Abstract: To solve the environmental problems caused by the unorganized release of landfill gas from old landfills,a biological blanket using biochar as a medium was proposed. In addition to be able to improve the oxidation capacity of CH₄,it could also absorb greenhouse gas which were dominated by CH₄ and CO₂. By conducting a batch of adsorption experiments,it was found that the biochar could increase the adsorption capacity of soil CH₄ and CO₂,and the maximal value of gas adsorption of the modified soil with 20% biological carbon was increased by one order of magnitude; The adsorptions of CH₄ and CO₂ in the biochar modified soil were conformed to the pseudo-second-order equation,indicating that the adsorption process applied union control through surface adsorption and intra-particle diffusion. The equilibrium adsorption data of CH₄ and CO₂ in the modified soil was analyzed with the Langmuir isothermal adsorption model. The result of nonlinear fitting was ideal. The 1 kg modified soil with 20% biological carbon could adsorb 0.012 mol CH₄ and 0.043 mol CO₂ at maximum.

Key words: silt, biochar, methane, carbon dioxide, batch test, kinetics