Performance and population structure of two carbon sources granular enhanced biological phosphorus removal systems at low temperature. (March 2020) - Wang, Shaopo
Graphical abstract: Highlights: Highly efficient PO4 3− -P and COD removal were achieved in SBR-1 and SBR-2. Granules disintegration attributed to filamentous bacteria ( Thiothrix ) at long-term low temperature. The acetate system preferred to utilize intracellular Mg/K-polyP to produce ATP for VFA uptake rather than glycogen. Dechloromonas could use both oxygen and nitrate as electron acceptors for phosphate uptake. Abstract: This study explored the effect of two carbon sources on performance and population structure of granular enhanced biological phosphorus removal systems at long-term low temperature by using two sequencing batch reactors, with acetate (SBR-1) and propionate (SBR-2) as carbon sources respectively. Results showed that highly efficient EBPR were successfully achieved, and the average PO4 3− -P and COD removal efficiency of SBR-1 and SBR-2 were 94.2%, 87.1% and 98.2%, 87.0%, respectively. Moreover, the acetate system preferred to utilize intracellular Mg/K-polyP to produce ATP for VFA uptake rather than glycogen. High-throughput sequencing analysis revealed that the abundance of Rhodocyclaceae were 31.7% (SBR-1) and 71.7% (SBR-2), and genus Dechloromonas was enriched to 60.5% with propionate, evidently higher than acetate (1.2%). Furthermore, in addition to oxygen, Dechloromonas could use nitrate as electron acceptors for phosphate uptake. The study further provides support to simultaneous nitrogen and phosphorus removal at low temperature.