Spatial and daily variations of nitrous oxide emissions from biological reactors in a full-scale activated sludge anoxic/oxic process.

Nitrous oxide (NO) is an important greenhouse gas that can be emitted from wastewater treatment plants (WWTPs). Such emissions are reportedly process specific and related to operational parameters. This study was conducted to clarify spatial and daily variations of NO in a full-scale activated sludge anoxic/oxic process that consisted of an anoxic tank and three oxic tanks (oxic-1, oxic-2 and oxic-3), all of which except the final sedimentation tank were fully covered.