The Migration Characteristics Of Heavy Metal Lead Ions In The Presence Of Graphene Oxide

With the improvement of the world economy,the improvement of people’s living conditions,and the development of industrialization,the environment on which mankind depends for survival has been destroyed.The heavy metal ion pollutants such as lead,chromium,and copper in the atmosphere,water,and soil have large residual amounts,which are harmful to dynamic animal,plant and human health.Aiming at the purification mechanism of heavy metal pollutants in permeable soil layers in environmental geotechnical engineering,this paper conducts experimental research on the migration characteristics and purification measures of pollutants under the conditions of changes in seepage velocity and concentration:(1)In the experiment,graphene oxide was used to configure a suspension with a concentration of 0.1g/L and 0.05g/L,and Pb(NO3)2 was configured to a solution with a concentration of 100ng/m L and 400ng/m L,at 0.087cm/s,0.173cm/s,0.260cm/s three flow rates were injected into the saturated quartz sand matrix,combined with the adsorption and desorption of lead ions in the quartz sand matrix,the migration process of graphene oxide and lead ions,and the deposition and adsorption in the matrix were studied.The quantity distribution characteristics and the influencing factors of lead ion removal.(2)A study on the migration process of graphene oxide has been carried out.The results show that the increase in seepage speed is beneficial to the migration of graphene oxide in the quartz sand matrix.The concentration of graphene oxide in the effluent increases by 10% and the amount of graphene oxide deposition decreases;increased concentration will also promote the migration of graphene oxide.The graphene oxide concentration ratio in the effluent is 2.2 greater than the graphene oxide concentration ratio of the injected solution 2,and the deposition ratio 1.2 is less than the injected graphene oxide concentration ratio 2;the deposition distribution is characterized by distance the farther the injection end is,the smaller the deposition amount.The adsorption-desorption test of lead ions in the quartz sand matrix showed that: during the adsorption process,when the solution concentration increases,the growth rate of the lead ion adsorption capacity slows down;during the desorption process,as the solution concentration decreases,the lead ion release rate sudden acceleration is more suitable with the nonlinear adsorption-desorption model.The results of the lead ion migration test show that: different seepage speeds have no significant effect on lead ion migration;increasing the lead ion concentration from 100ng/m L to 400ng/m L will promote the migration of lead ions,and the lead ion concentration in the effluent in the first stage will increase from 45ng/m L to 250ng/m L,the adsorption amount of lead ions in the quartz sand matrix also increases;the adsorption amount distribution is characterized by the farther away from the injection end,the smaller the adsorption amount.The lead ion adsorption-desorption model can be used to explain the experimental phenomenon of lead ion migration.(3)A study on the removal of lead ions from the matrix by graphene oxide has been carried out,the results show that the faster the seepage rate and the greater the concentration of graphene oxide injected,the more helpful the removal of residual lead ions.The overall removal effect is better,and different factors can cause different removal rates by comparing the amount of residual lead ion adsorption.