Abstract
In this study, the authors set up a contact bed in the upper part of UASB (Upflow Anaerobic Sludge Blanket), named UAHB (Upflow Anaerobic Hybrid Blanket). Experimental results indicated that: (1) The contact bed not only promoted the granulation during the period of start-up, but also improved the organic matter removal. (2) When effluent is not recycled acidogenic bacteria exist mainly in the lower part and methanogenic bacteria mainly in the upper part. This reactor developed is a new kind of UAHB reactor which possesses the features of two-phase anaerobic digestion. The mechanisms of granulation in UAHB process were also discussed.
