When is digester decant typically returned to the liquid stream?

Digester decant is typically returned to the liquid stream after influent flow monitoring to ensure that the system is operating efficiently and effectively. This stage is crucial because it allows operators to assess the overall flow rates and the characteristics of the incoming wastewater. By focusing on influent flow monitoring, operators can decide the optimal time to reintroduce decant, aligning with treatment goals and ensuring that the biological processes within the treatment plant are not disrupted.

Returning digester decant involves consideration of the flow rate being treated, allowing for adjustments to be made if necessary to prevent overloading the system. This practice helps maintain the balance between incoming flows and the capacity of the treatment processes, ensuring that treatment can proceed without interruptions.

In contrast, the other options, such as solids measurement, DO concentration checks, and pH stabilization, while important for overall operation and monitoring of the wastewater treatment process, do not specifically dictate the timing for returning digester decant. These parameters assist in evaluating the condition of the treatment system but do not directly correlate with the appropriate timing for returning digester decant to the liquid stream.