Spatial variability of soil gas concentration and methane oxidation capacity in landfill covers

Can soil gas profiles be used to assess microbial CH4 oxidation in landfill covers?

“…For the 40 samples from the landfill cover soil, CH 4 oxidation rates varied between 0.0063 and 1.4 lmol CH 4 g À1 dw h À1 (0.1 and 22 lg CH 4 g À1 dw h À1 , see also Röwer et al, 2011) and respiration rates ranged between 0.0045 and 0.32 lmol CO 2 g À1 dw h À1 (0.2 and 14 lg CO 2 g À1 dw h À1 ). When the evolution of CO 2 from respiration is compared to the evolution of CO 2 from the combined processes of CH 4 oxidation and respiration (Fig.…”

Methane emission reduction from storage of manure and digestate-slurry

“…The activity of the established bacterial community depends largely on the soil temperature and the soil gas exchange with the atmosphere. Several studies address the optima of soil material and ambient conditions for methane oxidation (Gebert et al 2003;Scheutz et al 2009;Gebert, Streese-Kleeberg, et al 2011;Röwer et al 2011). Good results can be expected from soils with pH values between 5.5 and 8.5, organic content between 2 and 4%, a salinity below 4 mS cm −1 and an air capacity of least 14%.…”

Methane oxidation potential of boreal landfill cover materials: The governing factors and enhancement by nutrient manipulation

“…The cover material sample was sieved and 8-12 g of the fraction of <2 mm was incubated in a 120 mL glass bottle with 7% CH 4 (v/v; Aga Ltd. Finland) in the headspace. The initial concentration of 7% CH 4 corresponded to the range of 5-10% CH 4 (v/v) often used in CH 4 oxidation experiments of landfill soil (Albanna and Fernandes, 2009;Einola et al, 2007;Röwer et al, 2011;Wang et al, 2011). The ratio of O 2 /CH 4 in the incubation bottles was approximately 4:1, which was sufficient to support complete aerobic oxidation of CH 4 and respiratory activities of heterotrophic bacteria (Chi et al, 2012).…”

“…These soil covers contain methanotrophs, naturally occurring bacteria, that utilise CH 4 as a sole source of carbon and energy and oxidise it to carbon dioxide (CO 2 ), water and new biomass (Hanson and Hanson, 1996). CH 4 oxidation potential (MOP) of landfill cover material is affected by several factors, including pH, moisture and organic matter contents of the soil, nutrient availability (nitrogen, phosphorus) and physical properties enabling gas diffusion (Einola et al, 2007;Huber-Humer et al, 2011Röwer et al, 2011;Wang et al, 2011). When the cover structure is particularly designed for supporting CH 4 oxidation, such as intermediate covers of active landfills and final covers of closed landfills, some of the parameters can be optimised for methanotrophs via material selection.…”