异养硝化-好氧反硝化菌YL的脱氮特性

Characteristics of Nitrogen Removal by a Heterotrophic Nitrification-Aerobic Denitrification Bacterium YL

针对传统自养硝化-厌氧反硝化工艺流程长、脱氮效率低的问题,从驯化成熟且具有高效同步硝化反硝化作用的SBR反应器中筛得1株异养硝化菌YL,经鉴定为铜绿假单胞菌(Pseudomonas aeruginosa),并通过单因子试验和正交试验对其异养硝化和好氧反硝化特性进行了研究.结果表明,菌株YL进行氨氧化作用的最适条件为:碳源为琥珀酸钠、C/N为10、p H为7.0、温度为30℃、转速为160~200 r·min-1,此时氨氧化速率为5.05 mg·(g·h)-1,TOC转化速率为45.95 mg·(g·h)-1,氨氮和TOC去除率分别为100%和90.8%;菌株YL还能够利用亚硝酸盐、硝酸盐和羟胺进行生长代谢,去除率分别为92.7%、93.6%和94.8%;影响菌株YL好氧反硝化性能最主要的因素为C/N,在最优条件(C/N=10,T=30℃,r=200 r·min-1,p H=7)下,硝氮去除率为94.6%,总氮去除率76.3%.表明菌株YL能够独立快速高效地完成异养硝化和好氧反硝化脱氮过程.

Traditional process of autotrophic nitrification-anaerobic denitrification usually has problems of long procedure and low efficiency. To overcome these problems, a heterotrophic nitrification-aerobic denitrification bacterium YL was isolated from a domesticated mature SBR reactor with efficient simultaneous nitrification and denitrification ability, and was identified as Pseudomonas aeruginosa YL. Meanwhile, the characteristics of the nitrogen removal of strain YL was investigated through single - factor experiments and an orthogonal experiment. The results showed that the preferred conditions were: succinate as the carbon source, C/ N ratio of 10, pH of 7. 0, temperature of 30℃ , and the shaking speed of 160-200 r?min - 1 , while the removal rate of ammonia oxidation was 5. 05 mg?(g?h) - 1 , the transformation rate of TOC was 45. 95 mg?(g?h) - 1 , and the removal rates of nitrogen and TOC were 100% and 90. 8% , respectively. Nitrite, nitrate and hydroxylamine could also be metabolized by strain YL, and the removal rates were 92. 7% , 93. 6% and 94. 8% , respectively. The most important influencing factor on aerobic denitrification of strain YL was C/ N ratio. Under the optimal conditions (C/ N = 10, t = 30℃ , r = 200 r?min - 1 , pH = 7), the removal rates of nitrate and total nitrogen were 94. 6%and 76. 3% , respectively. Hence, strain YL could remove nitrogen by heterotrophic nitrification-aerobic denitrification independently, quickly, and effectively.