Summary of Experimental Study on Chemical Blocking Characteristics of Compacted Clay Liners in Landfill
Abstract: Compacted bentonite geosynthetic clay liner for sale is often used as an engineering barrier to prevent outward migration of pollutants in landfills. This paper reviews the infiltration, adsorption and diffusion characteristics of pollutants in compacted clay through a review of domestic and foreign scholars, thus providing a theoretical basis for practical engineering bentonite geosynthetic clay liner factory price.
Keywords: compacted clay liner; contaminant migration; infiltration; adsorption; diffusion; bentonite geosynthetic clay liner manufacturers
At present, the domestic main use of sanitary landfill method to treat urban waste, through the establishment of landfills, solid waste buried in the ground, sealed and maintained management. This can effectively reduce a series of environmental problems caused by garbage dumping bentonite geosynthetic clay liner for sale. However, with the rainfall infiltration in the landfill and the compression degradation of the waste high quality bentonite geosynthetic clay liner, a large amount of leachate will be produced, which contains a large amount of toxic and harmful pollutants, which is more serious to human health. Therefore, as a landfill liner system that blocks the leachate from oozing out and preventing the outward diffusion of pollutants wholesale bentonite geosynthetic clay liner, it is particularly important to study its chemical retardation characteristics bentonite geosynthetic clay liner manufacturers.
The compacted clay liner is a suitable anti-seepage gasket material because it not only can effectively reduce the leakage of groundwater or leachate but also has good adsorption performance and low-cost bentonite geosynthetic clay liner factory price.
2. Study on chemical retardation characteristics
2.1 Study on permeability characteristics
As a clay liner that prevents leachate from infiltrating into the landfill, seepage prevention is its most basic function. The permeability coefficient of clay liner is a basic indicator to measure its anti-seepage performance. Due to the complex environment of clay liners in landfills bentonite geosynthetic clay liner for sale, domestic and foreign scholars have done a lot of research on their anti-seepage properties. In this paper, the factors affecting the permeability coefficient of the liner are divided into two aspects: internal and external factors. In terms of internal factors, Yucel found that the more the amount of sepiolite incorporated into the liner, the smaller the permeability coefficient of the liner, which is due to the higher clay content, specific surface area, and plasticity index of sepiolite high quality bentonite geosynthetic clay liner. Noureddine and Aldaeef also pointed out that soil density and plasticity have a greater impact on the permeability coefficient. In terms of the external environment, Aldaeef pointed out that the permeability coefficient of Halton clay increased by 12 times under the conditions of dry and wet circulation, while the permeability coefficient of mixed soil mixed with bentonite was almost unaffected. In addition, Aldaeef’s research results show that the introduction of simulated leachate in soil samples will reduce the permeability coefficient of the sample wholesale bentonite geosynthetic clay liner, which is consistent with the conclusion of Li (2013), because chemical precipitation blocks the pores of soil particles, thereby reducing soil. The effective pore volume.
2.2 Study on adsorption characteristics
Adsorption refers to a process in which a solute is immobilized in a solution from a free ionic state onto a solid surface. Metal ions often undergo physical adsorption such as chemical adsorption and electrostatic adsorption on the surface of the soil such as ion exchange and surface precipitation bentonite geosynthetic clay liner for sale. For the study of the adsorption characteristics of compacted bentonite geosynthetic clay liner factory price, domestic and foreign scholars often carry out the bulk adsorption test of clay and the soil column test of the compacted state. Tanit carried out a batch adsorption test on different red ions of red clay and pointed out that the Freundlich model has a good fitting effect on red clay. The adsorption amount of different metals mainly depends on the ion species itself. When Du (2006) conducted an adsorption test on marine soft soil high quality bentonite geosynthetic clay liner, it was found that the adsorption amount of Pb was higher than Cd, which was consistent with the Tanit result. Chotpantarat, Putthividhya and other scholars investigated the effects of pH, ion type, etc. on the competitive adsorption between single, two and multiple ions, and used HYDRUS-1D, HYDRUS-2D and other software to simulate the solute breakthrough curve, fully indicating the adsorption point The limited result is competitive adsorption between a plurality of ions wholesale bentonite geosynthetic clay liner, so that the adsorption rate of the same ion in the mixed solution is lowered.
2.3 Study on diffusion characteristics
The migration of pollutants in compacted clay mainly involves three processes of convection bentonite geosynthetic clay liner for sale, adsorption, and diffusion. Shackelford’s research shows that when the permeability coefficient of soil is large, pollutants migrate mainly by convection; when the permeability coefficient of soil is small Diffusion is an important way for pollutants to migrate outward. Therefore bentonite geosynthetic clay liner factory price, it is necessary to study the diffusion characteristics of contaminants in the liner.
Diffusion consists of molecular diffusion caused by concentration gradients and mechanical dispersion that is continually diverging in the solute flow due to differences in pores in the soil. At present bentonite geosynthetic clay liner manufacturers, laboratory experiments on diffusion characteristics mainly include steady-state diffusion and non-steady state diffusion tests high quality bentonite geosynthetic clay liner. The diffusion coefficient of pollutants is often measured by the diffusion coefficient. For steady-state diffusion, the diffusion coefficients are divided into four types: self-diffusion, tracer diffusion, salt diffusion, and back diffusion wholesale bentonite geosynthetic clay liner, which are susceptible to solute ion type, pH, and the influence of factors such as concentration.
At present, the experimental research on the infiltration bentonite geosynthetic clay liner for sale, adsorption and diffusion characteristics of compacted clay has been relatively mature at home and abroad wholesale bentonite geosynthetic clay liner. Through laboratory tests to study the chemical retardation characteristics of compacted clay high quality bentonite geosynthetic clay liner, the pollutant migration model can be further established to estimate the service life of the compacted clay liner in the landfill, providing a theoretical basis for practical engineering.