What change should an operator implement to maintain optimum organic loading in the given scenario?

To maintain optimum organic loading, the operator may decide to take a tank out of service. This action effectively reduces the overall treatment capacity of the system, allowing for better management of the organic load during periods of increased influent flow or strength. By doing so, the operator can ensure that the remaining active tanks are not overwhelmed, thus maintaining the proper balance of microorganisms to the organic matter being treated.

When the organic loading is too high, it can lead to several issues, such as decreased treatment efficiency, poor effluent quality, and potential disruptions to the biological processes within the tanks. Taking a tank out of service helps alleviate excess load, allowing the system to operate more effectively with the remaining capacity. It’s a strategic decision to ensure that the treatment works optimally with the available resources.

In contrast, increasing flow would typically increase the organic loading, while decreasing tank volume might result in a reduced surface area for treatment, leading to similar consequences of overloading. Increasing the BOD concentration would have the opposite effect of adding more organic material for the treatment system to process, potentially exacerbating the problem. Thus, removing one of the tanks can be an effective strategy to keep operations within optimal parameters.