Suitability assessment of dumpsite soil biocover to reduce methane emission from landfills under interactive influence of nutrients.

Biocovers are known for their role as key facilitator to reduce landfill methane (CH) emission on improving microbial methane bio-oxidation. Methanotrophs existing in the aerobic zone of dumped wastes are the only known biological sinks for CH being emitted from the lower anaerobic section of landfill sites and even from the atmosphere. However, their efficacy remains under the influence of landfill environment and biocover characteristics. Therefore, the present study was executed to explore the suitability and efficacy of dumpsite soil as biocover to achieve enhanced methane bio-oxidation under the interactive influence of nutrients, carbon source, and environmental factors using statistical-mathematical models. The Placket-Burman design (PBD) was employed to identify the significant factors out of 07 tested factors having considerable impact on CH bio-oxidation. The normal plot and Student's t test of PBD indicated that ammonical nitrogen (NH-N), nitrate nitrogen (NO-N), methane (CH), and copper (Cu) concentration were found significant. A three-level Box-Behnken design (BBD) was further applied to optimize the significant factors identified from PBD. The BBD results revealed that interactive interaction of CH with NH-N and NO-N affected the CH bio-oxidation significantly. The sequential statistical approach predicted that maximum CH bio-oxidation of 27.32 μg CH h could be achieved with CH (35%), NO-N (250 μg g), NH+-N (25 μg g), and Cu (50 mg g) concentration. Conclusively, waste dumpsite soil could be a good alternative over conventional soil cover to improve CH bio-oxidation and lessen the emission of greenhouse gas from waste sector.