Effects of Hydrophobic Biochar-Modified Landfill Soil Cover on Methane Oxidation

Environ Manage. 2024 Apr;73(4):769-776. doi: 10.1007/s00267-023-01910-0. Epub 2023 Nov 9.

Abstract

Landfill cover soils play an important role in mitigating landfill methane (CH4) emissions. Incorporating biochar into the soil has proven effective in reducing CH4 emissions. However, the role of hydrophobic biochar in this context remains underexplored. This study investigated the CH4 removal efficiency of a biochar-modified landfill soil cover column (RB) and hydrophobic biochar-modified landfill soil cover column (RH) under varying CH4 influx gas concentrations (25 and 35%), simulated CH4 inflow rates (10, 15, and 20 ml/min), and temperatures (20, 25, 30, 35, and 40 °C). RH consistently outperformed RB in terms of CH4 removal efficiency under these experimental conditions. The optimal conditions for CH4 degradation by both RB and RH were observed at a CH4 influx gas concentration of 35%, a simulated CH4 inflow rate of 10 ml/min, and a temperature of ~30 °C. RH achieved a CH4 removal rate of up to 99.96%. In summary, the addition of hydrophobic biochar enhanced the air permeability and hydrophobicity of landfill cover soils, providing a promising alternative to conventional cover soils for reducing CH4 emissions from landfills.

Keywords: Hydrophobic biochar; Landfill cover; Landfill gas; Methane oxidation.

MeSH terms

  • Charcoal / chemistry
  • Methane*
  • Oxidation-Reduction
  • Refuse Disposal*
  • Soil / chemistry
  • Soil Microbiology
  • Waste Disposal Facilities

Substances

  • Methane
  • Soil
  • biochar
  • Charcoal