Comparative study of aerobic granular sludge with different carbon sources: Effluent nitrogen forms and microbial community

The effects of the three carbon sources glucose, sodium acetate, and sucrose on the transformation of nitrogen and phosphorous forms in an aerobic granular sludge (AGS) system were investigated. In addition, the microbial community in the sludge was analyzed. Dissolved organic nitrogen removal efficiency in the sodium acetate group remained good throughout the experimental period, with a removal rate of around 90%. The members of Paracoccus and Anaerorhabdus, could hardly use saccharides and therefore accounted for a small amount of the overall bacteria in the groups with glucose and sucrose. The proportion of membrane transport function genes was the largest in the sodium acetate group, with the value reaching to 14.05%. The gene abundance of Glycolysis in three groups were 1.12, 1.06 and 1.09%, respectively. Meanwhile, the genes nirK, norB/C, and nosZ, responsible for the conversion of nitrite to nitrogen in the sodium acetate group were higher than the glucose and sucrose groups. Gene abundance of Glycolysis was largest in the glucose group.

Automated summary

This study found that sodium acetate had the highest efficiency in removing dissolved organic nitrogen in an aerobic granular sludge system. Analysis of microbial communities showed that members of Paracoccus and Anaerorhabdus were less in glucose and sucrose groups. Additionally, the sodium acetate group had the highest abundance of membrane transport function genes.