脱氮塔中一株异养硝化真菌的分离鉴定及其脱氮特性

在微生物净化燃煤烟气技术研究中，NO、NOx的脱除效率不高，达不到工艺要求。国内外对于微生物法净化燃煤烟气NO、NOx的细菌作用研究较多，而对真菌的作用却研究很少。为了提高微生物法对燃煤烟气NO、NOx的脱除效率，对脱氮塔生物膜中的异养硝化作用真菌进行了分离、纯化及鉴定，通过摇瓶实验研究了真菌对亚硝酸盐（NO2-）的作用特征，在脱氮塔中对NOx的脱除效率进行了实验验证。实验结果：从脱氮塔生物膜中分离纯化的真菌为木霉属的棘孢木霉Trichodema asperellum（简称：1LNL菌株）；该1LNL菌株能直接将NO2-氧化为NO3-，在实验周期为10 d的条件下，细菌对照组硝化率为31.5%、空白对照组硝化率为8.4%，1LNL菌株的硝化率能达到25.0%，实验证明真菌1LNL菌株具有一定的硝化作用；将1LNL纯菌株扩大培养液400 mL投加到脱氮塔中，NO的脱除率平均提高了4.39%，NOx的脱除率平均提高了4.00%，真菌1LNL能显著提高脱氮柱NO、NOx的脱氮效率。在微生物净化烟气中NO、NOx的研究实践中，真菌的作用应加以重视并应展开更加深入、系统的研究。

Isolation and identification of a heterotrophic nitrifying fungus on denitrification characteristics in denitrifying tower

In the study of microbial technology purifying coal-fired flue gas,the removal efficiency of NO and NOx is not sufficiently high to meet technical requirements. Locally and internationally,much research has been done on the bacterial purification of NO and NOx. However,the function of fungi has been poorly studied. To improve the removal efficiency of NO and NOx,we firstly isolated,purified,and identified fungi from the biofilm of the denitrifying tower. Subsequently,a shake flask experiment was conducted to study its characteristics using nitrite (NO2-),and,finally,we performed further experiments to study its effect on NO and NOx removal efficiency in the denitrifying tower. The strain 1LNL was identified as Trichoderma asperellum,and it could directly oxidize NO2- into NO3-. Ten days later,the nitration rate of the bacteria control group was 31.5%,and the nitrification rate of the blank control group was 8.4%. The nitrification rate of strain 1LNL was 25.0%,showing the nitrification function of strain 1LNL. We placed a pure,expanding culture (400 mL) of strain 1LNL in the denitrifying tower. The removal rate of NO and NOx increased by 4.39% and 4.00% on average,respectively. Since strain 1LNL could improve the denitrification efficiency in the denitrifying tower,the role of fungi should be considered and further researched.