Continuous addition of organic matter (glucose)

at an organic loading to total nitrogen (TN) ratio of 1

was conducted after the UASB-ANAMMOX reactor had reached the stable operation phase.The ANAMMOX-denitrification reactor was successfully started within 35 d under the condition of influent nitrogen loading stably at 0.26 kg.m-3.d-1.The removal efficiencies of ammonia

nitrite

TN and COD were up to 95.3%

99.1%

94.0% and 93.2%

respectively.The average ratio of removed ammonia

removed nitrite and generated nitrate was 1∶1.34∶0.03 at the stable phase.The effect of organic loading shock on the ANAMMOX-denitrification reactor was also investigated.The results demonstrated that the sharp decrease in organic loading had little effect on the reactor

while the sharp increase in organic loading posed notable influence on the reactor.Stable nitrogen removal was achieved after acclimatization

although the effluent quality deteriorated.The effluent quality could be improved by substantially reducing the influent organic loading.The ANAMMOX-denitrification reactor had strong organic loading-resistance.