Control of Filamentous Sludge Bulking in Aerobic Granular Sludge SBR Process

The aerobic granular sludge was inoculated in SBR and used to treat simulated wastewater after acclimation,with an excellent effect.The variation in sludge morphology during incubation and the removal of pollutants with filamentous sludge bulking were investigated.The role of filamentous microorganisms in the sludge granulation process and control methods of general filamentous bulking were discussed.The filamentous sludge bulking affected the removal rate of COD,but the influence on the removal rates of ammonia nitrogen and TP was little.The filamentous sludge bulking could be controlled to a certain extent by increasing the hydraulic shear in the reactor.Moreover,the problem of sludge bulking could be fundamentally resolved by reducing the ratio of C/N and balancing nutrition in the influent.MLSS of the mature aerobic granular sludge was about 3 000 mg/L with better settleability,and SVI was about 77 mL/g.The removal rates of COD,ammonia nitrogen and TP could reach 94.52%,95% and 90% respectively,showing higher removal rates.