in silty clay were determined.In the simulated saturated zone,the concentration distribution of the solute in the sand box at different times was determined by changing the flow rate of simulated groundwater,the injection method of pollutants,the location of the injection of pollutants,the solute,and the medium.The experimental results show that the regions with higher sodium chloride concentration will be strongly affected by gravity due to higher density,and the diffusion effect between different detection pores with larger concentration difference will be stronger,and the hydrodynamic dispersion effect of high water flow velocity is stronger than low water flow rate.These kinds of effects will play a leading role respectively due to different experimental conditions.The smaller particles and pores of silty clay will slow down the migration rate of solute.In the unsaturated zone,the sand with finer particles has higher water holding capacity and stronger capillary action,and the soluble solute is prone to capillary and diffusion phenomena.In unsaturated soil column experiments with 12 weeks observation in natural conditions,insoluble dimethyl disulfide can slow the rate of migration due to the increase of water content in the soil,and it is difficult to detect methamphetamine at a depth of 15cm.