High effectiveness is one of the most attractive advantages of the anaerobic ammonium oxidation (anammox) process for nitrogen removal from ammonium-rich wastewater. Granulation is considered to play a vital role in development of high-load bioreactors. The hydraulic retention time (HRT) of the 1.1 L anammox EGSB (expanded-granular sludge bed) reactor was progressively shortened from 6.9 h to 0.30 h; while the influent nitrite concentration was fixed at 360 mg·L-1 and the effluent recycling was maintained at 0.5 constantly. A super high nitrogen removal rate

50.75 kg·m-3·d-1 was recorded

which was 2 times of the highest value reported before. Granulation of the anammox microorganisms occurred in the high-load anammox EGSB reactor. The average diameter of the high-load anammox granules was （2.51±0.91）mm and the specific anammox activity reached 1.899 kg·(g VSS）-1·d-1. The extracellular polymers (ECP) content was 143.00 mg·（g VSS）-1

which was amazingly high when compared to heterotrophic microbial granules. The extracellular proteins increased at a higher rate along with the increase of hydrodynamic shear stress

resulting in over-production of extracellular proteins. Thus the stability of the anammox granules decreased and sludge washout became inevitable.