Preliminary Insights into Emissions of Nitrous Oxide Correlated with Methane from Waste Landfills

Abstract

Landfills are significant sources of greenhouse gases (GHG), including methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Traditionally, N2O emissions have been disregarded due to assumed negligible levels. This study investigates N2O generation in simulated landfills under anaerobic and passive aeration conditions. Laboratory columns were filled with a mixture of simulated waste, mimicking real waste composition in Thailand. The experiment ran for 60 days. The results revealed a positive correlation between N2O and CH4 fluxes in the anaerobic column, suggesting N2O production might occur even without oxygen. This challenges the current understanding and necessitates including N2O in future assessments of GHG emissions from anaerobic landfills. However, the findings require further validation through extended experiments with more data collection. The contrasting negative correlation observed in the passive column highlights the complexity of factors influencing N2O production. Further investigation into microniche formation and methane flux analysis is recommended. Additionally, identifying the microbial communities and nitrogen losses within the system is crucial for a comprehensive understanding of N2O generation. This study provides preliminary insights into N2O emissions from landfills and emphasizes the need for further research to refine our understanding and improve the accuracy of landfill-related GHG emission estimations.