碳氮比对SBR系统硝化过程及EPS三维荧光光谱特性的影响

以人工模拟废水为研究对象，采用4组间歇式活性污泥（SBR）反应器（R₀、R₅、R₁₀和R₁₅），探究了硝化过程中碳氮比（C/N）对NH{}_{\mathrm{4}}^{+}-N去除和胞外聚合物（EPS）含量的影响。同时采用三维荧光光谱技术（3D-EEM）结合积分区域法（FRI），分析进出水时EPS各组分所占比例及变化情况。结果表明，4种C/N系统均获得了较高的NH{}_{\mathrm{4}}^{+}-N去除率，且氨氧化速率与C/N呈负相关；C/N升高（0→15），进出水时的EPS及其组分含量随之增大，其中C/N对PS含量影响尤为显著，且硝化过程中多糖（PS）积累。根据荧光区域积分法（FRI）分析，不同C/N条件下EPS各荧光区域强度百分比存在显著差异，其中荧光区域V（腐殖酸类物质，46%~57%）的强度百分比值（P_i,n）最高。此外，蛋白质类物质酪氨酸和色氨酸以及溶解性微生物代谢产物在硝化过程中均被微生物所利用。

Effect of C/N ratio on the performance of nitrification and three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy characterization of extracellular polymeric substances from sequencing batch reactors

This study focused on the effect of C/N ratio on the removal efficiency of NH{}_{\mathrm{4}}^{+}-N and extracellular polymeric substance (EPS) during nitration process by using the sequencing batch reactor (SBR) to treat synthetic wastewater under four C/N ratio conditions (0, 5, 10, 15). Three-dimensional fluorescence spectroscopy (3D-EEM) coupled with fluorescence regional integration (FRI) was used to analyze the constituents of EPS. The results showed that the high removal efficiency of NH{}_{\mathrm{4}}^{+}-N was obtained and the ammoxidation rate was negatively correlated with the C/N ratio. When the C/N ratio increased from 0 to 15, the content of influent and effluent EPS and its components increased, the effect of C/N ratio on PS was significant, and the content of PS was accumulated during nitrification. According to fluorescence region integral (FRI) analysis, there was remarkable difference in the fluorescence response percentage of EPS for different C/N ratio , and region V(humic acid substance, 46%—57%) was the dominant fraction in EPS under different C/N conditions. In addition, the protein-like substance tyrosine and tryptophan, and soluble microbial by-product were utilized during nitrification.