Which chemicals are commonly used for phosphorus removal in wastewater treatment?

Phosphorus removal in wastewater treatment is critical for preventing water pollution and eutrophication in receiving water bodies. Iron salts and aluminum salts are the most commonly used chemicals for this purpose due to their effectiveness in binding phosphorus.

When added to wastewater, iron and aluminum salts facilitate the precipitation of phosphate, converting it into insoluble forms that can then be settled out during sedimentation processes. This chemical reaction is essential for reducing the concentration of phosphorus before treated water is discharged or reused. Both ferric chloride (iron salt) and aluminum sulfate, known as alum, are frequently used in treatment plants due to their proven efficacy and efficiency in removing phosphorus from wastewater.

While other chemicals, such as calcium and magnesium salts, can also play a role in phosphorus management, they are not as widely employed specifically for chemical precipitation in wastewater treatment. Sodium bicarbonate and potassium salts are more associated with pH adjustment and nutrient addition, and chlorine and ozone are primarily used for disinfection rather than nutrient removal.