Evaluation of nitrous oxide (N2O) emissions during nitrogen removal from urban wastewater in submerged biofilm reactors

Nitrous oxide (N2O) has a greenhouse effect, which is 273 times higher than that of carbon dioxide according to the latest IPCC estimation. Therefore, even relatively small amounts can result in a significant carbon footprint. N2O is emitted during the biological nitrogen removal processes of wastewater treatment. This study evaluates direct N2O emissions during biological nitrification and denitrification in submerged fixed-film reactors using data from the author’s pilot plant experiments. The calculations are based on typical parameters and emission factors but an improved approach for their identification, than the widely used, is applied.