Use of Flow Regulation in Manhole Odor Control Devices to Reduce Maintenance and Frequency of Media Replacement

Odorous gases emitted from sanitary sewer collection systems contain hydrogen sulfide and other nuisance gases that cause health and safety concerns as well as aesthetics issues for nearby residents. While a systemic approach is needed for addressing odors and gas emissions, one option is to remove odorous compounds prior to release of gases from sewer systems. Previous attempts to use manhole odor control devices have had limited success because the adsorptive media is saturated in the sewer gas and the adsorptive capacity is quickly realized. In this study, a manhole odor control device utilizing pressure regulation to control the flow of gases out of manholes was observed to determine the effectiveness of this device and the ability to reduce the frequency of media replacement. Hydrogen sulfide concentrations were reduced by over 90% and the service life of the media was extended by five months, demonstrating the feasibility of this technology.