低温好氧反硝化菌的选育以及脱氮性能

Breeding and Denitrification Performance of Psychrotolerant-aerobic Denitrifying Bacteria

通过接种某污水处理厂循环活性污泥工艺(cyclic sludge system,CASS)反应池出口活性污泥到培养基,经过对污泥驯化从中分离出1株低温好氧反硝化菌IL-2,温度4℃.对IL-2菌进行常规的生理生化鉴定和16S rDNA测序,鉴定出IL-2菌为Pseudomonas属.考察了不同C/N质量浓度比、温度、溶解氧、接种量、处理时间对菌株IL-2反硝化脱氮效果的研究.随着C/N质量浓度比、处理时间、溶解氧的不断增加,菌株IL-2的脱氮效果逐渐增强;随着温度和接种量的不断增加,菌株IL-2的脱氮效果先逐渐增强后减弱.该菌株在初始硝态氮质量浓度为20 mg/L,C/N质量浓度比为10,温度为4℃,溶解氧为3.5 mg/L,接种量所占体积为30%,处理10 h的条件下硝态氮的去除效果最好,为95.95%.该菌株主要适用于冬季温度较低的市政污水的处理.

In this paper, a psychrotolerant aerobic denitrifying bacterium IL-2 was isolated from the activated sludge from the outlet of the CASS treatment process reaction tank of a sewage treatment plant at a temperature of 4 °C.Routine physiological and biochemical identification and 16 S rDNA sequencing of strain IL-2 identified the strain as Pseudomonas.The effects of different mass concentration ratio of C/N,temperature, dissolved oxygen, inoculum amount and treatment time on denitrification of strain IL-2 were investigated.With the increase of mass concentration ratio of C/N,treatment time, and dissolved oxygen, the denitrification efficiency of IL-2 increased gradually.With the increase of temperature and inoculum amount, the denitrification effect of IL-2 first increased gradually and then decreased.When the initial concentration of nitrate nitrogen was about 20 mg/L,the strain exhibited the best denitrification effect on the wastewater at a mass concentration ratio of C/N of 10,a temperature of 4 ℃,a dissolved oxygen of 3.5 mg/L.The volume of inoculation is 30 %,and a treatment time of 10 hours to achieve 95.95 % degradation rate, indicating its main suitability for treatment of municipal sewage with low temperature in winter.