Which is true regarding the growth rate of nitrifiers?

The correct answer highlights that the growth rate of nitrifiers decreases as temperatures drop. Nitrifiers, which include bacteria responsible for the process of nitrification, are sensitive to temperature changes. When temperatures are low, their metabolic processes slow down, leading to a decrease in their activity and growth rate.

This relationship is critical in wastewater treatment processes, as the efficiency of nitrification can be significantly affected by temperature fluctuations. Warmer temperatures generally promote increased metabolic rates, resulting in enhanced nitrifier activity, while cooler temperatures can inhibit their growth and function, potentially leading to less effective ammonia oxidation in treatment systems. Understanding this aspect of nitrifiers is essential for optimizing conditions in wastewater treatment facilities to ensure efficient nitrogen removal.