好氧反硝化菌BN5脱氮降苯特性

以好氧反硝化菌Pseudomonas sp.BN5开展去除硝态氮实验，同时研究其降解苯的特性。结果表明，在最佳转速180 r·min-1条件下，菌株在72 h内可完全降解80 mg·L-1苯；同时，硝态氮的去除率为93.2%。氮平衡分析表明：57.1%的硝态氮转化为胞内氮，32.7%以含氮气体形式被去除；细胞主要通过好氧反硝化和细胞同化作用脱氮。高浓度的苯对细胞生长和硝态氮的去除均有抑制作用，可通过固定化细胞提高降解性能。固定化菌在批式反应器中能高效降苯脱氮，且能够保证反应器的稳定。菌株Pseudomonas sp.BN5可以有效的去除苯和硝酸盐，为该菌的实际应用奠定了基础。

Characteristics of simultaneous removal of nitrate and benzene by an aerobic denitrifying bacterium BN5

The simultaneous removal of nitrate and benzene by an aerobic denitrifying bacterium Pseudomonas sp. BN5 was investigated in this study. The results showed that 80 mg·L-1 benzene could be completely degraded by BN5 within 72 h at the optimal rotation speed of 180 r·min-1, and NO3--N removal rate could reach 93.2% at initial concentration of 10.49 mg·L-1. The nitrogen balance analysis indicated that 57.1% NO3--N transformed to intracellular nitrogen and 32.7% NO3--N was removed as nitrogenous gas. Nitrate removal was mainly realized by aerobic denitrification and cell assimilation. Benzene with high concentration inhibited the cell growth and nitrate removal, and the degradation performance could be improved by cell immobilization. The immobilized bacteria could efficiently degrade benzene and nitrate in a batch reactor, and maintain the stability of this reactor. This study indicated that the strain Pseudomonas sp. BN5 could effectively remove benzene and nitrate, which laid a foundation for its practical application.