低C/N摩尔比好氧反硝化菌的筛选及脱氮特性

Screening and denitrification characteristics of low C/N ratio aerobic denitrifying bacteria

从石化废水处理厂活性污泥中分离得到1株低C/N摩尔比的好氧反硝化菌株AD-7,通过形态学观察、生理生化试验及16S rD NA测序,确定其为假单胞菌属(Pseudomonas sp.)。通过单因素实验确定菌株适宜的好氧反硝化培养条件为:丁二酸钠为碳源、培养温度为30～35℃、初始pH 6. 0～7. 0、摇床转速为150～200 r/min。在适宜的好氧反硝化培养条件下,研究了菌株生长情况与反硝化脱氮特性。结果表明,菌株生长与反硝化脱氮基本同步,并且在菌株培养12 h时,硝酸盐氮和总氮的去除率分别高达90. 47%和86. 06%,未出现亚硝酸盐氮的明显积累。因此,菌株AD-7能够通过完全反硝化实现总氮的有效脱除,在低C/N摩尔比废水脱氮方面具有潜在应用价值。

A low C/N molar ratio aerobic denitrification strain AD-7 is isolated from the activated sludge of petrochemical wastewater treatment plant.It is identified as Pseudomonas sp based on the morphological observation,physiological and biochemical test and 16 S rD NA gene sequence analysis.Through single factor experiment investigations,the optimum aerobic denitrification culture conditions are settled as follows:sodium succinate is used as carbon source,culture temperature is set at 30-35℃,initial pH is 6.0-7.0 and rotation speed is 150-200 rpm.Under the optimum aerobic denitrification culture conditions,the growth and denitrification characteristics of the strain are studied.Study results show that the growth of the strain keeps basically synchronous with denitrification,the removal rates of nitrate-based nitrogen and total nitrogen can reach 90.47%and 86.06%respectively after 12 hours of cultivation,and there is no significant accumulation of nitrite-based nitrogen during the whole process.Therefore,the strain AD-7 can remove effectively total nitrogen by complete denitrification and has potential application value in denitrification of low C/N ratio wastewater.