Evaluation Of Coal Gangue Matrix Properties And Vegetative Effects Based On The Utilization Of Bacterial Residues

Coal gangue,a by-product of coal mine,has the characteristics of poor structure,low nutrient content,high heavy metal content such as Fe?Mn,strong oxidation property and high acidity of leachate,so that its stacking environment is not conducive to plant growth.As the waste raw material of edible fungi,bacteria residue is rich in many organic nutrients.The carbon compounds produced by oxygen-limiting cracking are similar to biochar and are solid wastes with high utilization value.The purpose of this study is to apply the bacteria residue and its carbonation to the coal gangue soil environment and evaluate its effect,so as to enhance the water retention performance of the coal gangue soil matrix,provide nutrients for the plant to grow stably on its surface and control the transfer and transformation of pollutants.Water retention test and leaching test were carried out by applying bacteria residue and bacteria residue carbides to different proportions of coal gangue-soil mixed matrix,and then pot experiment was carried out with perennial ryegrass.The following conclusions were obtained:(1)The effect of bacteria residue and bacteria residue carbonization on water retention properties and basic physical and chemical properties of coal gangue soil matrix was studied.At the time of mixing 2.5%and 2.5%residue carbides and coating 2 cm on the substrate surface,can increase the p H of pure coal gangue matrix by 39.6%,reduce the bulk density to 1.24,and increase the organic matter content by 57.7%,respectively.Bacterial residue-bacterial residue carbonization can effectively enhance coal gangue-soil matrix p H?reduce matrix redox potential,reduce matrix bulk density,increase organic matter and available nutrients such as nitrogen,phosphorus and potassium,Improve coal gangue-soil matrix water retention capacity;Can also effectively reduce the content of available Fe?Mn in coal gangue-soil matrix,To weaken the migration ability of pollutants from coal gangue soil matrix to the surrounding environment.(2)The migration of pollutants from pure gangue leaching solution was studied by bacterial residue and biochar in leaching test.Apply 2.5%bacteria residue and bacteria residue carbides to the pure coal gangue leaching column and place cm bacteria residue carbides below,The total Fe removal rate of coal gangue leaching solution is 99.9%,and the total Mn removal rate is 67%,and the removal rate of SO₄^2-reached 72.3%respectively.To effectively improve the pure coal gangue leaching solution p H?reduce the leaching solution EC?reduce the pollutant content in the leaching solution,The migration and transformation ability of pollutants in pure gangue matrix to the outside world is greatly reduced.(3)Effects of residue-slag carbides on heavy metal content such as ryegrass growth,gangue-soil matrix Fe?Mn and migration and transformation ability of leachate pollutants to the outside world were studied.Combined treatment of 2.5%bacteria residue and 2.5%bacteria residue with carbides can significantly improve the growth of ryegrass and increase its Fe?Mn absorption efficiency by 14.8%and147%,Absorption transfer coefficient Mn pure coal gangue is 2.12%,A reduction of 74%and 75%in the effective Fe?Mn of pure coal gangue matrix,and the removal rate Fe?Mn pure coal gangue leachate reached 72.3%and 62.3%respectively.The application of bacteria residue and bacteria residue carbonization can effectively promote the growth of ryegrass and enhance its ability to fix heavy metals,Reduce the ability of pollutant migration and transformation to the outside world.In addition,Also continuously improve the pot substrate p H?regulate the redox properties of the substrate,Improve matrix structure stability and nutrient content.