Evaluation of Aerobic Granular Activated Sludge Process for the Nutrient Removal in a Continuous and a Batch Modes

초록

When suspended microorganisms in an activated sludge process are gently mixed, it could achieve granular activated sludge due to the extra polymeric substances(EPSs), which function as an agent of interparticle bridging for self-granulation process. The characteristics of aerobic granulation, its treatment performance, the effect of electron acceptors on the granulation are studied through batch- and continuous-type experiments. The experimental results indicated that the granulation is proceeded in three steps; the advent of filamentous bacteria, recombination, and regranulation. The filamentous bacteria played a catalytic role in the granulation process. In the comparison between suspended-activated sludge and the granular sludge, the granular sludge showed three times higher specific respiration rate than suspended activated sludge. Specific denitrification rate was also high in the granular sludge. The granulation process was most rapid when sulfate was added, thus it was likely that the sulfate ion had positive effect on the granulation. (poster presentation)