【作者】 郭海燕；

【导师】 周集体；

【作者基本信息】 大连理工大学 ， 环境工程， 2005， 博士

【摘要】 依据常规生物脱氮原理,脱氮过程包括将氨氮氧化为硝酸盐氮或亚硝酸盐氮的硝化反应和将硝酸盐氮或亚硝酸盐氮还原为氮气的反硝化反应。硝化反应是一个好氧过程,由自养菌完成;而反硝化反应是一个缺氧过程,由异养菌完成。传统的生物脱氮工艺中,硝化和反硝化是在两个或多个独立的具有不同溶解氧浓度的反应器中进行,或是在时间上造成交替缺氧和好氧环境的同一个反应器中进行。这样的工艺往往存在着需进行硝化液回流或外加有机碳源和补充碱度,运行费用高,占地面积大,投资高等缺点。针对这些问题,本文提出了一种新型的曝气动力循环一体化同时硝化反硝化生物膜反应器用于生活污水的脱氮和脱碳处理,硝化反应和反硝化反应分别在反应器不同分区内完成,利用给氧曝气动力实现硝化液在反应器内的循环。 采用实际生活污水和模拟的生活污水考察了不同运行条件下反应器的脱碳和脱氮效果,优化了运行条件。反应器经过近两年的连续运行,结果表明,一定进水负荷条件下,通过对反应器曝气速率,进水位置,各分区液体循环控制板高度等手段的调节,在单体反应器内同时实现了硝化反应和反硝化反应,并且硝化和反硝化两个反应过程能够达到了良好的平衡状态。在提高反应器有机负荷和总氮负荷的过程中,硝化反应为脱氮过程中的限制步骤。在曝气条件不变的条件下,进水有机负荷的提高会增加异养的好氧菌和自养的硝化菌对DO和其它营养物质的竞争,降低反应器的硝化效果。通过提高曝气速率、降低好氧区和缓冲区液体循环控制板高度的手段可以增加好氧区和缓冲区内混合液溶解氧浓度,降低有机物氧化对硝化作用的影响。在进水有机负荷为0.27～49.53kgCOD/（m³.d）,TN负荷为0.1kgTN/（m³.d）的条件下,保持好氧区和缓冲区DO>2.9mg/L,缺氧区DO<1.5mg/L,反应器对COD和TN的去除率分别为93%和80%,达到了常规A/O工艺的去除效果。 由于硝化反应和反硝化反应在同一处理单元内的同时发生,进水中的有机碳源能够作为反硝化反应的电子供体被有效利用,在进水C/N比为2.7～4的条件下,反应器的反硝化率仍然能够达到83%以上;反硝化反应产生的碱度可以部分补充硝化反应消耗的碱度,在进水碱度为280～450mg/L的条件下,反应器各区pH能够稳定在7.5～8.5之间,为脱氮过程的顺利进行创造了条件。反应器不同分区的污泥都同时具有硝化能力和反硝化能力,但活性明显不同。好氧区和缓冲区由于硝化反应占优势,NH₄⁺-N和碱度浓度低,NO₃^--N浓度高;缺氧区则与之相反,反硝化反应占优势,NH₄⁺-N和碱度浓度高,NO₃^--N浓度低。反应器脱氮是基于宏观上不同分区发生的硝化反应和反硝化反应以及生物膜内部发生的同时硝化和反硝化反应（SND）而实现的。更多还原

【Abstract】 Based on traditional biological nitrogen removal theory, nitrogen removal involves nitrification of ammonia to nitrate or nitrite followed by denitrification of nitrate or nitrite to nitrogen gas. Nitrification is an aerobic process and carried out by the autotrophic microorganisms, whereas denitrification is restricted to anoxic conditions and realized by the heterotrophic microorganisms. For conventional nitrogen removal processes, nitrification and denitrification are carried out in separated tanks with different dissolved oxygen concentration or in a single reactor where aerobic and anoxic conditions are formed sequentially. Such processes usually need the recirculation of nitrified wastewater or the addition of external organic carbon and alkalinity. The investment and operation cost is high, and the land occupied is large. As to these problems, a novel integrated nitrification and denitrification biofilm reactor with liquid circulation driven by aeration is developed and applied as a single treatment unit for carbon and nitrogen removal of domestic wastewater. Nitrification and denitrification are accomplished respectively in the aerobic zone and anoxic zone of the reactor and the energy needed to ensure a good aeration is utilized for the circulation of nitrified wastewater.Simulated and practical domestic wastewater was used to investigate the carbon and nitrogen removal capacity of the reactor under various operation conditions and the operating parameters were optimized. Two years continuous experiment demonstrated that nitrification and denitrification were accomplished simultaneously in the single reactor and good balance between the two reaction processes could be obtained by adjusting the operating parameters as aeration rate, inlet position and baffle height et al. Nitrification had always been the rate-limiting reaction step of the nitrogen removal process when the influent organic carbon and nitrogen loading was enhanced. Under the condition of certain aeration rate, the increased organic carbon loading could strengthen the competition between the aerobic heterotrophs and authotrophic nitrifiers for oxygen and other nutrients and decrease the nitrification efficiency. Increasing the aeration rate and decreasing the baffle height could improve the DO concentration in the aerobic zone and buffering zone and decrease the impact of organic carbon oxidization on nitrification. When the DO concentration in the aerobic zone and buffering zone was kept at above 2.9mg/L and that in the anoxic zone below 1.5mg/L, COD and TN removal efficiencies of the reactor came up to 93% and 80% respectively with the influent organic loading 0.27~0.53kgCOD/(m~3. d) and nitrogen loading 0.1kgTN/(m~3. d). Removal capacity of the reactor is comparative to the A/O nitrogen removal process.Because nitrification and denitrification were achieved in a single reactor, the influent organic carbon components could be effectively utilized as electron donor for denitrification. Under the更多还原