Cultivation Of Denitrifying Phosphorus Removal-aerobic Granular Sludge And Treatment To Municipal Wastewater

Enrichment of denitrifying polyphosphate-accumulating organisms (DNPAOs) and competition between polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) under different carbon sources were investigated using denitrifying phosphorus removal-aerobic granular sludge (DPAGS). DNPAOs have enriched successfully in two lab-scale sequencing batch reactors (SBRs) under anaerobic-aerobic-anoxic cycles and fed with synthetic water containing acetate (R1) or propionate (R2) as the sole carbon source. The granules in R1 were larger and smoother with more regular surface, which helped R1 shorten the start-up time obviously. The granules in R2 had a higher biomass activity and better enrichment of DNPAOs. Also more stable nutrient removal performance was achieved in R2. It suggested that acetate was in favor of granulation process, while propionate might provide PAOs with a selective advantage over GAOs. To obtain a more detailed insight to the PAOs and GAOs competition, PHB and glycogen content in granules were measured in a typical cyclic study during the steady operation.A sequencing batch reactor (SBR) was conducted to study the performance of physical activities and wastewater treatment ability during reactivation period after 1-month storage. Results showed that the colour of granular sludge became dark, which turned to be brownish-yellow after 11d when the reactor was restarted.were still able to retain good ability after short-time storage. COD, NH4+ -N, PO43- -P was fully reactivated after 14d,40d,40d, respectively. The condition of DNPAOs was well after 50d. Wastewater treatment experiment indicated microorganism can not grow well when C/N＜5.1, additional carbon sources were used in this experiment and proportion of real wastewater was kept at 60%.