Start-up and performance of partial nitritation process using short-term starvation

Abstract

Partial nitritation is a key step toward cost-effective shortcut biological nitrogen removal and anammox process. The current study presents a novel method for achieving partial nitritation at influent ammonium nitrogen concentration of 100 mgNL−1 using short-term starvation and low air flow rate. Mixed activated sludge was introduced into sequencing batch reactor (SBR) under aerobic/anaerobic condition. Variations in the reactor performance, nitrifying bacteria activities, and bacterial community structures were investigated. The results showed that partial nitritation was rapidly achieved, and an average nitrite accumulation rate (NAR) of 878 gNm−3d−1 was observed. The short-term starvation stress on nitrite oxidation bacteria (NOB) activity was relatively higher than that on aerobic ammonium oxidation bacteria (AerAOB) activity. The dominant species of general AerAOB were Nitrosomonas and Nitrosomonadaceae_uncultured, which had better self-adaption to short-term starvation. The moderate starvation could be utilized to achieve nitrite accumulation and nitritation.