Study on the performance of the hybrid anammox reactor for biological nitrogen removal
复合式厌氧氨氧化反应器脱氮性能研究

A hybrid reactor for anaerobic ammonia oxidation (anammox) process was developed which combined a fixed-bed using non-woven fabrics as biomass carrier with a slow speed agitated bed. The performance of higher biomass retention was obtained in the reactor, and the anammox microorganism in a loose flocculating structure before inoculation formed rapidly into granules. The nitrogen removal ability of the reactor increased obviously in the short term, and the start-up time of the reactor shortened greatly. Only in 38 days, the total nitrogen removal rate (TNRR) reached 1.9 kg·m-3·d-1 and then doubled to 3.8 kg·m-3·d-1 within 17 days. During 180 operating days, a maximum TNRR of 6.6 kg·m-3·d-1 was obtained, and the specific anammox activity (SAA) maintained basically in 0.32 kg·kg-1·d-1. The testing results of size distribution and SEM observation confirmed that anammox sludge granulation process can be greatly enhanced in the mechanical stirred reactor at a lower rotating speed. The anammox bacteria content in the microorganism sludge was about 70%, determined by situ hybridization (FISH) analysis method.