碳纳米管在膨润土防水毯中迁移规律的研究

发布时间：2018-11-08 17:16

【摘要】：纳米技术目前在各领域都有广泛的应用,而纳米粒子对环境和生物系统产生的毒性危害也日益引起人们的重视。现有的固体废弃物填埋场防污屏障系统设计时并没有考虑对纳米颗粒的拦截,这极有可能导致今后纳米颗粒透过防污屏障系统进入到环境中去,从而对环境产生潜在的危害。本文通过对碳纳米管在防污屏障系统中的运移规律进行研究,建立能够反映和描述纳米颗粒在防污屏障系统中的运移规律的数学模型,计算它的解析解,并结合有限元软件开展数值模拟。同时通过渗透试验等手段,对防污屏障采用的膨润土防水毯材料进行试验,评价其对碳纳米管的拦截能力,并为数学模型和数值计算提供计算参数。研究结果为有效改善现有防污屏障系统的设计方法,提高其对碳纳米颗粒的拦截能力,提供了一定的设计依据,对避免日后纳米粒子可能造成对环境和生物系统的潜在危害,具有非常重要的意义。主要研究结果如下:(1)本文通过常水头渗透试验对碳纳米管在单层膨润土防水毯中运移的研究表明:其渗透系数在随着时间的增加逐渐减小,并在同一个时刻下,渗透系数随着压力的增大而减小,而且其渗透系数与压力的对数成明显的线性关系。(2)采用烘干称重法对碳纳米管渗滤液的浓度作了定量测定,研究发现膨润土防水毯对碳纳米管的平均拦截率达到了95%;(3)通过提出分段线性函数边界条件和引入压力影响系数,建立了可以较好地描述碳纳米管在膨润土防水毯中运移规律的数学模型,并得到其解析解;(4)采用有限元分析软件SEEP/W和CTRAN/W,模拟分析了碳纳米管在膨润土防水毯中的运移过程,其结果与试验和理论得到的结果相一致。
[Abstract]:Nanotechnology has been widely used in various fields, and the toxicity of nanoparticles to the environment and biological systems has attracted more and more attention. The existing solid waste landfill antifouling barrier system does not consider the interception of nanoparticles, which may lead to the future entry of nanoparticles into the environment through the antifouling barrier system, thus causing potential harm to the environment. In this paper, by studying the migration law of carbon nanotubes in antifouling barrier system, a mathematical model which can reflect and describe the migration law of nanoparticles in antifouling barrier system is established, and its analytical solution is calculated. Numerical simulation is carried out with finite element software. At the same time, the bentonite waterproof blanket material used in antifouling barrier was tested by means of permeation test to evaluate its ability to intercept carbon nanotubes, and to provide calculation parameters for mathematical model and numerical calculation. The results provide a basis for the design of the existing antifouling barrier system, improve its ability to intercept carbon nanoparticles, and avoid the potential harm to the environment and biological system caused by the nanoparticles in the future. Of great significance. The main results are as follows: (1) in this paper, the migration of carbon nanotubes in monolayer bentonite waterproof blanket is studied by the constant head permeation test. The results show that the permeability coefficient decreases gradually with the increase of time, and at the same time, The permeability coefficient decreases with the increase of pressure and the logarithm of pressure is linear. (2) the concentration of carbon nanotube leachate is measured quantitatively by dry weighing method. It was found that the average interception rate of bentonite waterproof blanket to CNTs was 95%. (3) by proposing the boundary condition of piecewise linear function and introducing pressure influence coefficient, a mathematical model which can describe the migration law of carbon nanotubes in bentonite waterproof blanket is established, and its analytical solution is obtained. (4) the migration process of carbon nanotubes in bentonite waterproof blanket is simulated by finite element analysis software SEEP/W and CTRAN/W,. The results are consistent with the experimental and theoretical results.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU57

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