What does a brown foam on the surface of an aeration tank indicate?

A brown foam on the surface of an aeration tank typically indicates a high solids concentration in the wastewater being treated. This phenomenon occurs due to an abundance of microorganisms and organic matter that can lead to the formation of foam during the aeration process. In treatment systems, particularly those utilizing activated sludge processes, excessive organic loading or a higher concentration of suspended solids can result in the production of foam that appears brown due to the presence of biomass.

While foam can be influenced by factors such as oxygen levels, temperature, and chemical conditions, the specific presence of brown foam mainly signals that the solids content is significant, which can affect both the treatment efficiency and the overall operation of the aeration tank. Monitoring this foam is critical for operators to manage wastewater treatment processes effectively.