Hydraulic Aspects of the Design of a Passive Methane Oxidation Biocover

Passive methane oxidation biocovers (PMOB) have been recently proposed as a viable option for migration residual emissions. The efficiency of a PMOB depends on the degree of saturation, which controls the migration of molecular O₂; a necessary element in the CH₄ oxidation process. The evolution of the degree of saturation S_r is regulated by the unsaturated flow of moisture across the PMOB, which can only be describe with the water retention curve (WRC) and hydraulic conductivity function (k-fct) of the material. This paper discusses the reliability of laboratory-obtained WRCs as input parameter in the prediction of the hydraulic behavior of PMOBs in the field. Three WRC were determined based on field data and in the laboratory using a tension plate. The field data was obtained from an experimental PMOB constructed at St-Nicéphore landfill, Quebec, Canada, where tensiometers and water content probes were installed.