Numerical Simulation Of Biogas Slurry Seepage And Diffusion In Soil

Biogas slurry can improve soil environmental effects,improve the quality of agricultural products and inhibit diseases and pests.However,there are certain potential risks in the use of biogas slurry.If the biogas slurry is applied excessively,the nitrogen,phosphorus and other elements in the biogas slurry will diffuse to the deep soil and even endanger the safety of groundwater.Therefore,the study on the seepage and diffusion law of biogas slurry in soil is of great significance to guide the return of biogas slurry to the field and prevent groundwater pollution.Based on the in-depth investigation of the current situation at home and abroad,this paper has done the following work:Carry out numerical simulation research on the diffusion law of biogas slurry in soil.The effects of biogas slurry irrigation flow,soil porosity,biogas slurry properties and particulate matter on the diffusion law of biogas slurry in soil were studied by two-dimensional numerical simulation.The results show that the biogas slurry flows into the soil from above,and the diffusion range of biogas slurry gradually increases with the increase of irrigation time;The greater the irrigation flow,the faster the biogas slurry diffusion;The diffusion range of biogas slurry is also related to the porosity of soil.The smaller the porosity is,the larger the diffusion range is;The density and viscosity of biogas slurry have no significant effect on the diffusion range of biogas slurry in soil;Biogas slurry particles will concentrate in the middle and upper part of the soil and block the pores.The numerical simulation of different biogas slurry irrigation methods was carried out.Through two-dimensional numerical simulation,the diffusion law of biogas slurry in soil under drip irrigation,underground buried pipe and hole irrigation was studied,and the effects of irrigation flow,buried pipe depth and pipe diameter on the results were analyzed.The results show that the diffusion range of biogas slurry increases with the increase of irrigation flow;Under drip irrigation,biogas slurry flows into the soil with an elliptical boundary,and the irrigation flow has a greater impact on the lateral diffusion;The buried depth and pipe diameter of underground pipe irrigation are the main factors affecting the diffusion of biogas slurry;Under the mode of hole irrigation,the depth of hole arrangement and hole size are the factors affecting the diffusion of biogas slurry.