Application of combined process of partial nitritation - anammox using a rotating biological contactor (PARBC) to treat ammonium-rich wastewater

Abstract

Combining the partial Nitritation and Anammox using a rotating biological contactor (PARBC) to remove the ammonium in wastewater was evaluated in this study. The accumulation of Anammox bacteria on the carrier easily obtained after 5 days operating of sequence batch with synthetic wastewater. Then AOB biomass cultivated in PARBC to complete the process of combining two bacteria in the same reactor for completely autotrophic nitrogen removal. After 60 batches of the operation, highest nitrogen removal rate reached 0.33 kg N/m3.d with nitrogen removal efficiency is 90% at a concentration of ammonium input of 250 mg N/L. The specific Anammox activity (SAA) of biofilm and suspended sludge in the tank is determined to be 0.298 gN-N2/gVSS/day and 0.0041 gN-N2/gVSS/day, respectively. Moreover, the suspended sludge concentration is 17.765 mg MLSS/L. This result showed that Anammox bacteria adapt and grow on the rotating biological carrier; otherwise Anammox bacteria hardly develop in the form of suspended sludge in the tank. This study shows that the PARBCR has great potential to effectively removing ammonium from wastewater with the short startup time.