An updated enhanced biological phosphorus removal-sludge shifting SBR process was used for the treatment of synthetic wastewater. The role of extracellular polymeric substances (EPS) in the enhanced phosphorus removal process was investigated. As the sludge reflux ratios (characterized by sludge shifting volumes) was set as 0

15% and 30%

the content of EPS in the sludge was (108.14±9.68) mg·(g MLSS)-1

(128.17±1.45) mg·(g MLSS)-1 and (123.35±22.98) mg·(g MLSS)-1

respectively. The total phosphorus removal efficiency in sludge (by sludge adsorption) was 82.14%±0.85%

96.35%±1.25% and 98.99%±0.98%

respectively. Accordingly

the TP concentrations in the EPS at the end of the process accounted for 27.9%±2.55%

57.23%±2.33% and 63.88%±2.87% of the TP concentrations in the sludge

respectively. In addition

the adsorption of phosphorus by EPS was (2.04±0.32) mg·(g MLSS)-1

(5.90±0.38) mg·(g MLSS)-1 and (6.00±0.52) mg·(g MLSS)-1

respectively

during the aerobic phosphorus adsorption process. In all the above cases

the EPS has contributed more than 90% of the phosphorus adsorption capacity of the sludge. The results indicated that in sludge shifting SBR process

the increase of the amount of sludge shifting improved phosphorus content in the EPS and corresponding phosphorus removal

showing that EPS played a major role in the phosphorus removal process. But sludge shifting had almost no impact on EPS content in the sludge.