打开文本图片集
摘 要：為了提高城市尾水中氮的去除率，优化筛选出一株好氧同步硝化-反硝化细菌，通过调整尾水的氨氮浓度，研究其在不同氨氮浓度的尾水中的反硝化能力。结果表明：好氧同步硝化-反硝化细菌FX7h的硝化和反硝化能力较强，在24，48 h硝态氮降解率分别达到83.1%和91.1%;在氨氮质量浓度为10 mg/L的城市尾水中，总氮、氨氮、硝态氮去除效果最明显，去除率分别为56.9%，70.2%，91.1%;亚硝态氮出现累积，累积率为20%;氨氮质量浓度为15，25 mg/L条件下，总氮与氨氮去除效果明显降低;在25 mg/L条件下，亚硝态去除率增加，硝态氮去除率不明显。因此，好氧同步硝化-反硝化细菌FX7h在氨氮质量浓度为10 mg/L的城市尾水中进行异养硝化和好氧反硝化作用的效果最好，其在实验过程中以去除氨态氮为主。所采用的细菌脱氮方法与传统的生物脱氮相比具有节约运行成本、耐氧性好、平衡p值等优势，有着广阔的应用前景。
关键词：水污染防治工程;同步硝化;好氧反硝化;城市尾水;氨氮浓度
中图分类号：X523 文献标志码：A
Abstract：In order to remove nitrogen from urban tail water， a aerobic simultaneous nitrification-denitrification denitrifying bacteria is optimized and the denitrification ability of the bacteria in tail water with different ammonia nitrogen concentration is studied through adjusting the concentration of ammonia nitrogen in tail water， The results show that the simultaneous Nitrification-aerobic denitrification bacteria FX7h has strong nitrification and denitrification ability， and the degradation rate of nitrate nitrogen reaches 83% and 91% at 24 h and 48 h; the removal efficiency of total nitrogen， ammonia nitrogen and nitrate nitrogen is most obvious in 10 mg/L urban tail water， and the removal rates are 56.9%， 70.2%， and 91.1%， respectively; The nitrite nitrogen has a cumulative rate of 20%; under the mass conditions of 15 mg/L and 25 mg/L of ammonia nitrogen concentration， the removal efficiency of total nitrogen and ammonia nitrogen decreases significantly; under the condition of 25 mg/L， the removal rate of nitrous acid increases and the removal rate of nitrate nitrogen is not obvious. So the aerobic simultaneous nitrification denitrification bacteria FX7h has the best effect on heterotrophic nitrification and aerobic denitrification in urban tailwater with a concentration of 10 mg/L， and the ammoniacal nitrogen is mainly removed during the experiment. Compared with traditional biological nitrogen removal， the bacteria denitrification has the advantages of saving operating cost， oxygen resistance， balanced p value， etc.， and has broad application prospects.
Keywords：water pollution prevention project; simultaneous nitrification; aerobic denitrification; urban tailwater; ammonia nitrogen concentration
传统的生物脱氮过程分为硝化（N+4→NO-2→NO-3）和厌氧反硝化（NO-3→NO-2→NO→N2O→N2）两个过程，需要分别在好氧和厌氧条件下完成[1-2]。20世纪80年代，ROBERTSON等[3]报道了好氧反硝化细菌和好氧反硝化酶系的存在，为生物脱氮技术提供了一种崭新的思路。目前已经发现的好氧反硝化细菌约50多个属，130多个种，包括了无色杆菌属（Achrombacter）、短杆菌属（Brevibacterium）、苍白杆菌属（Ochrobacturum）等[4]。其中环境中最普遍存在的好氧反硝化细菌为假单胞菌属（Pseudomonaceae）、产碱杆菌属（Alcaligenes）、副球菌属（Paracoccus）等[5]。与厌氧反硝化细菌的反硝化相比，好氧反硝化细菌（多为异养硝化菌）的硝化过程和反硝化过程可同时进行，硝化的产物可直接作为反硝化的底物，除去了NO-3和NO-2的积累对反硝化的抑制作用，提高了生物脱氮的速度，且这个过程酸碱相对平衡，能使p值保持在一定范围之内[6-7]。
