Effect of Lolium perenne Growth on Mn and Cd Migration in Soils Around Electrolytic Manganese Residue Storage Yard and Its Remediation
The effects of ryegrass growth on the leaching and migration of Mn and Cd in the soil around the manganese slag yard and its remediation were discussed by collecting the soil with different pollution levels around the manganese slag yard and using ryegrass as the test plant for pot-leaching test.The re-sults showed that the migration of Mn and Cd to water was significantly reduced after planting ryegrass,and the dissolution of Mn and Cd in soil with different pollution levels was generally expressed as the aboveground part of ryegrass group.From the enrichment ability of ryegrass to heavy metals,the enrich-ment coefficients of Cd in roots were 0.788,0.739,0.547,0.691 and 0.316,respectively,which were higher than those of Mn in roots,indicating that ryegrass had better remediation effect on Cd.After plant-ing ryegrass,the content of available Mn and available Cd in soil increased significantly compared with the control group,but the total Mn content and total Cd content were lower than the control group.The total Mn content decreased by 206.55-897.41 mg/kg,and the total Cd content decreased by 0.02-0.40 mg/kg.The growth of ryegrass can promote the activation of heavy metals and increase their effec-tiveness,and then fix heavy metals in the body through plant absorption,thereby reducing the content of heavy metals in the external environment.The growth of ryegrass can reduce the migration of heavy met-als to the external environment,reduce the impact of heavy metals on the surrounding environment,and play a certain role in repairing the contaminated soil around the manganese slag yard.