Solidification Experimental Study And Mechanism Analysis Of Heavy Metals Contaminated

With the rapid development of industrial technology,the problem of heavy metal pollution on the land has become increasingly serious.In order to solve the deficiencies in the existing methods for the disposal of heavy metal contaminated soil,this paper,based on the solidification stabilization method,takes the safe disposal of heavy metal Pb,Cd,and Cu composite contaminated soil samples as the starting point,and proposes a heavy metal contaminated soil The disposal method of resource utilization,and is adapted to a new type of heavy metal compound contaminated soil solidification agent A.On this basis,the solidification test of heavy metal contaminated soil and the microscopic characteristic analysis test were carried out The performance of the solidified body of heavy metal contaminated soil was analyzed from the aspects of mechanical properties,deformation characteristics and leaching characteristics,and the internal composition of heavy metal contaminated soil before and after solidification was observed and analyzed from the microscopic view.Structural changes,and discuss the solidification mechanism of heavy metal contaminated soils.The main research results are as follows:(1)The heavy metal contaminated soil disposal method and new curing agent proposed in this paper have a good solidification effect on heavy metal contaminated soil in mining areas.After solidification,the unconfined compressive strength and deformation resistance of heavy metal contaminated soil are greatly improved,and the leaching concentration of heavy metals is far below the environmental safety standard limit.(2)The solidification mechanism of heavy metal contaminated soil is mainly manifested in two aspects.One is to significantly reduce the content of weak acid-extracted heavy metals in the soil and effectively convert them into a residue state.On the other hand,the hydration product of the curing agent effectively fills the voids between the contaminated soil particles and plays a certain role in cementing,making the overall structure of the contaminated soil more stable and dense,and effectively improving the mechanical properties of the heavy metal contaminated soil.At the same time,it also has a certain inhibitory effect on the leaching of heavy metals through adsorption,wrapping,and ion exchange.(3)From the perspective of mechanical properties,the contaminated soil cured by the new curing agent has better mechanical properties,the unconfined compressive strength can reach up to 33.45 MPa and the lowest is 3.22 MPa.On the whole,the most critical factor affecting the mechanical properties of the cured body is the amount of curing agent,but simply considering adding more curing agent to improve the mechanical properties of the cured body may and achieve the desired effect.(4)The solidified body of heavy metal contaminated soil has better resistance to deformation,and with the increase of the curing agent content,the failure strain decreases continuously under the compressive load,the deformation modulus E50 continuously increases,and the initial pollution degree is different.The contaminated soil solidification trend is consistent.(5)From the perspective of leaching characteristics,the new curing agent has a good curing effect on the composite heavy metal contaminated soil.Only the heavy metal contaminated soil requires a curing agent content of 10%to achieve the purpose of safe disposal.Other initial pollution levels for the heavy metal contaminated soil,the solidifying agent content reaches 5%to achieve the purpose of safe disposal.