Influence of sampling strategies on the estimated nitrous oxide emission from wastewater treatment plants.

In the last few years, the emission of nitrous oxide from wastewater treatment plants has become a topic of increased interest, given its considerable impact on the overall climate footprint of wastewater treatment plants. Various sampling strategies to estimate nitrous oxide emission from wastewater treatment plants have been applied in different studies. The present study addresses the influence of sampling strategies on the estimated emission by analysing the variability of an extensive dataset of nitrous oxide emissions resulting from a long-term online monitoring campaign at a full-scale municipal wastewater treatment plant. It is shown that short-term sampling is inadequate to accurately estimate the average nitrous oxide emissions from a particular wastewater treatment plant, while online monitoring is indispensable to capture the short-term variability (diurnal dynamics).