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One Problem, Many Causes – An Investigative Look at the Underlying Causes of Digester Foaming at a Dallas Wastewater Utility

One Problem, Many Causes – An Investigative Look at the Underlying Causes of Digester Foaming at a Dallas Wastewater Utility

Shimada, Toshio, Thomas Foster, Eva Gorgi, Krishna Pagilla, and Rodolfo Kilian
Published In: 
Water Environment &Technology,  
June 2014
Foaming in anaerobic digesters is a common problem for many water resource recovery facilities. While a small amount of foam in anaerobic digesters is normal and typically goes unnoticed, severe foaming can cause operations and maintenance problems such as clogging of gas handling equipment, tilting floating covers, and foam spills. The Dallas Water Utilities (DWU) Southside Wastewater Treatment Plant has experienced recurring foaming events for several years. These foaming events have resulted in such problems as foam intrusion into the gas collection system and challenges in digester mixing. In addition, while DWU staff implemented intermittent digester mixing to reduce foaming, this has resulted in less-than-optimal mixing and reduced overall system performance. As a result, a study was conducted to determine the causes of foaming and to evaluate alternatives for foam mitigation and control. This study provided multiple solutions to prevent or decrease the severity of digester foaming events.
​Shimada, T., Foster, T., Gorgi, E., Pagilla, K., Kilian, R. "One Problem, Many Causes: An investigative Look at Underlying Causes for Digester Foaming at a Dallas Wastewater Utility." WE&T. 26(6): 48-53. June 2014.