Gas transport parameters such as gas diffusivity (D_p/D₀), air permeability (k_a), and their dependency on void space (air-filled porosity, ε) in a waste body govern convective air and gas diffusion at solid waste dumpsites and surface emission of various gases generated by microbial processes under aerobic and anaerobic decompositions. In this study, D_p/D₀(ε) and k_a(ε) were measured on dumping solid waste in Japan such as incinerated bottom ash and unburnable mixed waste as well as a buried waste sample (dumped for 20 years). Sieved samples with variable adjusted moistures were compacted by a standard proctor method and used for a series of laboratory tests for measuring compressibility, saturated hydraulic conductivity, and gas transport parameters. Results showed that incinerated bottom ash and unburnable mixed waste did not give the maximum dry density and optimum moisture content. Measured compressibility and saturated hydraulic conductivity of tested samples varied widely depending on the types of materials. Based on the previously proposed D_p/D₀(ε) models, the diffusion-based tortuosity (T) was analyzed and unique power functional relations were found in T(ε) and could contribute to evaluating the gas diffusion process in the waste body compacted at different moisture conditions.

中文翻译：

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压实固体废物气体传输特性的表征

气体传输参数，例如气体扩散（d _p / d ₀），空气渗透率（K_一在废物体），以及它们对空隙空间依赖性（空气填充的孔隙度，ε）支配对流空气和气体扩散在固体废物垃圾场微生物过程在需氧和厌氧分解下产生的各种气体的表面排放。在这项研究中，d _p / d ₀（ε）和k_一（ε）是在日本对倾倒的固体废物（如焚化的底灰和不可燃的混合废物）以及掩埋的废物样品（倾倒20年）进行测量的。筛分后的水分含量经过可变调节的样品通过标准监理器方法进行压实，并用于一系列实验室测试，以测量可压缩性，饱和水力传导率和气体传输参数。结果表明，焚烧的底灰和不可燃的混合废物没有提供最大的干密度和最佳的水分含量。根据材料类型的不同，测得的样品的可压缩性和饱和导水率差异很大。基于先前提出的D _p / D ₀（ε）模型，分析了基于扩散的曲折度（T），并在T（ε）中发现了独特的幂函数关系，这有助于评估在不同湿度条件下压实的废物体内的气体扩散过程。