Abstract: Cerium nitrate affects SOUR (specific oxygen uptake rate), biomass growth velocity and biologic phase of activated sludge in various degrees. Results show that cerium nitrate (50mg／L) can greatly improve the quality of sludge. Then, the conventional activated sludge was inoculated with aerobic SBR where glucose and sodium acetate were used as the carbon sources to study the formation of aerobic granular sludge. The composition of extracellular polymeric substances(EPS) and the hydrophobicity of sludge, as well as MLSS, SVI, COD, TN and TP were observed. The results indicate that cerium nitrate could promote the formation of aerobic granular sludge. The removal rates of COD, TP and TN are 95％, 80％ and 85％, respectively.

Key words: extra-cellular polymeric substances(EPS) , granulation of active sludge, cerium nitrate