2017 journal article

Steam Application to Destroy Foam-Forming Bacteria in Activated Sludge Systems

Journal of Environmental Engineering, 143(5).

By: L. Cubbage, P. Pitt*, A. Stone*, X. He  n & F. Reyes  n

co-author countries: United States of America πŸ‡ΊπŸ‡Έ

Contributors: L. Cubbage, P. Pitt*, A. Stone*, X. He  n & F. Reyes  n

Source: ORCID
Added: January 18, 2019

The use of steam to destroy filamentous foam-forming bacteria was explored as an alternative foam control measure in activated sludge systems. The effects of combinations of steam pressure and exposure time on decreasing filaments, foam potential, and foam stability were evaluated. Statistically significant decreases in mycolata (of nocardioform morphology) abundance were observed at pressures of 275.6, 344.5, 413.4, and 482.3 kPa (40, 50, 60, and 70 psi, respectively) after exposure to steam for 60 min. Lower mycolata abundance levels were obtained at all 482.3-kPa treatments, with the lowest abundance at exposure times of 60 min. Although Microthrix parvicella is less sensitive to the steam treatment than mycolata, slight decreases in Microthrix parvicella abundance were observed at all pressures after 60 min of exposure. Although no drastic changes in foam potential were observed, foam stability was greatly affected by the treatments, leading to nonstable foam formation. The application of steam treatment shows promise in reducing foaming in activated sludge and subsequent downstream solids handling facilities, and is an advantage of thermal hydrolysis processes, which are rapidly gaining acceptance in the industry.