Gas Permeability and Tortuosity for Packed Layers of Processed Municipal Solid Wastes and Incinerator Residue

Abstract

To make a proper evaluation of gas component movement inside a landfill site, it is important to investigate the different parameters related to gas flow. In this work gas-filled porosity, intrinsic permeability, tortuosity and equivalent pore radius were determined for various packed wastes, such as incineration ash, shredded bulky waste and shredded incombustible waste. These parameters were measured/inferred for samples packed in a column and exposed to a controlled gas flow. The effect of waste conditions, especially the moisture content, on these parameters was also investigated. The intrinsic permeability of such packed wastes was generally in the order of 10(-10) to 10(-9) m2, except for some ash that was one to two orders lower. The tortuosity of waste layer was greater than that of a particulate material and ranged between 2 and 10. The equivalent pore radius was generally in the order of 10(-4) m, which means that gas diffusion is still ordinary in such packed waste layer. The obtained results will be utilized when simulating gas flow inside a landfill site for biogas extraction or site aeration.

Improvement of permeability of waste sludge by mixing with slag or construction and demolition waste

“…6. Table 3 also show literature values for MW-ash, MW-SW, sand, and soil (Tojo, 2002;Kallel et al, 2004;Hirata et al, 1993;Christensen et al, 1996). The k H values of Sludge, Slag, and C&D were close to the minimum of MW-ash, between those of sand and soil, and near the maximum of MW-ash or close to that of soil, respectively.…”

“…Sample characteristics and literature values of incineration ash of municipal solid waste (MSW) (MW-ash), molten slag of MSW (MW-slag), and shredded incombustible MSW (MW-SW), which are the major landfill wastes in Japan (Hanashima et al, 1988;Sekito et al, 1997;Tojo, 2002;Kallel et al, 2004;Park et al, 2007), are summarized in Table 1. Sludge had the highest moisture content.…”

“…Gas permeability, tortuosity, equivalent pore radius, and saturated hydraulic conductivity Measurements of gas permeability, tortuosity, and equivalent pore radius were conducted with reference to the report of Kallel et al (2004). These parameters are expected to change with the moisture content of the layer.…”

“…1.3 Â 10 À4 1.3 Â 10 À4 1.9 Â 10 À4 1.1 Â 10 À4 1.0 Â 10 À7 1.7 Â 10 À4 2.4 Â 10 À4 3.9 Â 10 À5 2.1 Â 10 À5 -3.3 Â 10 À4b 1.3 Â 10 À4 -7.1 Â 10 À4b --Oxygen consumption rate e ÀR 1 [mol/(d m 3 )]3.9 Â 10 À1 1.8 Â 10 À1 1.3 Â 10 À1 5.9 Â 10 À2 1.7 Â 10 À2 3.9 Â 10 0 5.0 Â 10°5.5 Â 10 0 5. Kallel et al (2004). c Hirata et al, 1993.…”

Environmental Geotechnics Related to Landfills of Municipal Solid Wastes

“…However, much fewer experimental data for this parameter are available for the design as compared with those for the water permeability of MSWs. One exception to this is the laboratory study conducted by Kallel et al (2004), in which the gas permeability and tortuosity for the processed MSWs and incinerator residue generated in Japan were investigated. The major findings from the laboratory study are as follows.…”