贫营养好氧反硝化菌群的水库原位投菌脱氮特性

Nitrogen removal characteristics of mixed aerobic denitrification bacteria under in-situ biological inoculation

摘要:

[目的] 分析水深和温度对好氧反硝化菌群的影响并探索其脱氮特性,以期为微污染水库水生物脱氮提供依据。[方法] 从微污染水源水库表层沉积物中富集、驯化、筛选得到贫营养好氧反硝化混合菌群;应用好氧反硝化混合菌进行硬质瓶子和软质瓶子水库原位投菌实验分析其脱氮性能。[结果] 实验结果表明:硬质瓶子系统(无水压影响)各个水深下的硝氮完全去除,软质瓶子(有水压影响)在0.5、5.0 m达到90.66%和100%,其余水深最大为99.61%、80.55%、67.01%和64.73%;亚硝氮并没有出现积累;氨氮由于实验后期菌体的死亡略有上升;水深0.5、5.0、7.5、10.0、12.5、15.0 m下的总氮在实验结束时,硬质瓶子的去除率达到50.11%、61.49%、56.24%、44.50%、36.80%和38.73%,软质瓶子达到33.47%、60.61%、43.98%、36.28%、27.52%和28.57%; OD₆₀₀与pH都出现先升后降的变化,DO在3-8 mg/L。混合菌在11-30℃表现出很好的脱氮能力,并随着温度上升而增加;水压对脱氮有不利影响。[结论] 该混合菌温度适应性很强,静水压对其脱氮过程有抑制作用。

Abstract:

[Objective] We studied the influences of water pressure and temperature on denitrification, and detected its nitrogen removal characteristics for providing evidence to remediate the micro-polluted reservoir source water. [Methods] Mixed oligotrophic aerobic denitrification bacteria was obtained through enrichment, domestication, and screening processes, which was isolated from sediment in the source water reservoir; and the nitrogen removal characteristics was detected by an in-situ biological inoculation experiment (DO at 3-8 mg/L). [Results] Nitrate of the hard flask system (with water pressure influence) was removed completely, however, at 0.5, 5 m water layer, the nitrate removal rate of the soft flask reached 90.66%, 100%, other layers reached 99.61%, 80.55%, 67.01%, 64.73%. No nitrite accumulated. Because of bacteria death, ammonia had a slight increase. At the end of the experiment, in the 0.5, 5.0, 7.5, 10.0, 12.5 and 15.0 m water layer, the total nitrogen removal rates of hard flask reached 50.11%, 61.49%, 56.24%, 44.50%, 36.80% and 38.73%, however, that of soft system reached 33.47%, 60.61%, 43.98%, 36.28%, 27.52% and 28.57%. OD₆₀₀ and pH first rose and then dropped. The mixed bacteria had prominent nitrogen removal ability between 11℃ and 30℃. [Conclusion] The mixed bacteria have a strong adaptability to temperature and the water pressure has a disadvantage to the nitrogen removal.