Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration

摘要: A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers frequent use of sulfate coagulants during drinking water treatment, as well meet demand eutrophication control in warm climate regions. However, major functional bacteria metabolism this emerging biological nutrient removal are still poorly understood. This study was thus designed explore microbes new EBPR by manipulating deterioration, failure restoration a lab-scale system. achieved changing mixed liquor suspended solids (MLSS) concentration monitor evaluate relationships among conversion (including reduction production), P removal, variation microbial community structures, stoichiometric parameters. The results show that stable Denitrifying Sulfur (DS-EBPR) enriched sulfate-reducing (SRB) sulfide-oxidizing (SOB). These synergistically participated process, thereby inducing an appropriate level crucial achieving DS-EBPR performance, i.e. maintaining intensity at 15-40 mg S/L, corresponding optimal sludge 6.5 g/L. range favors competition various energy flows internal polymers (i.e. polysulfide or elemental (poly-S(2-)/S(0)) poly-β-hydroxyalkanoates (PHA)) removal. If exceeded, might deteriorate even fail due enrichment glycogen-accumulating organisms (GAOs). Four methods restoring failed were investigated: concentration, lowering salinity doubling COD loading, non which restored SRB SOB activities DS-EBPR; only final novel approach adding 25 ± 5 mg S/L external sulfide reactor beginning anoxic phase could efficiently restore failure. present represents step towards understanding provides effective remedial measure recovering deteriorating