一个氨氧化菌群的筛选及除氮特性

Screening and ammoxidation characteristics of an ammonium oxidizing bacteria group

摘要:

摘要:【目的】筛选耐受低C/N比、高氨氮环境的高效氨氧化菌群，为开发新型氨氮去除菌剂奠定基础。【方法】采用多点取样、低C/N比、高浓度氨氮废水强行驯化、驯化液连续梯度稀释等步骤，筛选具有高效去除铵氮能力的氨氧化菌群，并考察不同C/N比、摇床转速和铵氮浓度下目的菌群去除铵氮的特性;分离培养目的菌群中的优势菌株，经形态学观察、生理生化特性测定和16S rRNA序列分析对菌株进行鉴定。【结果】筛选到了3个具有较强去除铵氮能力的氨氧化菌群，其中以JQ8活性最好，对初始NH4+ -N 17.86 mmol/L、C/N比为4的合成废水处理6 d后，NH4+-N去除率达到97.01%;在C/N≥4、NH4+-N≤28.57 mmol/L环境下，菌群JQ8对溶液中NH4+-N的6 d去除率均可达95%，净除氮率接近80%。实验室模拟好氧活性污泥处理系统处理线路板工业废水，用菌群JQ8对系统强化处理7 d后NH4+-N和TN去除率分别达到87.8%和67.9%。分析菌群JQ8组成发现，Defluvibacter sp.、Paracoccus sp．和Aquamicrobium sp．细菌为其主要优势菌株。【结论】从垃圾渗滤液中筛选到一个具有较强铵氮去除能力的氨氧化菌群JQ8，可耐受较低C/N比和高氨氮环境，在强化污水处理系统对工业废水氨氮处理中，表现出良好的效果。

Abstract:

Abstract:［Objective］This study aimed to screen high-performance ammonia oxidizing bacteria (AOB) resistant to a high concentration of ammonia-nitrogen and low C/N ratio，for the development of novel AOB agents.［Methods］Multipoint sampling，compulsory domestication，gradient dilution of domestication liquid were conducted to screen AOB with efficient and stable ammonia-nitrogen removing ability，and effects of different factors on its ammoxidation ability including C/N ratio，shaking speed and ammonia-nitrogen concentration were studied． Dominant strains were screened and identified by morphological observation，physiological and biochemical properties test and 16S rRNA sequence analysis．［Results］Three efficient AOB were obtained，among them a micro-flora named JQ8 showed the highest activity． The ammonia-nitrogen removal rate reached 95.07% in a simulated wastewater with 17.86 mmol/L of initial ammonia-nitrogen at C/N 4 treated by JQ8 for 6 days． Moreover，its ammonia nitrogen removal rate kept above 95% and net nitrogen removing rate nearly 80% in the solution with a C/N ratio above 4 and an NH +4 -N concentration below 28. 57 mmol/L．The circuit board industry wastewater was treated using the laboratory-simulated aerobic active sludge disposal system．The removal rate of NH +4 -N and total nitrogen reached 87.8% and 67. 6% respectively after 7 days’treatment using JQ8．Defluvibacter sp． ，Paracoccus sp． and Aquamicrobium sp． were identified as the dominant strains after the composition analysis of JQ8．［Conclusion］An ammonia oxidizing bacteria consortium JQ8 screened from the landfill leachate showed a strong ammonium-nitrogen removal and endurance ability under low C /N ratio and high ammonia-nitrogen concentration，thus is probably applicable to intensify the ammonia-nitrogen removal treatment of industrial wastewater with sewage disposal system．