To describe the long-term coupled behaviour of landfilled municipal solid waste (MSW), this paper proposes a numerical model based on the theories of the conservation of mass, momentum and energy of porous media over a three-phase solid–liquid–gas system. Compared with currently available coupled models, the proposed model can simultaneously simulate such physical processes as phase change, dissolution of the gas phase, the diffusion of its components, evaporation in the liquid phase and changes in the pH of leachate, as well as its solute migration. The finite-volume method was used to numerically discretise the governing equations, with a sequentially iterative technique used for the numerical model of the solution. The corresponding computer code was formulated on the open-source platform OpenFoam. The model was then used to simulate the famous MSW degradation consolidating anaerobic reactor experiment conducted at Southampton University, where the results generally agreed well with the experimental data. The proposed model was also applied to capture spatial and temporal variations in the skeleton of MSW, leachate and landfill gas in a simplified two-dimensional landfill. Overall, the work here provides a basic coupled framework for simulating the long-term behaviours of landfilled MSW. It can be improved upon in future research by implementing other, more reasonable, constitutive relations of MSW.

中文翻译：

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厌氧垃圾填埋场耦合过程的多阶段、多组分模型：理论、实施和验证

为了描述填埋的城市固体废物 (MSW) 的长期耦合行为，本文提出了一种基于固-液-气三相系统中多孔介质的质量、动量和能量守恒理论的数值模型。 . 与现有的耦合模型相比，该模型可以同时模拟相变、气相溶解、组分扩散、液相蒸发和渗滤液pH值变化等物理过程，以及溶质的pH值变化。移民。有限体积方法用于数值离散控制方程，顺序迭代技术用于解决方案的数值模型。相应的计算机代码是在开源平台 OpenFoam 上制定的。该模型随后被用于模拟在南安普敦大学进行的著名的 MSW 降解固结厌氧反应器实验，结果与实验数据基本吻合。所提出的模型还用于捕获简化的二维垃圾填埋场中 MSW、渗滤液和垃圾填埋气骨架的空间和时间变化。总的来说，这里的工作提供了一个基本的耦合框架来模拟垃圾填埋的 MSW 的长期行为。通过实施其他更合理的 MSW 本构关系，可以在未来的研究中对其进行改进。所提出的模型还用于捕获简化的二维垃圾填埋场中 MSW、渗滤液和垃圾填埋气骨架的空间和时间变化。总的来说，这里的工作提供了一个基本的耦合框架来模拟垃圾填埋的 MSW 的长期行为。在未来的研究中，可以通过实施其他更合理的 MSW 本构关系来改进它。所提出的模型还用于捕获简化的二维垃圾填埋场中 MSW、渗滤液和垃圾填埋气骨架的空间和时间变化。总的来说，这里的工作提供了一个基本的耦合框架来模拟垃圾填埋的 MSW 的长期行为。通过实施其他更合理的 MSW 本构关系，可以在未来的研究中对其进行改进。