Effect of Nutrient on Sludge Settling Property and Bulking Controls
营养物质对污泥沉降性能的影响及污泥膨胀的控制

The effect of nutrient (N and P) deficiency on activated sludge settleability and characteristics of activated sludge flocs in Sequencing Batch Reactor (SBR) fed with brewery wastewater were investigated. The results showed that the activated sludge had good settling properties at influent BOD5/N/P was 100/5/1,100/5/0.8 and 100/4/0.8 respectively. When BOD5/N/P was 100/0.94/0.31,100/2/0.4,100/3/0.6 respectively, the sludge settleability became worse due to excessive growth of filamentous. When BOD5/N/P was 100/0.94/1,100/5/0.31,100/5/0.4,100/5/0.6 respectively, non-filamentous activated sludge bulking occurred. Adding sufficient nutrient to the influent, the sludge bulking was controlled effectively and the low SVI was recovered. When increasing COD loading rate, the duration of recovery could be diminished. When nitrogen and phosphorus were insufficient synchronously, aerobic granular sludge was formed which was averagely 2mm-6mm in diameter.