【作者】 刘静文；

【导师】 顾平；

【作者基本信息】 天津大学 ， 环境工程， 2004， 硕士

【摘要】 水体中氮污染引起的问题，严重的影响着水体生态系统和人类的健康生活。研究高效、经济的脱氮方法已经成为当前环境工作者一项重要的研究课题。 基于传统硝化反硝化的脱氮原理以及膜生物反应器的优点，采用前置缺氧－好氧膜生物反应器作为本次试验的主要工艺，处理高浓度氨氮废水。希望通过运行特性及试验结果来说明此方法的可行性并依据其不足之处，加以改进和完善。 试验主要分为两个阶段：第一阶段采用配水的方法来模拟高氨氮废水。进水平均 COD 为 269mg/L，平均去除率为 85%，进水平均氨氮浓度为 63mg/L，去除率仅为 49%。试验中出现以丝状菌得过量生长导致的活性污泥膨胀现象，SVI平均为 203mL/g，最高达到 401mL/g。丝状菌的大量滋生导致系统内的微生物生长受抑制，影响总氮的去除。此外，氨氮污泥负荷、C/N 比、pH 值以及污泥活性等都对脱氮效果有影响。 第二阶段采用稀释后的生活污水添加硫酸铵的方法来模拟高氨氮废水。由于生活污水中的微生物以及微量元素的补给，活性污泥性状良好，SVI 平均为104mL/g，没有发生丝状菌过量生长的现象。COD 的去除效果较好，平均去除率达到 86％，而且对于进水出现的 COD 冲击负荷，MBR 系统显现了其抗冲击负荷的能力，出水 COD 满足污水回用要求。由于膜的截留作用，使得有机物在反应器内积累，混合液 COD 增高，造成膜堵塞现象异常严重，需要频繁的进行膜清洗以保证系统的稳定运行。进水氨氮平均值为 436mg/L，去除率达到为 89％，但是由于原水中 C/N 值过低、停留时间比较短等原因造成亚硝酸盐严重积累，影响反硝化效果，使得总氮的去除率最高仅为 50%。 从整个试验结果来看，此组合工艺对于有机物和氨氮的确有较高的去除效果，系统具有抗冲击负荷的能力。但是混合液内有机物浓度的增高引起膜污染现象严重，必需采取有效的物理、化学或生物等方法来解决；同时亚硝酸盐过量积累造成脱氮效果不佳的状况也要加以解决。论文结尾提出了短程硝化反硝化工艺的设想以及系统相应的改进方法。更多还原

【Abstract】 Nitrogen pollution has become a big problem to the health and survival of aquaticorganisms and human beings. It is an arduous task for environmental engineers todevelop more and more efficient, economic processes to solve this problem. On the basis of existed nitrogen treatment processes, an anoxic-oxic MBR waschosen to treat the high-strength synthetic ammonia wastewater. It meaned to makefull use of nitrification and denitrification as well as advantages of membranebioreactor (MBR) during the treatment. The experiment was divided into two parts according to sources of rawwastewater. At the first part, the influent was synthetic wastewater. In this part ofexperiment the average COD concentration and removal efficiency were 269mg/L and85%. And the ammonia concentration and removal efficiency were 63mg/L and 49%separately. However, the quality of influent caused sevious filamentous bulging ofactivated sludge and the maximum SVI was as high as 401mL/g, which restrained thegrowth of nitrifying bacteria, and brought bad effects on nitrogen removal. In addition,the sludge loading, C/N ratio, pH value and activity of sludge were main influcingfactors for nitrogen removal. In the second part, the influent was made by diluted domestic sewage added withammonium sulfate. Due to multiple microorganisms and trace elements supplied fromdomestic sewage, the sludge was active and average SVI was only 104mL/g. TheCOD removal was well and MBR showed an ability to resist impact loads, whichpromised the COD effluent to be lower than the reuse water standard. Because ofmembrane seperation, the COD value in mixed liquor was so high that membranefouling happened seriously. In order to insure normal operation, it was necessary tomake membrane cleaning frequently. The average ammonia concentration was436mg/L and its removal efficiency was as high as 89%. However, C/N ratio andshort hydraulic retention time caused nitrite accumulation in the reactor and rejectednitrogen removal, the maximum efficiency of which was only 50%. In order to solve the problem of membrane fouling, it was necessary to apply thephysical, chemical or biological processes to decrease the concentration of organicmatters in mixed liquor. Besides, from the experiment results, it was feasible to keepon the experiment with short nitrification-denitrification process in future. On thecondition of some modification such as adding carbon source, the nitrogen removalefficiency would likely be increased.更多还原