Experimental Characterization of the Thermal, Hydraulic and Mechanical (THM) Properties of Compost Based Landfill Covers

• Main Author: Bajwa, Tariq Mahmood
• Language: en
• Published: 2012
• Subjects: Thermal; hydraulic; mechanical; chemical; coupled; free air space; degree of saturation; column
• Online Access: http://hdl.handle.net/10393/20518

Landfills are considered to be one of the major sources of anthropogenic methane (CH4) emissions in the environment. A landfill biocover system optimizes environmental conditions for biotic CH4 consumption that controls the fugitive and residual emissions from landfills. A compost material has more oxidation potential in comparison to any other material due to its high porosity, organic content, free flux for gases and water holding capacity. Thermal, hydraulic, bio – chemical and mechanical (THMCB) properties are important factors that can significantly affect the performance of biocover material with regards to CH4 oxidation potential as well as structural stability. Technical data on the thermal, hydraulic and mechanical (THM) properties of compost based biocover materials are quite limited. Hence, a detailed experimental program has been carried out at the University of Ottawa to study the THM properties and behaviour of compost biocover material by conducting experimental tests on small compost samples as well as by performing column experiments. The test results indicate that lower water content (dry of optimum for compaction curve) shows more free air space (FAS) in comparison to higher water content. The compost has almost the same shear strength for various initial water contents and dry unit weights; however, it settles and swells more at higher water content than lower water content per mechanical test results. The thermal and hydraulic properties of compost are a function of the compaction degree in addition to various other parameters. It is also found that the THM properties of compost are strongly coupled and the degree of saturation greatly affects the FAS.