Which of the following is a method of nutrient removal in wastewater treatment?

Nitrification is a critical biological process used in wastewater treatment specifically for nutrient removal, particularly for nitrogen. During nitrification, ammonia (NH3) present in the wastewater is converted into nitrate (NO3-) through the action of specific bacteria. This process occurs in two stages: the first involves the oxidation of ammonia to nitrite (NO2-), and the second stage further oxidizes nitrite to nitrate. Removing nitrogen from the wastewater is essential because excess nitrogen can lead to eutrophication in water bodies, which can negatively impact aquatic ecosystems.

In contrast, filtration is primarily used for the physical removal of suspended solids from wastewater and does not specifically target nutrient removal. Screening is a preliminary process that removes large debris and solids, serving more to protect downstream equipment than to affect nutrient levels. Disinfection, while crucial for killing pathogens before effluent discharge, does not concentrate on nutrient reduction but rather on ensuring the treated water is safe for release into the environment or for reuse. Thus, nitrification stands out as the method directly involved in reducing nitrogenous nutrients in the wastewater treatment process.