Study on start-up and running of ANAMMOX reactor

Using ANAMMOX biomass cultivated and anaerobic granular activated sludge(ratio of 2∶1)as inoculum,the ANAMMOX reactor was started up successfully.Factors that could affect the operation of ANAMMOX reactor,such as volumetric loading and dissolved oxygen refluxing,were investigated.The result shows that ANAMMOX reactor is resilient when undergoing step changes of volumetric loading.When average volumetric loading of NH+4-N and TN was increased respectively from 32.78 mg/(L·d) and 78.62 mg/(L·d) to 78.55 mg/(L·d) and 180.16 mg/(L·d),the average removal rates of NH+4-N and TN dropped gradually from 71.20% and 66.65%,and then back to 62.11% and 56.59%.Because of the influent with dissolved oxygen,the actual ratio of removed NH+4-N and NO-2-N(1∶1.27) was higer than the theoretical ratio(1∶1.32).Aerobic ammonia oxidation reaction and anaerobic ammonia oxidation reaction both occurred in the ANAMMOX reactor,with anaerobic ammonia oxidation reaction being the main reaction.