MFC-好氧颗粒污泥系统中C/N对阴极微生物的影响

Effect of C/N ratio on cathodic microorganisms in MFC-aerobic granular sludge system

摘要:

为了探索微生物燃料电池更广泛的适用性，本试验将好氧颗粒污泥（AGS）与微生物燃料电池（MFC）进行耦合，并采用序批式运行方式，固定进水COD为780 mg/L，通过改变NH4+的浓度（39、50、78和156 mg/L）将碳氮比（C/N）分别调节为5、10、15、20，研究了不同C/N对系统阴极室内微生物的多样性和群落结构产生的影响。通过高通量测序分析显示，随着进水C/N的变化，阴极室内不同菌群的相对丰度都产生了明显的变化。在门水平下，最为丰富的变形菌门（Proteobacteria）的相对丰度在C/N=10时，占比为45%；而在C/N=20时，降为41.1%。在纲水平下，相对丰度变化幅度最大的异常球菌纲（Deinococci）在C/N=5时占比最大达到27.2%，在C/N=20时占比最小只有15.1%。在C/N=15和20的条件下，阴极室内微生物的新陈代谢相对丰度最高，为77.1%，对应的阴极好氧颗粒污泥代谢较强，这对微生物降解COD有着举足轻重的作用。

Abstract:

In order to explore the wider applicability of microbial fuel cells, aerobic granular sludge (AGS) was coupled with microbial fuel cells (MFC) in this experiment, and the sequencing batch operation was adopted, the influent COD was fixed at 780 mg/L, and the C/N ratio was adjusted to 5, 10, 15, 20 by changing the concentration of NH4+ (39, 50, 78 and 156 mg/L), respectively. The influence of different C/N on microbial diversity and community structure in the cathode chamber of the system was studied. High-throughput sequencing analysis showed that the relative abundance of different bacterial communities in the cathode chamber changed significantly with the change of influent C/N. At the phylum level, the relative abundance of Proteobacteria was 45% when C/N=10. When C/N=20, it decreases to 41.1%. At class level, Deinococci with the largest variation in relative abundance can account for 27.2% at C/N=5, and only 15.1% at C/N=20. Under the conditions of C/N=15 and 20, the metabolic relative abundance of microorganisms in the cathode chamber was the highest (77.1%), and the corresponding metabolic strength of the cathode aerobic granular sludge was strong, which played an important role in the microbial degradation of COD.