Performance of ANAMMOX-EGSB reactor

The nitrogen pollution has caused serious environmental problems. The main aims of the present study were to remove the nitrogen from wastewater through ANAMMOX (ANaerobic AMMonium OXidation) process, and let the effluent meet the discharge standard which was significant and advance in the field of ANAMMOX application which was also very important to the environmental protection and water recycling. This study reports the performance of ANAMMOX-EGSB (Expanded Granular Sludge Bed) reactor after feeding with synthetic wastewater. The results showed that the effluent ammonium concentration was 11.90 mg N/L and the nitrogen remove efficiency (NRE) reached up to 94.68% when the volumetric nitrogen loading rate (NLR) and volumetric nitrogen removal rate (NRR) were as high as 27.31 and 25.86 kg N/(m3·d), respectively. The effluent ammonium concentration meets the Chinese integrated wastewater discharge standard (GB8978-1996) in which the ammonium concentration should be lower than 15 mg N/L. The maximum ammonium, nitrite and nitrogen conversion rates (qmax) by the ANAMMOX granular sludge in the reactor were 907.13, 841.76, 1810.10 mg N/(g VSS·d) and half saturation constants (KS) were 2.69, 0.44, 3.11 mg N/L, respectively.

Research highlights
► Anammox-EGSB reactor was used in this study which possessed high efficiency and low operational cost.
► The ANAMMOX-EGSB reactor has excellent performance to meet discharge standard and has good adaptability to the substrate concentrations.
► The ANAMMOX granular sludge has high specific substrate conversion rates and great substrate affinity, these properties ensure the discharged wastewater meet the discharge standard and are very helpful for the water recycling.