n(NO_3^--N)/n(NO_2^--N)对混培养菌与纯培养菌同步脱氮除硫的影响

Effects of the Ratio of (NO_3^--N) to (NO_2^--N) on the Removal of Sulfide and Nitrogen by Mixed Culture and Pure Culture

在温度30℃、pH为7、硫氮比为5/3、厌氧条件下,对比研究了不同n(NO-3-N)/n(NO-2-N)对荧光假单胞菌和铜绿假单胞菌混培养菌同步脱氮除硫影响.随着n(NO-3-N)/n(NO-2-N)减小,荧光假单胞菌、铜绿假单胞菌对NOx-N去除率逐渐增高,而S2-去除率却依次减少,混培养菌对NOx-N去除效率先增加后趋于平稳.n(NO-3-N)/n(NO-2-N)对混培养菌去除S2-几乎没有影响.荧光假单胞菌能迅速将NO-3-N转化为NO-2-N,但NO-2-N转为N2却相对缓慢,培养液中出现NO-2-N累积;而铜绿假单胞菌将NO-2-N还原N2的能力明显比荧光假单胞菌强,培养液未反应的NOx-N以NO-3-N为主,未出现NO-2-N累积.混培养菌对NOx-N转化的情况介于荧光假单胞菌与铜绿假单胞菌之间.荧光假单胞菌同时获得较高NOx-N、S2-去除的n(NO-3-N)/n(NO-2-N)为5/5,铜绿假单胞菌为10/0,混培养菌为5.0/5.0.混培养菌对NOx-N、S2-的同步去除效果优于单菌株荧光假单胞菌和铜绿假单胞菌.

Effects of the ratio of NO3- -N to NO2- -N on removal of sulfide and nitrogen by Pseudomonas fluorescens, Pseudomonas aeruginosa and mixed culture were investigated at the pH value of 7.0, temperature of 30℃ , ratio of sulfide to nitrate of 5/3 and anaerobic condition. Along with the decrease of ratio of NO3- -N to NO2- 2N, NO,- -N, the removal rate by Pseudomonas fluorescens and Pseudomonas aeruginosa increased gradually, while S2＂removal rate redhced. The NO[-N removal rate by mixed culture increased first and became steady along with the decrease of ratio of NO3- -N to NO2- -N. The ratio of NO3- -N to NO2- -N had hardly influence on S2- removal by mixed culture. Accumulation of NO2- -N occurred due to a faster rate of NO3- -N reduction over NO2--N reduction in the liquid culture of Pseudomonas fluorescens. Accumulation of NO2- -N did not occur in the liquid culture of Pseudomonas aeruginosa because it has a stronger ability to convent NO2- -N than Pseudomonas fluorescens. The behavior of NO,- -N by mixed culture in located between Pseudomonas fluorescens and Pseudomonas aeruginosa. The optimum ratio of NO3- -N to NO2- -N to achieve high removals of sulfide and nitrogen for Pseudomonas fluorescens and mixed culture were 5/5, 10/0 for Pseudomonas aeruginosa. The performance of sulfide and nitrogen removal by the mixed culture was higher than that by Pseudomonas fluorescens and Pseudomonas aeruginosa.