Study On The Vertical Distribution And Bioavailability Of Typical Geotechnical Elements In Longhai,Fujian

Longhai,Fujian,is a typical red soil area in China.It belongs to the subtropical monsoon climate.The natural soil forming process leads to massive leaching and dilution of soil cations,including plant nutrients(Ca,Mg,K,Na,etc.),and soil acidity is strong.Soil acidification will lead to leaching and leaching of heavy metals,aluminum and other chemical elements,and the leaching and depletion of nutrient elements,which will affect the growth and development of crops and the quality of water environment.It will pose a serious threat to the health of animals and human beings,and bring certain ecological risks.In this paper,the Fujian Longhai mining 4 typical soil profiles and 24 soil samples were collected at different depths,the content of heavy metals in soil were determined,explore the distribution and migration of heavy metals in different soil profile;Determination of heavy metal elements in soil samples of 5 kinds of content,explore the bioavailability of typical soil profiles in the law;heavy metal elements of 4 soil profiles of rock samples were determined,comparing the different bedrock weathering products bioavailability characteristics.The results showed that the 4 soil profiles Cr,Cu,Hg,Zn,Ni,Mn and Ti were higher than the national average,while As,Cd,Pb and Zr were lower than the national average.The activities of Cr,Ni and Pb in the soil profile of the middle basic bedrock were relatively low,but increased significantly in the soil profile of the intermediate acid bedrock,while As and Hg had the opposite rule of the two elements.The Cd element is highly active in 4 typical sections,which are 35.11%,31.28%,107.58% and 44.46%,respectively.The active content of heavy metals such as Ni,Cu,Zn,Pb and As is obviously restricted by the physical and chemical properties of soil.As,Cu,Cr and Ni showed strong activity in the 4 soil profiles,and were enriched in deep soil.Pb as a typical man-made pollution element,plus the effect of biological circulation,the surface soil in Section 4 is obviously enriched.Zn has a certain activity of life.It has been enriched to some extent in the deep part after leaching and migration.This study provides an important scientific basis for evaluating the bioavailability of heavy metals in the coastal areas of Fujian,predicting the ecological risk of heavy metals in soil and developing soil remediation.