本论文主要研究了在不同运行方式和运行条件下好氧颗粒污泥系统的生物脱氮特性以及采用好氧颗粒污泥实现快速脱氮，主要研究结果如下。（1）采用交变负荷和缩短沉淀时间的方法培养好氧颗粒污泥，经过75天的运行，反应器实现完全颗粒化，完全颗粒化之后，反应器中的污泥浓度和颗粒平均粒径分别达到6.3 g/L和876 μm。批式实验结果显示同一反应器中颗粒污泥的硝化速率和反硝化速率均高于絮体污泥。（2）颗粒SBR在常规负荷1 kgCOD/m3•d的条件下连续运行90天，反应器连续运行40天后，好氧颗粒污泥的表面出现丝状菌过度生长的情况，并在颗粒反应器中形成黑色的真菌颗粒。在产生真菌颗粒的初始阶段，少量的真菌颗粒对反应器有机物降解和生物脱氮没有太大影响，但是当反应器在运行到第85天时，好氧颗粒完全消失，好氧颗粒污泥全部转变成黑色的真菌颗粒。黑色真菌颗粒主要由黑色的丝状微生物在颗粒黑色的晶核外面相互缠绕所形成。三维荧光结果显示好氧颗粒和真菌颗粒的EPS组分没有太大的区别，但是同一反应器中真菌颗粒的EPS含量高于好氧颗粒污泥。（3）好氧颗粒污泥和真菌颗粒的比好氧速率（SOUR）H和（SOUR）N分别为12.83，7.3和2.07，0.71 mgO2/gSS•h，随着真菌颗粒的产生，反应器对COD和NH4-N的去除率逐渐从初始的90.4–96.5% 和 99.5% 下降到71.8% 和 32.9%，根据丝状菌的生长特性，推测真菌颗粒的产生主要是由于反应器长期在常规负荷和较长的泥龄条件下运行所导致的，如何控制颗粒SBR中真菌颗粒的产生还需要进一步的研究。（4）在颗粒SBR的缺氧过程中研究四种不同的混合形式对好氧颗粒反硝化的能力及特性。批式实验结果显示好氧颗粒污泥在初始COD/NO3-N比值为4时，在静置条件下的反硝化速率为0.104 kgNOx-N/m3•d，但是在摇床上震荡混合时，反硝化速率达到0.168 kgNOx-N/m3•d，这一结果充分说明混合条件对好氧颗粒反硝化速率有较大影响。采用好氧颗粒污泥并以葡萄糖作为电子供体进行反硝化且初始COD/NO3-N比值分别为2，4，6和8时，在充分混合条件下的反硝化速率分别达到0.106，0.168，0.501和0.68 kg NOx-N/m3•d，在60分钟的反硝化时间段内，对NO3-N的去除率分别达到15%，39%，64.9%和93.9%。（5）颗粒SBR在完成硝化反应后停止曝气并加入葡萄糖使初始COD/NO3-N为8，反硝化阶段采用间歇空气混合方式时，反硝化速率最低，仅为0.091 kgNOx-N/m3•d，且对NO3-N的去除率较低，这主要是由于反硝化过程中高DO浓度和不充分的混合所导致的。（6）当采用充入氮气的方式进行混合时，在1小时的反应期内，反硝化速率和NO3-N去除率分别达到0.7 kgNOx-N/m3•d和97%。颗粒反应器的周期运行结果表明，采用上清液回流的方式进行混合时，2小时反应时间内的反硝化速率和NO3-N去除率分别达到0.288 kgNOx-N/m3•d和98.5%，但是在这种混合方式条件下，反硝化产生的氮气导致反应器中部分颗粒污泥上浮，使得反应器在这种运行条件下不能连续稳定的运行，不利于颗粒污泥的稳定，反硝化过程中，反应器底部和上部的颗粒污泥粒径分别为428 μm 和701 μm，在10天的连续运行条件下，NH4-N去除率从99.1%下降到42%，污泥浓度从初始的5.9 g/L下降到2.5 g/L。（7）在缺氧过程中采用机械搅拌混合形式时，在连续运行条件下对好氧颗粒污泥的稳定性没有太大影响，当进水TN和COD保持在55和320 mg/L时，在50天的连续运行时间内，平均反硝化速率、总氮去除率和脱氮速率分别达到0.64 kgNOx-N/m3•d，97.7% 和0.255 kgN /m3•d。（8）实验对比考察了颗粒SBR在完全好氧，好氧/缺氧，缺氧/好氧以及批式进水缺氧/好氧交替运行四种不同运行方式下的脱氮能力，四种不同运行方式下的TN去除率分别为48.9%，52.4%，55.8%和90.5%，这一结果说明前三种运行方式对颗粒SBR生物脱氮影响较小，同时说明第四种运行方式能有效的提高TN去除。在完全好氧运行且进水C/N为5的条件下，研究了不同DO浓度对颗粒脱氮的影响，结果显示在实验选取的3个DO浓度1.5，3.0和5.7 mg/L条件下，完全硝化的时间分别为510，280和160分钟，同时颗粒SBR对TN的去除率分别为78.9%，48.9%和34.8%，DO浓度对同步硝化反硝化效率和TN去除有较大影响。颗粒反应器在批式进水条件下，分别考察了进水次数n对TN去除的影响，随着进水次数从1依次增加到4，TN去除率分别为54.3%，78%，86.4%和91.4%。（9）反应器在批式进水条件下连续运行90天，TN去除率稳定在88.7–92.6%，此外，用pH和DO的拐点来表征四个好氧过程的反应节点，同时用pH的拐点表征四个反硝化的节点，通过连续监测pH和DO的拐点，将反应器周期从360分钟缩短至207分钟，缩短运行时间后对TN的去除没有太大的影响，TN去除率和脱氮负荷分别高达89.7–92.4%和0.27 kgN/m3•d，此脱氮速率高于类似运行方式和条件下的絮体污泥系统。经过90天的连续运行，颗粒表面主要以球菌为主，颗粒污泥在长期运行条件下能保持稳定。

This study focused on the study of biological nitrogen removal characteristics of granular SBR under different operational strategies and conditions. Meanwhile, the high-rate nitrogen removal was achieved in this experiment. The main results were showed as below.(1) Laboratory experiments were conducted to investigate the transformation and performance of a granular sequence batch reactor (SBR) under the conventional organic loading rate (OLR) condition. Aerobic granules were successfully cultivated in a SBR by means of alternative feeding load combined with reducing settling time after 75 days operational period. The mixed liquid suspended solids (MLSS) and average size reached 6.3 g/L and 876 μm, respectively. The experimental results showed that both specific nitrification and denitrification rates of granules were higher than conventional activated sludge in same granular SBR. (2) The black fungal granules were present in reactor because of the filamentous overgrowth on the surface of aerobic granules after operated for 40 days. A small amount of fungal granules had no obvious effect on the performance of granular SBR in the initial operational stage. However, aerobic granules completely vanished and fungal granules eventually became the dominant species in subsequent 85 days operation after granulation. The surface of the fungal granule was primarily formed by fungi-like long black filamentous microorganisms, which tangled together and surrounded black core in the center of fungal granules. The three-dimensional excitation emission matrix (EEM) spectra result showed that the extracellular polymeric substances (EPS) component in both granules had no much difference, whereas the content of EPS in fungal granules was higher than bacterial granules. (3) The (SOUR)H and (SOUR)N of the aerobic granules and fungal granules were 12.83, 7.3 and 2.07, 0.71 mgO2/gSS•h, respectively. Due to their low bioactivity, COD and NH4-N removal efficiencies gradually decreased from 90.4–96.5% and 99.5% to 71.8% and 32.9% while the fungal granules became dominant in the SBR. This result confirmed that the generation of fungal granules in granular SBR had a great impact on nitrogen removal. It was speculated that the generation of fungal in granular SBR was mainly resulted from the conventional organic load and long sludge retention time (SRT). Further investigations were needed to control the overgrowth of fungal micorganism in granular SBR.(4) The characteristic and comparison of the denitrification potential of aerobic granular sludge under four different mixing conditions in lab-scale granular sequence batch reactor was conducted. Batch experimental results showed that the specific denitrification rate (SDR) reached 0.68 and 0.11 kg NOx-N/m3d with and without mixing, respectively. The SDR and NO3-N removal efficiency reached 0.106，0.3，0.501, 0.68 kgNOx-N/m3•d and 15%，39%，64.9%, 93.9% under the initial COD/NO3-N ratios of 2, 4, 6 and 8 conditions in 60 min. (5) The lowest SDR of 0.091 kgNOx-N/m3•d was achieved under intermittent aeration condition, which mainly resulted from the high dissolved oxygen (DO) concentration and poor mixing in denitrification process. (6) The SDR and NOx-N removal efficiency was dramatically improved to 0.7 kg NOx-N/m3•d and 97% under the mixing condition by introducing gaseous nitrogen to reactor during 60 min denitrification process. It was found that the mixture under recycling supernatant liquid condition did not benefit for the stability of granules due to the sludge floating problem in denitrification process, i.e., the average size in the bottom and upper of reactor during denitrification was 428 μm and 701 μm. Under this mixing condition, the NH4-N and MLSS decreased from 99.1% to 42% and 5.9 g/L to 2.5 g/L during 10 days continuous operation period. (7) The mechanical stir had little impact on granules under oxic/anoxic combined with mixing by mechanical stir in anoxic phase operational strategy. When the total nitrogen (TN) and COD were kept at 55 and 320 mg/L in the influent, the SDR, nitrogen removal efficiency and rate reached approximately 0.64 kgNOx-N/m3•d, 97.7% and 0.255 kgN/m3•d in 50 days continuous operation.(8) Four operational strategies were, i.e., oxic, oxic/anoxic, anoxic/oxic and alternating anoxic/oxic combined with the step-feed granular sequence batch reactor (step-feed SBR) operated in laboratory scale to investigate nitrogen removal. The cycle performance demonstrated that the TN removal efficiencies were 48.9%，52.4%，55.8% and 90.5% under four different operational strategies conditions. This result suggested that the first three operational modes had less impact on nitrogen removal and the step-feed mode could effectively enhance the nitrogen removal. Under the complete oxic operational mode and C/N ratio of 5 conditions, the complete nitrification processes were achieved in 510, 280 and 160 min while the DO concentration maintained at 1.5, 3.0 and 5.7 mg/L. Meanwhile, TN removal efficiencies reached 78.9%, 48.9% and 34.8%, respectively. This result showed that the DO concentration had important impact on SND efficiency and nitrogen removal. The nitrogen removal were 54.3%, 78%, 86.4% and 91.4% under the feeding steps of 1, 2, 3 and 4 conditions in granular SBR. The continuous operation results showed that the TN removal efficiencies were 89.7–92.4% in the step-feed mode in 360 min cycle. (9) The pH and DO were used to optimize the process of denitrification and nitrification in the step-feed mode. The optimized operational condition was achieved by shortening the cycle time to 207 min, resulting in a nitrogen removal rate of 0.27 kg N/m3•d, which was much higher than those achieved using activated sludge systems. The dominant community in the aerobic granules was coccus-like bacteria, and filamentous bacteria were hardly found. Granules were well maintained throughout the 90 days of continuous step-feed operation.