下流式固定床反应器中反硝化细菌类群及其脱氮效率分析

目的研究下流式固定床反应器的脱氮效果及反硝化细菌群落结构。方法采用多孔陶粒作反硝化细菌固定化载体,研究下流式固定床生物反应器的适宜脱氮条件;扫描电子显微镜观察反硝化菌群的固定化形态并通过16SrDNA测序分析其组成。结果反应最适条件为T=35℃、pH8.0,合成废水处理10hNO3--N去除99%,其中前4h为91%,呈零级反应动力学过程。反硝化细菌主要为杆菌,16SrDNA同源性分析表明反硝化细菌有恶臭假单胞菌、硝基还原假单胞菌、嗜麦芽假单胞菌、睾丸酮丛毛单胞菌、苍白杆菌属等。结论下流式固定床生物反应器的脱氮效果良好,反硝化菌群丰富。

Study on nitrate-nitrogen removal and community analysis of denitrifying bacteria in downflow fixed-bed bioreactor

OBJECTIVE: To study the community of denitrifying bacteria and nitrate-nitrogen removal in downflow fixed-bed bioreactor. METHODS: Porous ceramics were used as immobilization carrier. Optimum conditions for nitrate-nitrogen removal of downflow fixed-bed bioreactor were studied. Morphology of immobilized denitrifying bacteria was observed by scanning electron microscope and their community analysis were processed by 16S rDNA sequencing. RESULTS: The optimum conditions for denitrification were T = 35 degrees C and pH8.0. NO3- -N was consumed 99% within the 10h while removal efficiency reached 91% and followed the zero-order kinetics in the first 4h. Majorities of denitrifying bacteria were bacillus. 16SrDNA homology analysis showed that denitrifying bacteria included P. putida, P. nitroreducens, S. maltophilia, C. testosteroni and Ochrobactrum sp etc. CONCLUSION: There were high nitrate-nitrogen removal efficiency and diversity of denitrifying bacteria in downflow fixed-bed bioreactor.