SLUDGE CHARACTERISTICS OF A UASB/CO_2-STRIPPER SYSTEM FOR THE TREATMENT OF HIGH STRENGTH WASTEWATER

摘要

A new anaerobic reactor variation, the UASB/CO_2-stripper reactor was conceived. It consisted of a conventional UASB reactor that recirculated the biogas produced. The sludge characteristics of this system were examined when treating high strength wastewater. From the data collected, it was obvious that the UASB/CO_2-stripper system can satisfactorily operate at higher loading rates (25 g CODL~(-1)d~(-1)). A pronounced effect on the quality of the granular sludge was observed. The VSS/TSS ratio decreased sharply. A considerable decrease in the mean granule diameter was observed, while the specific gravity of the granules increased. The sludge bed porosity increased significantly leading to a considerable expansion of the sludge bed. These changes in the sludge properties led to a gradual shift of the system towards a fluidized bed process as far as its hydraulic characteristics were concerned.