Experimental Study And Theoretical Study On Permeability Of Carbon Nanotubes In Geosynthetics Clay Liner

The number of landfills across the country has more than 20,000,the future will also build a large number of landfills,landfill disposal pollution control is an urgent need to solve the environmental problems.In recent years,To study the permeability of pollutants in landfill,and to study the effects of pollutants on groundwater,has become an important issue for domestic and foreign scholars.With the rapid development and widely used of the nanoparticles technology will inevitably lead to end up in solid waste landfill site on pollutant concentration of nanoparticles will be more and more big.And the toxicity of nanoparticles have been very in-depth study at home and abroad scholars.At present,the research on the law of nanoparticle migration in landfill gasket system is still blank,and foreign countries have just started.No one has yet to go to further research and no research results can be applied.In view of this,it is very important to study the permeation law of carbon nanometer particles in the geosynthetic clay liner(GCL).In this paper,a series of experimental studies on the permeation of ultra-high purity single-walled carbon nanotubes(CNTs)in GCL were carried out by means of GDS flexible wall permeation apparatus.Then,the author amend the concentration equation of single-walled carbon nanotubes in GCL considering the particularity of carbon nanotubes and combining with the experimental results.Finally,GMS finite element software was used to simulate the migration of single-walled carbon nanotubes in the landfill system.The main work was as follows:(1)The permeation test of ultra-high purity single-walled carbon nanotube dispersion in single-layer GCL and double-layer GCL was carried out respectively by GDS triaxial flexible wall permeation instrument.The permeability of ultra-high purity single-walled carbon nanotube dispersion in single-layer GCL and double-layer under different osmotic pressures was studied.And the solution through GCL was tested,which provided the necessary parameters for the subsequent theoretical research and finite element simulation.(2)Single-walled carbon nanotubes in the GCL migration second-order convection diffusion equation is established by considering the case where the migration of single-walled carbon nanotubes in GCL is transient.The concentration equation is corrected directly by considering the particularity of single-walled carbon nanotubes.This particularity includes The interaction between the charge of carbon nanotubes and the charge of sodium base bentonite in GCL and unique mechanical,electrical and chemical properties.Under the assumption that the correction factor is 1,the pollutants accumulated at the bottom of the GCL quality are obtained by the use of MATLAB.And compared with the experimental results,obtained different correction coefficient for single layer GCL and double GCL.Finally,the cumulative flux through the bottom of the GCL is extended to 100 years,And compared and analyzed,which gives the landfill design,construction of some of the recommendations and methods.(3)With the help of GMS finite element analysis software,the author makes a simple simulation of the migration law of single-walled carbon nanotubes in landfill system.The model uses the grid model to establish the MODFLOW model.The migration law of single-walled carbon nanotubes in landfill was simulated by MODPATH particle beam tracer technique in GMS.And compared with the experimental and theoretical results.