Which nutrient is commonly limited in wastewater treatment to control algal blooms?

Phosphorus is the nutrient that is commonly limited in wastewater treatment to control algal blooms. Algal blooms occur when there is an excessive growth of algae in water bodies, often driven by an overabundance of nutrients, particularly phosphorus and nitrogen. However, phosphorus is frequently the limiting nutrient in freshwater systems, meaning that when its levels are elevated, it can lead to rapid algal growth.

Wastewater treatment processes often aim to reduce phosphorus levels to mitigate the risk of these blooms, as high concentrations can disrupt aquatic ecosystems, reduce oxygen levels, and negatively affect water quality. By implementing strategies to limit phosphorus discharge, facilities can better manage the nutrient balance in receiving waters, thereby minimizing the potential for algal blooms and their associated environmental impacts.

In contrast, nitrogen can also contribute to algal blooms, but phosphorus is typically the specific nutrient that is controlled in many treatment processes to address these issues in freshwater lakes and rivers. Other nutrients such as potassium and calcium do not have the same direct influence on algal growth in this context.