Si Wen-Gong, Lü Zhi-Gang, Xu Chao
Jiangsu Jiangda Ecological Science and Technology Co., Ltd., Wuxi 214061, China.
Huan Jing Ke Xue. 2011 Nov;32(11):3448-54.
The removal capabilities and tolerance of high concentration of ammonia-nitrogen of heterotrophic nitrifiers were studied. Methods included multi-point sampling, domestication, gradient dilution of domestication liquid, color indicator as rapid nitrification detection and isolation from streaking plate were conducted to screen heterotrophic nitrifiers. The strains were identified according to the sequence analysis of 16S rDNA. After inoculating the strains into ammonia-nitrogen wastewater, changes of nitrogen compounds were measured in order to understand their denitrification characteristics. The denitrification efficiency was optimized by improving the C/N ratio, changing the compatibility of the strains and mixing the compatible strains with the domesticated bacterial suspension. Finally 8 high-efficiency heterotrohic nitrifiers were obtained, and named as N1-N8 respectively. Phylogenetic analysis showed that 8 strains belonged to Comamonas genus, Rhodococcus genus, Pseudomonos genus, Arthrobacter genus and Paracoccus genus, respectively. When the initial concentration of ammonia nitrogen was 256.9 mg x L(-1) and the C/N was 5.5 of the artificial wastewater, the removal rates of ammonia nitrogen by the strains were about 65%-80%, and the stain N4 was the best. When the C/N ratio of the wastewater increased to 8.0, the ammonia nitrogen removal rates of the strains correspondingly increased to about 80% -90%. As the strains compatibility, the denitrification rate of N4 + N5 + N6 was 88.2% in the artificial wastewater with initial ammonia nitrogen concentration was 261.1 mg x L(-1) and initial C/N ratio was 5.5, which was higher than that of any single strain. The ammonia nitrogen removal rate could reach to 99.8% when N4 + N5 + N6 were combined with the domesticated bacterial suspension. In the artificial wastewater, when the initial ammonia nitrogen increased to 446.9 mg x L(-1) and the C/N ratio decreased to 3.2, the ammonia nitrogen removal rate of the mixed strains which composed of N4 + N5 + N6 and domesticated bacterial suspension was 99.9%. There was almost no nitrite and nitrate nitrogen accumulated in eventually, and the total nitrogen removal rate was 66.5%. The nitrogen which was assimilated by the strains was only 33% of the lost ammonia nitrogen. It shows that the strains which could not be isolated in the domesticated bacterial suspension had significant synergies effects on ammonia nitrogen removal of the isolating strains.
研究了异养硝化菌对高浓度氨氮的去除能力及耐受性。方法包括多点采样、驯化、驯化液梯度稀释、以颜色指示剂作为快速硝化检测以及从划线平板上分离，以筛选异养硝化菌。根据16S rDNA序列分析对菌株进行鉴定。将菌株接种到氨氮废水中，测定氮化合物的变化以了解其反硝化特性。通过提高碳氮比、改变菌株的配伍性以及将配伍菌株与驯化菌悬液混合来优化反硝化效率。最终获得了8株高效异养硝化菌，分别命名为N1 - N8。系统发育分析表明，8株菌分别属于丛毛单胞菌属、红球菌属、假单胞菌属、节杆菌属和副球菌属。当人工废水中氨氮初始浓度为256.9 mg·L⁻¹且碳氮比为5.5时，各菌株对氨氮的去除率约为65% - 80%，其中菌株N4效果最佳。当废水碳氮比增至8.0时，各菌株的氨氮去除率相应增至约80% - 90%。就菌株配伍而言，在初始氨氮浓度为261.1 mg·L⁻¹且初始碳氮比为5.5的人工废水中，N4 + N5 + N6的反硝化率为88.2%，高于任何单一菌株。当N4 + N5 + N6与驯化菌悬液组合时，氨氮去除率可达99.8%。在人工废水中，当初始氨氮增至446.9 mg·L⁻¹且碳氮比降至3.2时，由N4 + N5 + N6和驯化菌悬液组成的混合菌株的氨氮去除率为99.9%。最终几乎没有亚硝酸盐和硝酸盐氮积累，总氮去除率为66.5%。菌株同化的氮仅占损失氨氮的33%。这表明在驯化菌悬液中未能分离出的菌株对分离出的菌株去除氨氮具有显著的协同作用。
