[Kinetic characteristics of high-rate ANAMMOX granules]

The high-rate ANAMMOX granules (HAG) were cultivated in an ANAMMOX upflow anaerobic sludge blanket (UASB) reactor. The kinetic characteristics of the HAG were investigated through batch tests, using flocculent ANAMMOX sludge (FAS) as a control. The results suggested that the specific ANAMMOX activity (SAA) of the HAG reached as high as 2.63 kg x (kg x d)(-1), which was 2.5 times of that of FAS. The half saturation constants for ammonium and nitrite of the HAG were 17 mg x L(-1) and 19 mg x L(-1), respectively, both were lower than those of the FAS. The half inhibition constants of ammonium, free ammonia and nitrite were 11,679,505 and 735 mg x L(-1), respectively, which were far higher than the corresponding values of the FAS. The better kinetic performance of the HAG contributed to the successful competition of substrates under tough conditions, which was helpful for the novel biomass supplementation process for enhancement of the ANAMMOX performance.