脉冲曝气活性污泥胞外聚合物的产生特性及其与脱氮效率的关系

为探讨脉冲曝气活性污泥胞外聚合物（EPS）的产生特性及其与脱氮效率的关系，研究了在脉冲曝气装置中曝气时间5 min及停曝时间10 min的条件下，松散结合型胞外聚合物（LB-EPS）与紧密结合型胞外聚合物（TB-EPS）的变化规律，并分析EPS与脱氮效率之间的关系。结果表明：脉冲曝气活性污泥LB-EPS的含量低于TB-EPS含量，且随着脉冲驯化的进行，EPS的含量持续增长。三维荧光图谱（3D-EEM）分析表明脉冲曝气的LB-EPS的色氨酸荧光峰产生红移，TB-EPS的色氨酸荧光强度增大，说明了脉冲曝气驯化过程导致了活性污泥胞外聚合物中色氨酸蛋白类物质含量呈增加趋势。对比研究表明：脉冲曝气氨氮（NH4+-N）去除率在80%左右，与连续曝气相近；而总氮（TN）去除率在50%左右，高于连续曝气20%。脉冲曝气下，EPS对于脱氮有抑制作用，EPS与NH4+-N及TN的去除率之间呈负相关的关系，LB-EPS与TN去除率之间负相关；TB-EPS与NH4+-N去除率负相关且关系显著。

Characteristics of extracellular polymeric substances of pulse aerated activated sludge and its relationships with nitrogen removal efficiency

In order to investigate the characteristics of extracellular polymeric substances(EPS) of pulse aerated activated sludge and its relationship with denitrification efficiency. A study between loosely bound EPS (LB-EPS) and tightly bound EPS(TB-EPS) was carried out under the condition of the pulse aeration.Aerobic time was set for 5 min and anoxic time for 10 min.The relationship between EPS and denitrification efficiency was also analyzed. The results showed that the content of LB-EPS was lower than that of TB-EPS and the EPS content kept increasing during the whole pulse aeration acclimation process.Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy showed that the fluorescence intensity of tryptophan in LB-EPS had a red shift and the fluorescence intensity in TB-EPS increases indicating that the content of tryptophan protein had an increasing trend in the EPS of activated sludge with pulse aeration. The removal rate of ammonia nitrogen(NH4+-N) in pulse aeration reactor was about 80%, which was close to that of continuous aeration reactor. However, the removal rate of total nitrogen(TN) was about 50%, nearly 20% higher than that of continuous aeration reactor. EPS has a detrimental effect on denitrification. There was a negative correlation between the EPS content and the removal rate of NH4+-N and TN under pulse aeration condition. The negative correlation that were significant between LB-EPS and the removal rate of TN. The correlation between TB-EPS and the removal rate of NH4+-N was also negative.