Enhance nitrogen and phosphorus removal via endogenous denitrification of aerobic granular sludge by directional regulation of electron acceptor
In order to strengthen endogenous denitrification and enhance the efficient utilization of limited carbon sources,in this study,one anaerobic/aerobic/anoxic(A/O/A)sequencing batch reactor and three groups of anaerobic/two-stage short-time aerobic/anoxic(A/(O/A)2)sequencing batch reactors with different aerobic time allocations were implemented to assess sludge granularity and the enrichment of denitrifying glycogen accumulating organisms(DGAOs)across directional regulation of electron acceptor.The findings indicated that the aerobic granular sludge in the two-stage short-time aerobic/anoxic reactor exhibited a more compact structure,superior sedimentation performance,increased availability of electron acceptors in both anoxic and aerobic phases.Furthermore,the capability of DGAOs to accumulate endogenous carbon sources was enhanced.The competition between denitrifying polyphosphate accumulating organisms(DPAOs)and DGAOs for carbon sources reached an equilibrium state within the system.Consequently,the system demonstrated heightened endogenous denitrification and nitrogen removal rates,thereby achieving profound nitrogen and phosphorus removal.Notably,among these reactors,R2,featuring a two-stage short aerobic time allocation of 60minutes in the initial segment and 30minutes in the subsequent segment,exhibited optimal denitrification and phosphorus removal efficacy.This reactor displayed the highest content of DGAOs and superior particle settling performance.During the stable operational phase,R2achieved removal rates of 90.52％,85.71％,and 92.73％for COD,TN,and TP,respectively.Additionally,the endogenous denitrification efficiency reached 58.59％,underscoring its commendable pollutant removal capabilities.
万方数据
维普
