What is a common effect of improper return treatment in wastewater operations?

Improper return treatment in wastewater operations often leads to the formation of white billowing foam. This phenomenon occurs due to the presence of surfactants, excessive organic matter, or microbial activity that has been impacted by ineffective treatment processes. When wastewater is not properly treated, it can create conditions conducive to the generation of foam, which can be disruptive to operations and may lead to increased odors and the release of volatile compounds.

The presence of foam can hinder the performance of the treatment system by affecting aeration processes and can complicate the management of primary and secondary clarifiers. This problem may also indicate underlying issues with the treatment processes that need to be addressed to restore proper operation. Thus, this choice highlights a significant operational consequence of inadequate return treatment in a wastewater facility.