ABSTRACT Recent advancements in methane oxidation biosystems (MOBs) highlight the potential of structured engineered media (STEM)—organic materials with a heterogeneous particle size distribution—as an effective oxidation media. Despite their growing use, geotechnical characterization and determination of hydraulic parameters of STEM remain in its early stages. The air permeability function, specifically, is a critical function used for determination of the occlusion point, which is a critical design parameter for MOBs. It indicates where the flow becomes restricted, causing a reduction in methane oxidation efficiency. This study introduces a practical methodology for measuring the air permeability and obtaining the air permeability function. This method uses a custom-built cell inspired by rigid-wall permeameters, allowing for the inclusion of large, structured particles and preserving the macrostructure of the sample. This method enables the rapid and accurate obtention of the occlusion points for compost-based materials. Initial results show consistency across materials of the same composition suggesting the reliability of the method. Although some influencing factors remain to be explored, the results show strong potential for integration into the geotechnical assessment framework for STEM usage in MOB. Moreover, the reference values obtained for occlusion points can be used as a reference in the design and performance assessment of MOBs.
Dulac et al. (Tue,) studied this question.