Anammox granules formation and performance in a submerged anaerobic membrane bioreactor

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2014-10, Vol.254, p.9-16
• Main Authors: Li, Ziyin, Xu, Xiaochen, Shao, Bing, Zhang, ShuShen, Yang, FengLin
• Format: Article
• Language: English
• Subjects: Anammox; Biodegradation kinetics; Granules; Membrane fouling; SAnMBR
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2014.04.068

•Anammox granules were achieved by selecting a proper shear stress in the SAnMBR.•The granules reached an influent TN of 4.1g/L with TN removal efficiency of 88%.•The formed Anammox granules reached a doubling time of around 6.9days.•NO2−-N degradation kinetics of Anammox biomass was obtained.•Membrane operation circle prolonged with granule size growing from 287 to 896μm. Anaerobic ammonium oxidation (Anammox) granules with the maximum specific Anammox activity (SAA) of 2.14kgN/kgVSS d, the short doubling time of 6.9days and the maximum endurable NO2−-N concentration of 130mg/L were successfully formed in a continuously fed and completely mixing submerged anaerobic membrane bioreactor (SAnMBR). With specific input power ranging from 0.08 to 0.02kW/m3, mean particle size (volume-weighted mean) of the Anammox flocs did not change a lot. With a specific input power of 0.003kW/m3, the mean particle size increased rapidly from 180μm of the flocs to 863μm of the formed granules in 90days. With maximum influent total nitrogen (TN) up to 4.1g/L, a stable nitrogen removal efficiency of 88% was accomplished by the formed granules. The nitrite degradation kinetics was also investigated and it showed that the formed Anammox granules reached its maximum activity at 30mgNO2−-N/L but was strongly inhibited at 150mg NO2−-N/L. With granule size increasing from 287 to 896μm, the membrane operation circle prolonged by 2–2.3 times due to the relief of membrane fouling. The cultivated Anammox granules with high activity and shock resistance capacity, fast growth rate and relieved membrane fouling shows the appealing potential of the Anammox-SAnMBR in treating high-strength nitrogen wastewaters.