Force Main Odor and Corrosion Control by
SuperOxygenation
by
David Clidence, P.E.,ECO Oxygen Technologies,
3939 Priority Way South Dr. Suite 400 Indianapolis, IN 46240
Phone: 317-706-6487 Fax: 317-816-0940
100 Words:
Like many cities, Knoxville has a force main that was sized for a projected level of development that has not yet been realized. Consequently, the Forks of the River force main developed ideal conditions for H2S generation, often upwards of 800-1000 ppm at the discharge. On the city's quest for a new and cost-effective odor control method, they came upon ECO2's SuperOxygenation Technology. The installation of the system resulted in significant annual O&M savings and better results in H2S reduction than with the previously used traditional chemical.
300 Word Abstract:
The collection systemin the City of Knoxvilleis a complex system of lift stations and mains covering 108 square milesto serve 64,000 customers. Like many cities, Knoxville has a force main that was sized for a projected level of development that has not yet been realized. Consequently, the Forks of the River force main developed ideal conditions for H2S generation, often upwards of 800-1000 ppm at the discharge. The City sought new methods for preventive treatment to reduce the odors.
The root cause of most odor problems associated with wastewater is the presence of naturally created malodorous gases. This problem is exacerbated in long force mains due to high microbial oxygen uptake rates, long detention times, and low dissolved oxygen (D.O.) levels. These anaerobic conditions produce significant amounts of hydrogen sulfide (H2S) which is both odorous and highly corrosive. Since anaerobic conditions are precursors to H2S formation, a logical solution to H2S control is to induce aerobic conditions. SuperOxygenation is a process to sustain aerobic conditions by using an ECO2 “Speece” Cone to dissolve pure oxygen into wastewater to prevent the formation of H2S.
Two ECO2 SuperOxygenation systems were installed on the Forks of the River force main. Performance data shows that the systemsuccessfully reduced hydrogen sulfide gas at the force main discharge to non-detectable levels. TheECO2 system’s capital and annual operating costsresult in a threeyear payback versus alternative chemical treatment.
The presentation will give background information on the root cause of odor and corrosion based on the example of the case study in Knoxville, TN. The concept of preventing odor and corrosion by SuperOxygenation is explained and compared to traditional odor control chemical treatment.