Shanujah, M and Deepagoda, T K K C and Karunarathna, A K and Nasvi, M C M and Shreedharan, V and Babu, G L S and Smits, K M and Oldenburg, C M (2020) Effects of �soil-like� particle size on gas transport and water retention properties in aged municipal solid waste from a Sri Lankan open dumpsite. In: Soil Science Society of America Journal, 84 (4). 1080 -1093.
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Abstract
Open dumps constitute a major source of greenhouse gases (GHGs), predominantly methane and carbon dioxide, in developing countries. In an aged dump, typical waste composition is dominated by the �soil-like� fraction of which physical, hydraulic and gas transport characteristics markedly affect GHG emissions. This study characterized soil-gas diffusivity (Dp/D0), soil-water characteristics (SWC), and particle size distribution in �soil-like� fractions of aged solid waste retrieved at 2.5�5 m depth from an old open dumpsite situated at Kurunegala, Sri Lanka. The �soil-like� fraction was proportioned into three groups based on particle size (0�4.75, 4.75�9.5, and 9.5�25 mm) to investigate the particle size effect on Dp/D0 and SWC. The simulated methane concentration profiles in different size groups were also examined using the transport simulator TOUGH2-EOS7CA based on the multiphase flow of multicomponent gas mixture (methane, water vapour and air) under dry and half-saturation conditions across a predefined temperature gradient. The results highlighted distinct two-region characteristics (i.e., inter-aggregate and intra-aggregate pore regions) in all three size fractions which could be adequately parameterized with existing and modified bimodal functions. We proposed a useful practical tool for estimating Dp/D0 for known mean particle size and volumetric water content in the absence of direct measurements. The results further revealed that Dp/D0 is particle-size dependent; however, Dp/D0 remained invariant across all size fractions at the volumetric water content of �0.22�0.25 cm3 cm�3. Numerical results further showed a pronounced effect of particle size and soil moisture on gas transport properties. © 2020 The Authors. Soil Science Society of America Journal © 2020 Soil Science Society of America
Item Type: | Journal Article |
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Publication: | Soil Science Society of America Journal |
Publisher: | John Wiley and Sons Inc. |
Additional Information: | The copyright for this article belongs to authors |
Keywords: | Aggregates; Carbon dioxide; Developing countries; Gas emissions; Greenhouse gases; Methane; Particle size; Particle size analysis; Soil moisture, Gas transport properties; Methane concentrations; Multicomponent gas-mixtures; Particle size effect; Region characteristics; Soil water characteristics; Volumetric water content; Water retention properties, Municipal solid waste |
Department/Centre: | Division of Mechanical Sciences > Civil Engineering |
Date Deposited: | 23 Aug 2021 07:26 |
Last Modified: | 23 Aug 2021 07:26 |
URI: | http://eprints.iisc.ac.in/id/eprint/66340 |
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