What is the purpose of anaerobic selectors in wastewater treatment regarding phosphorus?

The function of anaerobic selectors in wastewater treatment is primarily to enhance phosphorus release, making the option that addresses this purpose the most relevant. Anaerobic selectors create an environment where phosphorus-accumulating organisms (PAOs) can thrive by promoting conditions that favor their growth. In the absence of oxygen, these microorganisms can efficiently uptake organic matter and subsequently release stored phosphorus during the treatment process, which is essential for effective phosphorus removal.

While controlling sludge quality is an important aspect of wastewater treatment, it is not the primary role of anaerobic selectors with respect to phosphorus management. Instead, the correct answer highlights the significance of PAOs in enhancing phosphorus release, which is crucial for optimizing treatment efficiency and meeting regulatory standards regarding nutrient discharge.