[Simultaneous phosphorus and nitrogen removal of domestic sewage with aerobic granular sludge SBR]

By seeding aerobic granular sludge cultivated from artificial wastewater, an anaerobic/aerobic SBR was applied to treat domestic sewage of high COD, TN and SS. The stability of granular sludge and the removal of organic pollutants, nitrogen and phosphorus of domestic sewage were investigated. After one month incubation, the reactor had good pollutant removal performances and run stably. The ratio of granular sludge to total suspended solids was over 68% all along. The sludge concentration was 5 000 - 6 000 mg/L and SVI value was 20 - 35 mL/g. After three months operation, most of the granules were over 1.25 mm instead of 0.6 - 0.9 mm in the beginning. During the stable operation phase of the granular sludge SBR, the average removal efficiencies of COD, TOC, phosphate, ammonium nitrogen, total nitrogen, SS were 83.04%, 70.41%, 94.30%, 86.51%, 41.82% and 85.89%, respectively. Analysis of the pollutant removal in typical cycle showed that the granular sludge had good simultaneous phosphorus and nitrogen removal performance.