Quantifying the Effects of Moisture Content on Transport and Adsorption of Methane through Biochar in Landfills

This study was aimed at investigating the effects of moisture content (MC) on the methane transport and adsorption through wood-pellet biochar (CE-WP2) and comparing those results with that of a more conventional adsorbent, granular activated carbon (GAC). Laboratory column adsorption tests were conducted under dry conditions and at two levels of moisture content at three different landfill gas inflow rates. The breakthrough curves from column studies were modeled using the 1-D advection-diffusion equation by accounting for both the transport and adsorption processes affecting the system under different levels of MC. The presence of moisture negatively affects the methane adsorption onto both materials with more pronounced influence in the case of GAC. The methane diffusion coefficients were modeled under dry and wet conditions for CE-WP2 and GAC. Results from this study show that the modeled methane diffusion coefficients for CE-WP2 were higher than that of GAC. Overall, this study provides critical information to design a novel biocover for landfills by incorporating biochar as a sustainable cover material to mitigate current CH₄ emissions.