Improve nitrogen removal of the biofilm single-stage PN/A process by optimizing the intermittent aeration strategy
Linh-Thy Le, Long D. Nghiem, Xuan‐Thanh Bui, Deokjin Jahng
Abstract
This study demonstrated a novel technique to achieve partial nitritation/anammox (PN/A) to treat inorganic low-strength wastewater by using a 10 L continuous reactor equipped with fiber carriers. Aeration control was the key factor in single-state PN/A performance stability under oxygen-limiting conditions. Intermittent aeration was successfully adapted in this study to achieve over 80% nitrogen removal at the nitrogen loading rate of 0.12–0.16 kg N m−3 d−1. The nitrite-oxidizing bacteria activities were inhibited by intermittent aeration due to the alternate between aerobic to anoxic conditions. Ammonium-oxidizing bacteria (AOB) and anammox bacteria could be symbiotically supported within the biofilm with a specific activity of anammox bacteria that was 1.5 times higher than that of AOB. The biomass was efficiently retained by using fiber carriers. The results obtained from this study could bring the possibility of applying an energy-saving and efficient biofilm single-stage PN/A process in tropical regions.