摘 要

目前，水环境氮素污染日益严重，新型生物脱氮工艺的研发受到了世界各国的关注。单级自养脱氮系统与传统硝化反硝化脱氮工艺相比具有能耗低、脱氮效率高等优点，因此，单级自养脱氮系统逐渐成为学者们研究的热点。

迄今为止，关于单级自养脱氮系统的研究仍主要集中在生物膜和颗粒污泥的研究方面，对于以亚硝化絮状污泥和厌氧氨氧化颗粒污泥为接种污泥的反应体系，其系统中絮状污泥和颗粒污泥各自的脱氮贡献率研究仍有待深入。本研究接种实验室培养的亚硝化絮状污泥和厌氧氨氧化颗粒污泥，在SBR反应器内建立全程曝气的单级自养脱氮系统，研究絮状污泥和颗粒污泥的形态结构变化以及脱氮贡献率，主要研究结论如下：

（1）系统在接种亚硝化絮状污泥和厌氧氨氧化颗粒污泥后，运行稳定，脱氮效果较好。通过调控HRT和DO等方式，成功启动了絮状-颗粒污泥耦合的 SBR 单级自养脱氮系统，系统内氨氮去除负荷为27.77 mgN/(L·h)，总氮去除率为94.5%。由于第34-50周期时，转子流量计发生故障，在此期间，系统脱氮效果受到影响，氨氮开始积累，出水氨氮浓度较高。在更换转子流量计，重新调节好空气流速以后，系统脱氮性能逐渐恢复。在125-175周期内，为了控制出水中亚硝氮的浓度，降低了空气流速，使氨氮的去除受到影响，系统总氮去除率也降低至30%-50%。因此，需要对DO进行有效调控，才能使单级自养脱氮系统达到高效脱氮的目的。

（2）经过一段时间的培养，絮状污泥由第0周期刚接种时的分散、蓬松形态变得聚集、密实，粒径由最初的108.873μm增大至331.449μm；颗粒污泥粒径则1.63mm增大至2.14mm，并且明显可以看出颜色有明显的变化，由接种初期的红褐色逐渐变浅，在颗粒表面形成一层黄褐色的膜。推测该薄膜为亚硝化菌附着在颗粒污泥表面形成，由此构成了有利于厌氧氨氧化过程进行的微环境，让AOB在好氧表层生存，AAOB在缺氧内层生存，最终实现单级自养脱氮。

（3）系统启动初期，反应器内总氮去除率为94.5%。在相同氨氮浓度曝气条件下，启动初期的絮状污泥总氮去除率为10.14%，颗粒污泥总氮去除率为3.90%。反应器内絮状污泥主要发生亚硝化作用，颗粒污泥利用絮状污泥产生的亚硝态氮发生厌氧氨氧化作用，两者共同作用实现全程自养脱氮过程。系统启动成功后，反应器总氮去除率为96.2%。全程曝气条件下絮状污泥和颗粒污泥均表现出较高的总氮去除效率。

（4）絮状污泥经过一段时间的培养，总氮去除率由10.14%提高到89.70%，至少存在80%的厌氧氨氧化脱氮量，自养反硝化比例略微降低，为5%-6%，曝气条件下可能存在1%左右的异养反硝化脱氮。颗粒污泥经过一段时间培养之后，总氮去除率提高到83.2%，曝气条件下自养反硝化脱氮比例由启动初期的7.91%减小到3%，曝气条件下不存在异养反硝化过程。

（5）反应器经过一段时间的启动AOB、NOB、AAOB、DNF等功能菌的数量呈现动态变化。最初，絮状污泥中AOB占据绝对优势地位，在经过121个周期后AOB含量急剧下降，系统内AAOB增多成为优势菌。这可能是由于部分颗粒在曝气条件下解体，厌氧氨氧化菌进入絮状污泥中所导致的。同时在微量曝气条件下，会抑制好氧菌的生长，导致其数量的下降。

关键词：单级自养脱氮，脱氮贡献率，絮状污泥，颗粒污泥

Abstract

At present, the nitrogen pollution of water environment is increasingly serious, research and development of new biological denitrification process by the attention of the countries all over the world. Single-stage autotrophic denitrification system compared with the traditional nitrification and denitrification denitrification process has advantages of low energy consumption and high efficiency of denitrification, as a result, single stage autotrophic denitrification system gradually become hot topics in the study of scholars.

So far, the research on single stage autotrophic denitrification system is still concentrated in the study of biofilm and granular sludge in the nitrosation flocculent sludge granular sludge for the inoculation sludge and anaerobic ammonia oxidation reaction system, the system and granular sludge flocculent sludge denitrification contribution remains to be further research. This study vaccinated lab-grown nitrosation granular sludge flocculent sludge and anaerobic ammonia oxidation, establish worthies aeration in the SBR reactor single-stage autotrophic denitrification system, research and granular sludge flocculent sludge morphology change and denitrification contribution, the main research conclusions are as follows:

system in the inoculated nitrosation flocculent sludge and anaerobic ammonia oxidation of granular sludge, stable running, denitrification effect is better. By regulating the HRT and DO, successfully launched coupled flocculation - granular sludge SBR single-stage autotrophic denitrification system, ammonia nitrogen removal in the system load is 27.77 mgN/h (l.), total nitrogen removal rate was 94.5%. Due to the 34th - 50 cycles, the malfunction of the rotameter during this period, system denitrification effect affected, ammonia nitrogen began to accumulate, effluent ammonia nitrogen concentration is higher. In replacement of the rotor flowmeter, adjust good air flow rate, system denitrification performance gradually restored. In 125-175 period, in order to control the water nitrate nitrogen concentration in central Asia, reduces the air velocity, the ammonia nitrogen removal is affected, the system total nitrogen removal rate is also reduced to 30% 50%. Therefore, we need to DO for effective control, to make the single-stage autotrophic denitrification system to achieve the purpose of efficient denitrification.

(2) after a period of training, flocculent sludge by cycle 0 first vaccination dispersion, fluffy form become gathered, dense, particle size from the original 108.873 μm increases to 331.449 μm; Granular sludge particle size increases 1.63 mm

to 2.14 mm, and obviously you can see a marked change color, early by inoculation of reddish brown becomes shallow gradually, in the particle surface to form a film of tan. Speculated that the thin film of nitrosation bacteria adhere to the surface of granular sludge formation, thus constitutes for anaerobic ammonia oxidation process in micro environment, let the AOB, to survive in aerobic surface AAOB survival in the inner of oxygen and finally realizes the single-stage autotrophic denitrification.

(3) early system start up, the total nitrogen removal rate was 94.5% in the reactor. In the same concentration of ammonia nitrogen aeration condition, the initial total nitrogen removal rate was 10.14%, the flocculent sludge granular sludge total nitrogen removal rate was 3.90%. Flocculent sludge mainly occurs in the reactor and nitrification, and granular sludge using flocculent sludge produced by the nitrate nitrogen in anaerobic ammonia oxidation, the two work together to achieve full autotrophic denitrification process. After the success of the system startup, reactor, the total nitrogen removal rate was 96.2%. All the aeration condition and granular sludge flocculent sludge showed higher total nitrogen removal efficiency.

(4) the cultivation of the flocculent sludge after a period of time, the total nitrogen removal rate from 10.14% to 89.70%, there are at least 80% of the nitrogen amount of anaerobic ammonia oxidation, autotrophic denitrification rate reduced slightly, to 5% - 6%, under the condition of aeration could be around 1% of the heterotrophic denitrifying denitrification. Granular sludge cultivation over a period of time, the total nitrogen removal rate increased to 83.2%, under the condition of aeration autotrophic denitrification denitrification rate reduce to 3%, from 7.91% the initial does not exist under the condition of aeration heterotrophic denitrifying process.

（5）After a period of time the number of reactor startup AOB, NOB, AAOB, DNF features such bacteria are dynamic. Initially, flocculent sludge AOB occupy an absolutely dominant position, AOB content sharply after 121 cycles, the system AAOB increase become dominant bacteria. This may be due to partial dissolution of the particles in the aeration, anammox bacteria into the flocculent sludge caused. Meanwhile in micro aeration, it will inhibit the growth of aerobic bacteria, leading to its decline in the number.

Key Words: Single stage autotrophic nitrogen removal; nitrogen removal contribution; flocculent sludge; granule sludge

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