Start up of an anaerobic ammonium oxidation process in an anaerobic sequencing batch reactor

Digested sludge and anaerobic granular sludge were inoculated together in an Anaerobic Sequencing Batch Reactor(ASBR).The Anaerobic Ammonium Oxidation(ANAMMOX)bacteria were domesticated for 160 d with HRT of 24 h,pH of 7.3~8.5,temperature of(35±1)℃,and influent concentrations of NH+4-N and NO-2-N of 120 mg·L-1.Experimental results indicate that the average removal rate of NO-2-N、NH+4-N and TN were 93.2%,95.7% and 86.9%,respectively.The average volume load of the ASBR Anaerobic Ammonia Oxidation reactor was 0.38 kg·m-3·d-1.The effluent pH values from the ANAMMOX reaction process were higher than the influent,and stabilized at about pH 7.74.High rates of anaerobic ammonia oxidation were observed for the small brick red granular sludge produced at the end of the start-up process.