Ammonia Nitrogen Removal in Attached‐Growth Ponds

Experiments on attached‐growth waste stabilization ponds (AGWSP) are conducted to evaluate the efficiencies, mechanisms, and kinetics of ammonia nitrogen $({\mathrm{NH}}_3‐N)$ removal in AGWSP units. Laboratory‐scale experiments demonstrate that ${\mathrm{NH}}_3$‐N removal is enhanced in the AGWSP units compared to treatment in control units without attached‐growth media. The main mechanism of ${\mathrm{NH}}_3$‐N removal in the AGWSP units is found to be through biological uptake of ${\mathrm{NH}}_3$‐N by the attached and dispersed biomass, while volatilization and nitrification have little effects on ${\mathrm{NH}}_3$‐N removal. Regression equations of various ${\mathrm{NH}}_3$‐N removal rates in AGWSP are developed and validated with data from the pilot‐scale AGWSP experiments and some field‐scale WSP. Applications of the experimental data and of the AGWSP are discussed.