Keywords: partial nitrification, aeration, SBR, sequencing batch reactors, nitrite, biomass concentration
The influence of aeration rate on partial nitrification in sequencing batch reactor
Partial nitrification was investigated in Sequencing Batch Reactor (SBR) under aeration of 100, 500, 1000 and 1600 ml min−1. The biomass concentration was about 1.7 g l−1. When the ratio of alkalinity (mg l−1) to NH4+ -N (mg l−1) was 7.14 : 1, pH and DO would both increase dramatically after ammonia oxidation finished. Through monitoring and controlling the variation of pH and DO in the reactor, a stable partial nitrification process could be maintained. During NH4+-N oxidation the fluctuation range of DO was 0.09∼3.70 mg l−1. The NH4+-N removal efficiency and NO4−-N accumulation rate were higher than 97.9% and 99.1%, respectively.