Enhancing Methane Oxidation in Landfill Cover Soil Using Microbially Activated Biochar: A Sustainable Approach for Mitigating Greenhouse Gas Emissions

Abstract

Landfill gas, primarily composed of methane (CH₄) and carbon dioxide (CO₂), poses significant environmental and health risks due to its contribution to greenhouse gas emissions and potential explosive hazards. This study proposes an efficient way to lower methane emission amended cover soil with biochar and microbially activated biochar (MAB), Because microbial acclimation causes an initial lag phase, adding biochar to landfill cover soil lowers the rate of CH₄ oxidation. Activated biochar, which is produced by converting biochar induced with methane oxidizing bacteria, shortens the acclimation period and increases the methane oxidation activity. In this study series of Batch experiments were conducted to evaluate the methane oxidation capacity of soils amendment with various proportions of biochar. Results demonstrated that MAB-amended soils significantly enhanced methane oxidation rates (213 mg/g) compared to non-activated biochar–amended soils (195.11 mg/g) and biochar alone (32 mg/g). Microstructural, chemical, and mineralogical analyses using SEM, EDX, and XRD revealed that MAB provides an ideal environment for microbial colonization, thereby improving methane oxidation. This study highlights the potential of MAB as an effective strategy for mitigating methane emissions from landfills.