不同C／N下人工湿地的脱氮效果及其强化措施

以人工湿地为研究对象，分析了不同C／N下人工湿地的脱氮效果。结果表明，C／N为10时，TN、NO2-N和COD平均去除率分别为（75．36±10．55）％、（86．34±9．23）％和（67．60±4．10）％，都显著高于其他2组系统（P=0．006、0．001、0〈0．01）；随着C／N的增加，NO3-N去除率呈现出上升的趋势；NH4-N刚好相反，C／N为1时，明显要高于其他2种情况（P=0〈0．05），平均去除率为（65．42-1-14．31）％。针对C／N为1时人工湿地脱氮效率较低（51．294-14．48）％的情况，对系统进水采取了添加一定量好氧反硝化细菌固定化小球并曝气12h的强化实验措施。结果发现，强化实验条件下TN、NOr-N和N03-N去除率均提高了10％以上，且都要明显高于非强化实验条件（P：0．003、0、0〈0．01），同时NH4-N和COD去除率没有明显差异，研究结果表明，从微生物角度对系统进水进行前处理有助于提高人工湿地脱氮效率。

Nitrogen removal and its amplifying test in constructed wetland under different C/N

The aim of this study was to investigate the removal of nitrogen and the impact of different C/N in constructed wetland. Results indicated that the average removal competence of TN, NO2- -N, COD were （75.36 ± 10.55 ） %, （ 86.34 ± 9.23 ） % and （67.60 ± 4. l0 ） %, respectively, which were significantly higher than that of other two systems （p =0. 006,0. 001,0 〈0.01） when C/N was 10; with the increasing of C/N, the re- moval capability of NO3 -N presented a rising trends ; while at C/N = 1, the average removal amount of NH4 -N was （65.42 ± 14.31 ）% , showing the largest in those three different C/N （p = 0 〈 0.05）. Targeting at the de- fect of lower nitrogen removal quantity at C/N = 1, an amplifying test was adopted which was adding some aero- bic denitrification bacteria immobilized beads into influent and aerating for 12 h. And the experimental results showed that the removal capacity of TN, NO2- -N, NO3 -N increased by more than 10% and considerably higher than non-amplifying test （p =0. 003,0,0 〈0.01 ） , but there were no apparent differences on NH4＋ -N and COD. From the aspect of microorganisms, the pre-treatment of influent contributed to the improvement of nitrogen re- moval ability in constructed wetlands.