Landfills are one of the major sources of
methane (CH4) emission which is a very potent greenhouse
gas. The use of a natural process for microbial CH4
oxidation through biocovers provides a source reduction of
CH4 emission. Previous studies have mostly focused on
biochemical properties, and limited research has been
conducted with regards to the geotechnical
characterization of biochar based biocovers. This paper
presents the results of a comprehensive laboratory
investigation on laterite, Igbokoda sand and their mixtures
with biochar at 2%, 4%, 8%, 10% and 20% to determine
the compaction properties of biochar based biocovers.
From the result, it was shown that the laterite has medium
plasticity while the Igbokoda sand is non-plastic. Also,
Addition of biochar to landfill cover soil increased the
particle sizes, and consequently the porosity of the soil is
increased which can promote the air flow through the
landfill cover. Thus, greater O2 diffusion within the
landfill cover will result, leading to higher microbial
oxidation/degradation of CH4. Maximum dry unit weight
decreased and the optimum water content partly increased
as the biochar content increased with the two samples.
Compaction test results show that when biochar content
varied from 0 to 20% for the laterite, the maximum dry
unit weight decreased from 1660kg/m3 to 1330kg/m3 and
decreased from 1590kg/m3 to 1390kg/m3 for Igbokoda
Sand. Thus, the results presented in this paper will
contribute to a better understanding of the geotechnical
behaviour of biochar based biocover.
Geotechnical characterization of peat-based landfill cover materials