Proposal of applicable conditions for methanotrophs activity in a final cover material of waste disposal site

Abstract

Waste disposal site discharges carbon dioxide gas and methane gas due to decompose waste by microorganism. Methane gas is a kind of green house gas. The countermeasure which is oxidative decomposition of methane by methanotrophs is proposed to reduce methane gas. The oxidative decomposition by methanotrophs needs oxygen gas, methane gas and water. Therefore, a final cover material has to have suitable air permeability and hydraulic conductivity. In this study, the authors carried out the water retentivity test of soil and the measurement of natural water content under the nearly constant relative humidity to candidate material which is Kanto loam, two kinds of coal ash, water-granulated slag and pit sand. The authors discussed the experimental results and proposed the design method of a final cover material from matric potential and evaluated from volumetric gas content.