Engineering Factors Affecting the Formation of Granular Sludge in UASB Reactor
UASB反应器中影响污泥颗粒化的工程因素

The influence of different inoculum sludges involving different microbial populations,different flow models of stream in a bioreactor and different flow rates on the formation of granular sludge were studied.In the granulation process there were four periods:formation of microbial flocs,formation of subcore,growth of subcore and mature of granules.The production of microflocs could be attributed to acid forming bacteria.The dynamic transfer caused by moving phases and the hydraulic shear effect are the most important factors affecting the formation of subcore.A new concept,lowest limitted flow rate was proposed,that is the lowest flow rate to form the expanded sludge bed.A sufficient feed rate (higher than the lowest flow rate),an appropriate sludge charge and an equal distribution of feed as well as a suitable alkality in medium are the main factors for the scale up and process control of UASB