Study On Pollutant Transport Laws Of Leachate In Soils

Using the soil column experiment, the transition and transform rule of garbage leachate in soil is studied. the Hydrus-1d software is applied to simulate the transform rule. All the soils in the experiments are taken from natural soil samples of outskirts, the basic physical properties for the selected soil samples are measured, such as bulk density, moisture content and particle size composition, etc. First,the one-dimensional hydrodynamic dispersion coefficient should be determined by tracer testing with chlorine ion as the tracer. Then the preparation leachate is used to leach the soil column and catch the leaching liquid at the bottom and determine the variational characteristics of the main pollution components including organic pollutants(CODcr), ammonia nitrogen and pH.In the software simulation part, the Hydrus-1d software is used to simulate the waste leachate migration process under the same conditions of experiment in laboratory. Compared the measured value in laboratory with the Hydrus-1d simulation of the main pollution components in the soil column, it is found that the simulation results have good consistency on the trend with laboratory measured values.Hydrus-1d l fit well on the garbage leachate migration in the soil system in theory regardless of the microbial degradation. Through sensitivity analysis of the the water pressure head and dispersion coefficient, we found the influence of changing pressure head on the water ammonia nitrogen concentration and COD at the bottom of the soil column is bigger than the vertical dispersion degree. The water pressure is decreased and vertical dispersion degree will reduce the soil strength of solute adsorption and the curve is more steep.The research achievements of this paper are the pollution control and repair of landfill soil,pollution control,management and evaluation of groundwater and to provide theoretical basis and technical support for reasonable selection of waste leachate treatment process.