无机碳在厌氧氨氧化系统中的迁移转化

Migration and transformation of inorganic carbon in the Anammox system

基于厌氧氨氧化(Anammox)反应,采用13C同位素示踪法分析无机碳(IC)在工艺中的迁移转化路径,考查厌氧氨氧化工艺的固碳潜力及厌氧氨氧化菌相关的固碳机理;同时,结合微生物分子学等方法,通过比较反应前后NH4+-N、NO2--N、TN及IC的变化,分析推导出工艺的固碳机理。结果表明,在进水IC为10.70 mg左右时,系统平均固碳率在12.05%以上;经13C标记处理后的Anammox污泥中13C丰度值由1.07%增加至1.17%以上;Anammox污泥中cbbLR1基因拷贝数经氮素和IC影响后分别为5.79×108copies·g-1和5.56×108copies·g-1,较处理前均有所增加,但变化不明显。进水中投加的IC参与了微生物体内的碳代谢;厌氧氨氧化菌存在遵循卡尔文循环固碳途径的功能基因。cbbLR1基因丰度与氮素浓度之间呈显著相关,与IC浓度之间的相关性不明显,说明该基因丰度对氮素的响应度比IC大。

In this study,the migration and transformation path of inorganic carbon(IC)in Anammox process was identified using the 13C isotope tracer method,and the carbon sequestration potential of Anammox process and the carbon sequestration mechanism of Anammox bacteria were discussed.At the same time,in combination with the microbial molecular methods,the carbon sequestration mechanism of the process was disclosed through comparison of the changes of NH4+-N,NO2--N,TN and IC before and after the reaction.The experimental results showed that the average carbon sequestration rate of the system was above 12.05%when the influent IC was about 10.70 mg.The 13C abundance value of the anaerobic ammonium oxide sludge after 13C labeling treatment increased from 1.07%to over 1.17%.Under the influence of nitrogen and IC,the copy numbers of cbbLR1 gene in Anammox sludge were 5.79×108 copies·g-1 and 5.56×108 copies·g-1 dry sludge,respectively,both of them increased than before treatment,while this change was insignificant.IC added to the influent water participates in the carbon metabolism in the microorganism.Anammox bacteria have some functional genes that follow the Calvin cycle carbon sequestration pathway.The abundance of cbbLR1 gene showed a significant correlation with nitrogen concentration,while an insignificant correlation with IC concentration,indicating that the gene abundance was more responsive to nitrogen than to IC.