Statistical assessment of dumpsite soil suitability to enhance methane bio-oxidation under interactive influence of substrates and temperature.

ABSTRACT

Biocovers are considered as the most effective and efficient way to treat methane (CH4) emission from dumpsites and landfills. Active methanotrophs in the biocovers play a crucial role in reduction of emissions through microbiological methane oxidation. Several factors affecting methane bio-oxidation (MOX) have been well documented, however, their interactive effect on the oxidation process needs to be explored. Therefore, the present study was undertaken to investigate the suitability of a dumpsite soil to be employed as biocover, under the influence of substrate concentrations (CH4 and O2) and temperature at variable incubation periods. Statistical design matrix of Response Surface Methodology (RSM) revealed that MOX rate up to 69.58µgCH4g-1dwh-1 could be achieved under optimum conditions. MOX was found to be more dependent on CH4 concentration at higher level (30-40%, v/v), in comparison to O2 concentration. However, unlike other studies MOX was found in direct proportionality relationship with temperature within a range of 25-35°C. The results obtained with the dumpsite soil biocover open up a new possibility to provide improved, sustained and environmental friendly systems to control even high CH4 emissions from the waste sector.