一体化A/O生物膜反应器脱氮特性的研究

【作者】 姜苏；

【导师】 周集体；

【作者基本信息】 大连理工大学 ， 环境工程， 2004， 硕士

【摘要】 传统的生物脱氮工艺或是在分隔的具有不同DO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。这样的工艺存在能耗高，设备利用率低，脱氮效果差，投资高等问题。针对这些问题，本论文提出了一种新型的一体化生物膜脱氮反应器。使曝气不仅为处理过程提供必需的溶解氧，而且实现脱氮过程中必要的混合液回流，从而减少了系统的动力消耗；同时实现了脱碳、脱氮过程在一个单体设备中完成，设备紧凑，占地面积小，且减少了回流设备，从而降低了设备投资费用。 用PIV二维流场测试技术对反应器内部流场进行了测定，并根据测定结果对反应器进行了改进；用生活污水考察了改进后反应器的脱碳、脱氮性能；用模拟污水考察了曝气量、进水COD／TN比值等运行参数对反应器处理效果的影响并探讨了反应器的脱氮机理。实验结果表明： （1）在一体化反应器内可同时实现好氧和缺氧两种环境，并且利用曝气产生的空气动力实现了脱氮过程必需的液体回流。减少了动力消耗也降低了设备投资费用。 （2）用反应器处理实际生活污水，当水温为20～24℃，水力停留时间HRT=24h时，反应器对COD的平均去除率为90％，硝化率和TN的去除率分别达到85％和70％，出水NO₃-N和NO₂-N的平均浓度分别为15mg／L和1mg／L。且反应器对模拟污水具有更好的处理效果。 （3）在一体化反应器内，碳源对于硝化过程和反硝化过程来说是矛盾的，实验结果表明，进水COD／TN比值为5时，反应器的硝化能力和反硝化能力匹配得最好。 （4）一体化反应器的脱氮过程，一方面是基于不同分区内发生的硝化反应和反硝化反应，相互间通过液体循环而实现的；另一方面是基于反应器的每个分区内都同时发生硝化反应和反硝化反应而实现的。更多还原

【Abstract】 Traditional biological nitrogen removal processes either need several separated tanks with different DO concentrations, or need sequential aerobic and anoxic environment in turn in a single reactor. Thus these processes have many shortcomings, such as high cost of facility construction, large consumption of energy, low nitrogen removal efficiency and high cost of operation. As to these shortcomings, an integrative biofilm reactor is designed, which can realize carbon and nitrogen removal simultaneously in a single tank and can also realize circulation necessary for nitrogen removal only by aeration.First, flow field in the integrative reactor are tested with PIV and then the reactor is modified according to the testing results. Second, research is carried out on carbon and nitrogen removal in domestic wastewater with the modified reactor. Finally, mechanism of the reactor and also effects of operating conditions, such as influent COD/TN and aeration rate on the reactor’s removal efficiencies are investigated with synthetic wastewater. The following conclusions can be obtained.(1) Oxic and anoxic environment can be created simultaneously in the integrative reactor, and nitrifying liquid can be circulated without pump in the reactor, thus the electric consumption and the cost of facility construction could be reduced.(2) The research results of domestic wastewater show that when HRT is 24h and temperature is between 20 to 24 degrees centigrade, the COD removal efficiency is about 90%, nitrification rate and TN removal efficiency reach 85% and 70%. The effluent concentration of NOa-N and NO2-N are about 15mg/L and Img/L respectively. When it comes to synthetic wastewater, the reactor has better removal efficiencies.(3) Carbon is benefit for denitrification, but is disadvantageous to nitrification. The experiment results indicate that when the ratio of influent COD/TN is 5, the reactor’s nitrification ability and denitrification ability could match each other best.(4) The integrative reactor’s nitrogen removal process is based on the following two aspects. One is that nitrification is mainly displayed in the oxic section and denitrification is dominantly carried out in the anoxic section and they harmonize with each other by circulation. And the other is that nitrification and dinitrification could be displayed simultaneously in each seation.更多还原