Hourly flows from the wastewater source into a commercial ATU should be less than or equal to what parameter?

The correct answer reflects a critical aspect of wastewater treatment system design, particularly regarding the operation of an Aerobic Treatment Unit (ATU). The requirement that hourly flows from the wastewater source into a commercial ATU should not exceed the treatment capacity divided by a specified number ensures that the system has adequate time and capacity to effectively treat incoming waste.

Dividing the treatment capacity by a specific figure allows for the establishment of a safe flow rate that the ATU can handle without overwhelming its treatment processes. In this case, dividing by 24 is generally based on the assumption that the treatment capacity is designed to handle daily flows over a 24-hour period. This means that continuously introducing effluent at a rate higher than that threshold could lead to reduced treatment efficiency, potential system failure, or discharge of inadequately treated wastewater.

The rationale behind using other figures such as 12, 18, or 48 would either indicate a more rapid influx of waste (which could strain the system) or a much slower rate that could lead to inefficiencies in operation. Therefore, ensuring that the hourly flows do not exceed the treatment capacity divided by 24 upholds the operational integrity and success of the ATU in treating wastewater correctly.