高效亚硝酸型反硝化菌生长特性及脱氮研究

Study of denitrification and growth characteristics of effective denitrifier community reducing nitrite

采用定向筛选法，对反硝化污泥进行驯化和富集，得到了富含亚硝酸型反硝化菌的混合菌体．采用批式试验考察了不同环境因子对该菌体生长和脱氮速率的影响，构建了亚硝酸盐降解动力学模型，初步探讨了菌体在填料床生物膜反应器中的脱氮性能．结果表明，该菌体属于兼性厌氧菌，只有在氧缺乏的环境下才能发生反硝化作用；最适的生长和脱氮条件是以柠檬酸三钠为碳源，ρ（TOC）：ρ（N）=4，温度30℃，pH=9．菌体在此条件下具有很高的活性，比脱氮速率达0．25h^-1，是相关文献报道的6～10倍；具有较强的耐盐特性，可耐受13％的盐浓度；在填料床生物膜反应器中运行稳定，具有较强的抗碳氮源冲击负荷的能力．本研究有利于促进新型短程硝化反硝化工艺的实施以及解决传统反硝化过程中亚氮积累的问题．

The effective denitrifier community reducing nitrite was obtained by the method of directional selection from denitrification sludge. The effects of environmental factors on growth and denitrification rate of the denitrifier community were investigated by batch culture Then, nitrite reduction kinetics model was constructed and the performance of a pack experi ed-bed ments. biofilm reactor seeding with this kind of denitrifier for denitrification was studied. The results show that the denitrifier community is anoxic, which reduces nitrite to nitrogen gas at lower DO concentration. The optimal conditions are： sodium citrate as carbon source, ρ（TOC） ： ρ（N） = 4, temperature 30 ℃, pH 9. Under the optimal condition, the specific denitrification rate of the denitrifier community can reach 0.25 h^-1, which is 6-10 times of that previously reported. The denitrifier community has strong salt-resistant ability, which can tolerate 13% NaCl. Furthermore, it shows the great capability of resisting the variation of carbon and nitrogen loading rate for stable denitrification in the packed-bed biofilm reactor. This study will be beneficial to the implementation of novel partial nitrification/denitrification and solving the problem of nitrite accumulation in the process of traditional denitrification.