Municipal gravity sewers: an unrecognised source of nitrous oxide
Journal article, 2014

Nitrous oxide (N 2 O) is a primary ozone-depleting substance and powerful greenhouse gas. N 2 O emissions from secondary-level wastewater treatment processes are relatively well understood as a result of intensive international research effort in recent times, yet little information exists to date on the role of sewers in wastewater management chain N 2 O dynamics. Here we provide the first detailed assessment of N 2 O levels in the untreated influent (i.e. sewer network effluent) of three large Australian metropolitan wastewater treatment plants. Contrary to current international (IPCC) guidance, results show gravity sewers to be a likely source of N 2 O. Results from the monitoring program revealed hydraulic flow rate as a strong driver for N 2 O generation in gravity sewers, with microbial processes (nitrification and possibly denitrification) implicated as the main processes responsible for its production. Results were also used to develop a presumptive emission factor for N 2 O in the context of municipal gravity sewers. Considering the discrepancy with current IPCC Guidelines, further work is warranted to assess the scale and dynamics of N 2 O production in sewers elsewhere. © 2013 Elsevier B.V.


M Short

University of New South Wales (UNSW)

University of South Australia

A Daikeler

Karlsruhe Institute of Technology (KIT)

University of New South Wales (UNSW)

Gregory Peters

Chalmers, Chemical and Biological Engineering, Chemical Environmental Science

K Mann

University of New South Wales (UNSW)

NJ Ashbolt

United States Environmental Protection Agency

University of New South Wales (UNSW)

RM Stuetz

University of New South Wales (UNSW)

WL Peirson

University of New South Wales (UNSW)

Science of the Total Environment

0048-9697 (ISSN)

Vol. 468-469 211-218

Driving Forces

Sustainable development

Areas of Advance

Building Futures (2010-2018)

Subject Categories

Other Environmental Engineering

Water Treatment

Organic Chemistry



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Latest update

4/9/2018 1