Abstract:

In order to investigate the effect of microaerobic biological nitrogen removal under the conditions of different carbon-nitrogen ratio(C/N) of municipal wastewater, the external aeration coupled with backflow oxygen supply microaerobic sludge reactor was involved. The result showed that under the condition of concentration of NH₄⁺-N 60 mg/L and the C/N ≥ 5, the effluent NH₄⁺-N and TN concentrations lower than 6 mg/L and 9 mg/L respectively. As the C/N increased, the protein and polysaccharide content of the extracellular polymer of the sludge, the particle size of the granular sludge all showed a tendency to increase first and then decrease. When C/N was 5, the sludge achieved optimal settlement performance and granulation degree, round shape and specification, compact structure as well. The analysis of the flora structure showed that autotrophic denitrifying bacteria and anammox bacteria had significant effect when C/N was low, but anammox bacteria was gradually eliminated with the increase of C/N, and the main denitrification function was played by heterotrophic denitrifying bacteria. When the C/N < 5, the abundance of autotrophic denitrifying bacteria and anammox bacteria reached 0.55% and 1.19%, and the synergistic symbiosis relationship of the flora was close, and the optimal removal performance was achieved when C/N was 5. In addition, when the C/N>5, the abundance of anammox bacteria was 0.03%.

Key words: C/N, municipal wastewater, microaerobic, granular sludge, high throughput

摘要：

为了考察城市污水不同碳氮比（C/N）下微氧生物脱氮的效果，采用外曝气耦合回流供氧微氧污泥反应器处理城市污水，结果显示，NH₄⁺-N质量浓度为60 mg/L，C/N ≥ 5时，出水NH₄⁺-N、TN分别低于6、9 mg/L；随着C/N的升高，污泥胞外聚合物的蛋白和多糖含量、颗粒污泥粒径均出现先升高后降低的趋势，在C/N=5时达到最优的沉降性能和颗粒化程度，形状规格圆整，结构密实。菌群结构分析表明，在低C/N时自养反硝化菌和厌氧氨氧化菌作用显著，随着C/N的升高，厌氧氨氧化菌逐渐被淘汰，脱氮中起到主要作用的是异养反硝化菌。C/N < 5时自养反硝化菌和厌氧氨氧化菌丰度达到0.55%和1.19%，在C/N=5时菌群协同共生关系紧密，达到最优去除性能，C/N>5时，厌氧氨氧化菌丰度为0.03%。

关键词: C/N, 城市污水, 微氧, 颗粒污泥, 高通量

CLC Number: 

• X703