Methane oxidation in a boreal climate in an experimental landfill cover composed from mechanically-biologically treated waste.
The present study evaluated microbial methane (CH4) oxidation in a boreally located outdoor landfill lysimeter (volume 112 m3, height 3.9 m) filled with mechanically-biologically treated waste (MBT residual) and containing a cover layer made from the same MBT residual. The calculations based on gas emission and pore gas measurements showed that, between April and October 2005, a significant proportion (> 96%) of the methane produced (< 23 l CH4 m(-2) d(-1)) in the lysimeter was oxidized. Methane was oxidized mainly at the depths of 35-75 cm, as indicated by the upward decrease both in the methane concentration and in the methane-to-carbon dioxide ratio in the pore gas. Lower methane oxidation (< 0.8 CH4 m(-2) d(-1); this was < 22% of the methane produced) was observed only during the coldest time of the year (January 2006), apparently due to the fall in temperature at the depths of 25-70 cm (from 9-25 degrees C during April to October to 2-9 degrees C in January). Unexpectedly, the highest methane oxidation potential (MOP) was observed in samples from the top layer where exposure to methane was low. Overall, the results show that MBT residual is a suitable support medium for methane oxidation in landfill covers in field conditions in a boreal climate.
Einola
J-K M
JK
Department of Biological and Environmental Sciences, P.O. Box 35, FIN-40014 University of Jyväskylä, Finland. juha.einola@bytl.jyu.fi
Sormunen
K M
KM
Rintala
J A
JA
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000032:analysis; D003081:Cold Climate; D052918:Environmental Restoration and Remediation / Q000379:methods / Q000592:standards; D006863:Hydrogen-Ion Concentration; D055595:Mechanical Phenomena; D008697:Methane / Q000032:analysis* / Q000737:chemistry; D008961:Models, Structural; D010084:Oxidation-Reduction; D016062:Porosity; D012037:Refuse Disposal / Q000379:methods / Q000592:standards; D012621:Seasons; D013696:Temperature; D014866:Waste Products / Q000032:analysis*
D000393:Air Pollutants; D014866:Waste Products; D002245:Carbon Dioxide; D008697:Methane