Enhanced nitrogen removal from ammonium-rich wastewater containing high organic contents by coupling with novel high-rate ANAMMOX granules addition

• The novel SBA-ANAMMOX process was quantified in SBR exposed to high organic contents.
• The nitrogen removal of SBR under high organic conditions was enhanced using SBA-ANAMMOX process.
• ANAMMOX dominated in nitrite competition under the high organic conditions with SBA.
• Sulfate reduction emerged as an important process for utilization of organic matter.
• Simultaneous removal of nitrogen compounds and organic matter was possible via SBA-ANAMMOX.

The ANAMMOX process with sequential biocatalyst addition (SBA-ANAMMOX process) was developed in sequencing batch reactor (SBR) to enhance nitrogen removal from ammonium-rich wastewater containing glucose content up to 800 mgCOD/L. The nitrogen removal performance of the SBR operated with 800 mgCOD/L was significantly enhanced after sequential adding 0.5 gVSS/d of high-rate ANAMMOX granules (HASGs). Kinetics analyses showed that the HASGs possessed high nitrite affinity and strong resistance to organic matter, both of which contributed to the enhancement of autotrophic nitrogen removal. Consequently, ANAMMOX became the dominant reaction to metabolize nitrite under organic conditions; denitrification was limited due to the lack of electron acceptors (nitrite and nitrate); while sulfate reduction emerged as an important process for consumption of organic matter in the SBA-ANAMMOX system. It is suggested that employing the SBA-ANAMMOX process for treatment of organic ammonium-rich wastewater, the simultaneous removal of nitrogenous compounds as well as organic matter was quite possible.