The Cultivation Of Aerobic Granular Sludge By Seeding Anaerobic Granules In SBR And The Operation Characteristics

Aerobic granular sludge, result of self-aggregation of microorganisms, is expected to have the ability to improve the performance of aerobic reactor. In this dissertation, experimental studies of the cultivation process of aerobic granular sludge by seeding anaerobic granular sludge in SBR, the characteristics and application of aerobic granular sludge were investigated. Following results have been obtained:Aerobic granular sludge, with regular shape and satisfactory biodegradation ability, was successfully obtained through the control of operation parameters during four weeks cultivation in SBR by seeding anaerobic granular sludge. The color of the granular sludge, originally black, changed to yellow from the surface to the center gradually. Both of granular and floccular sludge existed in the reactor at the end of the process, but granular sludge dominated in amount, with a concentration of above 5g/L. Result of different sedimentation rates, there were layered sedimentation during sedimentation period.Great difference was found between the aerobic granular sludge and anaerobic one in activated component ratio, water percentage, precipitation velocity and inner configuration. For the aerobic granular sludge, filamentous and bacillius bacteria were the dominant microorganisms while for anaerobic granular was spheral bacteria. Measurements of calcium concentration and observations of the aerobic granule through SEM revealed that the granules experienced a calcium enrichment process, finally leading to 80% calcium accumulation in the granules, and mainly in the center of the granules. Calcium and extra cellular polymers were...