In order to remove total phosphorus (TP) and organic matter in domestic sewage and achieve partial nitrification

an enhanced biological phosphorus removal granular sludge

which was cultivated with synthetic wastewater at room temperature (17-19 ℃)

was used as inoculated sludge in this study. The effect of phosphorus removal and nitrosation on domestic sewage was studied. The experiment showed that the phosphorus removal of the granular sludge could be achieved through 27 d cultivation. The TP concentration of effluent could reach less than 1 mg/L and the TP release in anaerobic stage ΔρTP/ρCOD removal in anaerobic stage (ΔρCOD) could reach 0.3. The change of the aeration methods could make RNA increase from 0 to 90% in a short time. The concentration of NO- 2-N reached 10 mg/L

and the concentration of TP and COD in the effluent were kept below 0.5 and 50 mg/L

respectively. The particle size decreased from 1 200 μm to 1 000 μm and the value of SVI reduced from 32 mL/g to 29 mL/g. The ratio of protein (PN) to polysaccharide (PS) dropped from 2.0 to 1.2. Although the particle size slightly decreased due to domestic sewage

it remained larger than 1 000 μm and the particles possessed better settleability. Thus

the adoption of high and low gradient aeration can achieve phosphorus removal and nitrosation with the removal rate of TP reaching 95%

RNA reaching over 90%

and the particle performance remaining stable.