中文摘要：

采用两级UASB-A/O组合工艺处理实际高氨氮城市生活垃圾渗滤液,在获得稳定的有机物与氮同步去除的前提下,重点考察游离氨（FA）与游离亚硝酸（FNA）对短程硝化稳定性的影响。在UASB1中进行反硝化同时产甲烷以去除部分TN和部分COD,在UASB2通过产甲烷进一步去除COD,在A/O反应器中主要实现高氨氮的短程去除和剩余COD的降解。试验共进行104 d,历经短程硝化稳定、破坏和恢复3个阶段。结果表明,当最小FA浓度控制在3.1 mg.L^-1以上时,系统可维持稳定的短程硝化,NH＋4-N去除率、NO-2-N积累率、TN去除率分别可达到99%、95%和86%。当FA浓度小于0.6 mg.L^-1时,在原水碱度充足且过曝气的条件下,仅依靠FA对NOB的抑制作用,难于维持短程硝化,NO2^--N积累率下降到29%。前两阶段的FNA浓度均低于0.011 mg.L^-1,没有对NOB起到抑制作用,而在第3阶段,FA浓度仍维持在较低浓度,但系统FNA浓度通过降低pH值而大幅度提高（最大值为0.414 mg.L^-1）,从而利用FA和FNA的协同抑制作用迅速恢复并维持短程硝化,NO2^--N积累率升高到92%。可见FA与FNA是实现并维持城市生活垃圾渗滤液短程硝化的重要影响因素。

英文摘要：

A lab-scale two-stage UASB-A/O combined process was used to investigate the effect of free ammonia （FA） and free nitrite acid （FNA） on the short-cut nitrification of municipal landfill leachate rich in ammonia nitrogen （NH4^＋-N） on the premise that the COD and nitrogen were removed simultaneously. The denitrifieation and methanogenesis were conducted in UASB1 simultaneously for the partial removal of TN and COD. The effluent COD of UASB1 was further removed in the UASB2 by methanogenesis. Subsequently, the denitrification of NOx^--N in the returned sludge using the residual COD and the short-cut nitrification was achieved in the A/O reactor. The experiment experienced three stages in 104 d. the stable short-cut nitrification, the damaged short-cut nitrification, and the recovered short-cut nitrification. The results showed that when the lowest FA was above 3. 1 mg · L^-1 the stable short-cut nitrification could be achieved and NH4^＋ N removal efficiency, NO2^-N accumulation ratio and TN removal efficiency were 99%, 95% and 86%, respectively. When the FA was lower than 0.6 mg ·L^-1 with sufficient alkalinity and extended aeration, the short-cut nitration was damaged rapidly and NO2^--N accumulation ratio decreased to 29% due to the weak inhibition of low FA on NOB. FNA was lower than 0. 011 mg · L^- 1 at previous two stages, which led to the failure of inhibition on NOB. While FNA was increased considerably in the 3rd stage （the highest FNA was 0. 414 mg · L^- 1） by decreasing pH, the short-cut nitrification was recovered soon and maintained and NO2^--N accumulation ratio increased to 92% owing to the cooperative effect of FA and FNA. In brief, FA and FNA were important factors to achieve and maintain the short-cut nitrification of the municipal landfill leachate.