Investigation of Alternative Materials for Biogeochemical Landfill Cover to Mitigate Landfill Gas Emissions: Column Experiments

Fugitive emissions of landfill gas (LFG), primarily consisting of methane (CH4) and carbon dioxide from municipal solid waste (MSW) landfills, pose significant risks and environmental concerns if not captured. To address this, researchers at the University of Illinois Chicago developed an innovative biogeochemical cover (BGCC) system. This system features two layers - a biochar-amended soil (BAS) and basic oxygen furnace (BOF) slag - designed to simultaneously reduce CH4 and CO2 emissions from MSW landfills to achieve a Zero Emissions Landfill Cover. Laboratory column and near-field scale tank experiments using the BGCC system, specifically with pinewood-derived biochar (PW-BAS) and BOF slag (labeled as BGCC-PWBOF), have demonstrated significant potential to simultaneously eliminate CH4 and CO2. However, the reliance on PW-derived biochar and BOF slag for large-scale implementation may encounter challenges due to their limited availability near landfill sites. Hence, there is a need to identify and evaluate alternatives to PW-biochar and BOF slag as part of the BGCC system. Consequently, this study aims to evaluate and compare the performance of a newly developed BGCC system, labeled as BGCC-RHCKD, which uses rice husk (RH)-derived biochar as an organic amendment and cement kiln dust (CKD) as a CO2 sequestration layer, with the previously developed BGCC-PWBOF and a soil cover (SC) as a control in a laboratory column experiment.