Effect of leachate irrigation on methane oxidation in tropical landfill cover soil

The effect of leachate irrigation on methanotrophic activity in sandy loam-based landfill cover soil with vegetation was investigated. Laboratory-scale experiments were conducted to investigate the methane oxidation reaction in cover soil with and without plants (tropical grass). The methane oxidation rate in soil columns was monitored during leachate application at different organic concentrations and using different irrigation patterns. The results showed that the growth of plants on the final cover layer of landfill was promoted when optimal supplement nutrients were provided through leachate irrigation. The vegetation also helped to promote methane oxidation in soil, whereas leachate application helped increase the methane oxidation rate in nonvegetated cover soil. Intermittent application of leachate (once every 4 days) improved the methane oxidation activity as compared to daily application. Nevertheless, the adverse effects of organic overloading on methane oxidation rate and plant growth were also observed.