ABSTRACT
From a chemical and biological process-engineering point of view, it is crucial to realize that a sewer network-in addition to being designed and operated as a collector and transport system for wastewater-also includes an overlying sewer atmosphere. This gas phase is particularly abundant in gravity sewer pipes, manholes, and pumping stations, and plays a central role in such phenomena as microbial and chemical processes (redox conditions) of the wastewater, odor nuisance, sewer corrosion, and health impacts. The sewer atmosphere must therefore be focused on in terms of transfer of substances in both directions across the air-water interface as well as for its interactions with processes at the sewer walls and with the surrounding atmosphere.
