Dimension effect of anammox granule: Potential vs performance

Anammox granule is the key support of anammox sludge bed reactor. In this study, the anammox granules from a steady-state reactor were divided into 6 groups to investigate their dimension effects. The results of batch culti-vation showed that the anammox granules with VMD (volume surface mean diameter) of 2.17 mm had the max-imum SAA (specific anammox activity) of 399.6 +/- 37.6 mg-N/(g-VSS center dot d). The bacterial community analysis demonstrated that Candidatus Kuenenia was the main detectable AnAOB genus in the anammox granules. Q- PCR together with flow cytometry indicated that the total number of viable AnAOB cells ascended with the in-creasing anammox granular size, suggesting the enhancement of nitrogen removal potential. On the contrary, the mass transfer efficiency descended with the increasing granular size, indicating the restriction of nitrogen re-moval performance. The maximum SAA was ascribed to the optimal match between nitrogen removal potential and mass transfer efficiency. The results of this study are helpful to comprehend the nitrogen removal capacity of anammox granules and to promote the optimization of anammox process. (c) 2021 Published by Elsevier B.V.

Automated summary

The study investigated the effects of different sizes of Anammox granules on specific Anammox activity, bacterial community, and nitrogen removal potential. It was found that the nitrogen removal potential increased with the size of the granules, while mass transfer efficiency decreased. The maximum specific Anammox activity depended on the optimal balance between nitrogen removal potential and mass transfer efficiency.