弥河沉积物的反硝化和厌氧氨氧化过程

本研究选取弥河4个站点为研究对象，在不同季节分别采集沉积物样品，测定理化指标，并采用同位素配对技术和分子生物学方法，研究了沉积物中的反硝化和厌氧氨氧化作用及其影响因素.结果表明，弥河沉积物中的反硝化速率变化范围为151.75~2847.86μmol/（m²×h），厌氧氨氧化速率的变化范围为149.57~2109.17μmol/（m²×h），厌氧氨氧化在氮去除中的贡献量平均达到56.1%.沉积物中的反硝化细菌以nirK型为主，丰度为0.19×10⁶~5.12×10⁶个/g，主要是α-和β-变形菌门；厌氧氨氧化细菌以hzsA为标记基因的丰度范围是2.58×10²~1.14×10⁴个/g，主要为浮霉菌门的Brocadia属细菌.反硝化速率与沉积物中的TN含量和间隙水PO₄^3-呈正相关关系，厌氧氨氧化作用与沉积物中的TN含量呈正相关，而与沉积物密度呈负相关关系，沉积物的理化指标是决定氮去除速率的主要环境条件.弥河的反硝化和厌氧氨氧化作用明显，对减轻氮超标具有重要意义，合理改变沉积环境是有效提高氮去除速率的可参考方式.

Denitrification and anammox processes in sediment of Mihe River,China

Four sites were selected along Mihe River to sample the sediments and characterize physiochemical property to reveal denitrification/anammox processes and their constraints by isotope tracing experiment and molecular biological analysis. The results showed that the rates of denitrification varied from 151.75 to 2847.86μmol/(m²·h), and the anammox rates were in the range of 149.57 to 2109.17μmol/(m²·h). The relative contribution of anammox in the nitrogen removal was in an average of 56.1%. The nirK type was the dominant denitrifier with the abundance of 0.19×10⁶~5.12×10⁶ copies/g in the sediment, which was in the phylum of α- and β- Proteobacteria. The anammox bacteria marked by hzsA gene was in the range of 2.58×10²~1.14×10⁴ copies/g, which belonged to the Ca. Brocadia clades in Planctomycetes. Furthermore, the denitrification rate was positively related with TN content and PO₄^3- concentration, while the anammox rate was positively related with TN content and negatively related with sediment density. The physiochemical property of sediment was the main condition determining the nitrogen removal rates. The results highlight that denitrification and anammox were of great significance to reduce nitrogen eutrophication, and sediment environment treatment was a considerable way to regular nitrogen removal rate.