生物过滤脱除烟气中NOx的中温好氧反硝化分子机制

In coal-fired boiler, the temperatures of flue gases after wet desulphurization are always around 50 oC (i.e., mesothermal environment). However, few methods for the effective removal of NOx have been found at this temperature range. Recently, during the study on NOx removal from flue gas by biofiltration, a novel aerobic denitrifier was successfully isolated at 50℃ and named as Chelatococcus daeguensis strain TAD1, which makes the biofiltration to be a new technic for the removal of NOx at this temperature range. Firstly, using the real-time fluerescent quantitative PCR as a main technic to develop the molecular biology study, and the gene expression regularity of nitrate reductase, nitrite reductase, nitric oxide and nitrous oxide reductase will be explored. The characteristic and physiology information of biofilm containing TAD1 will be analyzed by means of microelectrode, fluorescence in situ hybridization and flow cytometer. The status and evolution rule of TAD1 plus other functional microbe in biofilm will also be discussed, and the transportation pathway of NO enter into the biofiltration system will be analyzed deeply to reveal the molecular mechanism of aerobic denitrification. This study demonstrates the scientific feasibility of mesothermal aerobic denitrification and provides the mechanism for the removal of NOx from the flue gas at mesophilic temperature.

燃煤锅炉湿法脱硫后烟温常在50℃左右（中温），但在该温度范围内缺少有效的脱硝手段。近年来通过对烟气中氮氧化物（NOx）的生物过滤脱除研究，发现了在中温烟气环境下具有高效好氧反硝化特性的新菌种（螯台球菌Chelatococcus daeguensis TAD1），使得生物过滤方法脱除中温烟气中的NOx成为一种新手段。开展以实时荧光定量PCR为主要技术手段的分子生物学研究，探索TAD1四种反硝化酶（硝酸盐还原酶、亚硝酸盐还原酶、一氧化氮还原酶和氧化亚氮还原酶）编码基因的表达规律；结合微电极、荧光原位杂交以及流式细胞等技术，对生长有TAD1的生物膜特性及其原位生理信息进行研究，探讨TAD1等微生物在生物膜中的地位及演变规律，同时深入分析一氧化氮在生物过滤系统中的代谢途径，从而揭示该过程的好氧反硝化分子机制。本研究可证明中温好氧反硝化在科学上具有可行性，为脱除中温烟气环境中NOx提供理论基础。

针对燃煤锅炉湿法脱硫后烟气在常温缺少有效脱硝手段的特点。近年来通过对烟气中氮氧化物（NOx）的生物过滤脱除研究，发现了在中温烟气环境下具有高效好氧反硝化特性的一些新菌种，使得生物过滤方法脱除中温烟气中的NOx成为一种高效脱硝手段。开展了以实时荧光定量PCR为主要技术手段的分子生物学研究，探索了好氧反硝化菌种的四种反硝化酶（硝酸盐还原酶、亚硝酸盐还原酶、一氧化氮还原酶和氧化亚氮还原酶）编码基因的表达规律；结合微电极、荧光原位杂交以及流式细胞等技术，对生长有好氧反硝化菌的生物膜特性及其原位生理信息进行研究，探讨了好氧反硝化菌等微生物在生物膜中的地位及演变规律，同时深入分析了一氧化氮在生物过滤系统中的代谢途径，从而揭示该过程的好氧反硝化分子机制。本研究证明了中温好氧反硝化在科学上具有可行性，为脱除中温烟气环境中NOx提供了理论基础。