Effects of Added Powdered and Granular Activated Carbons on Start-Up Performance of UASB Reactors

The effects of powdered activated carbon (PAC) and granular activated carbon (GAC) on the start-up of upflow anaerobic sludge blanket (UASB) reactors were investigated in this study. Three reactors treating a synthetic wastewater were operated concurrently for 129 days. Sludge granulation was achieved in the control reactor within approximately 95 days, while dosing PAC and GAC reduced granulation time by approximately 30 and 35 days, respectively. The PAC- and GAC-added reactors had higher biomass concentrations. At the end of the 129-day experiment, the PAC- and GAC-added reactors had biomass concentrations of 10.1 and 10.3 g-MLVSS l−1, respectively, while the control reactor had a biomass concentration of 9.6 g-MLVSS l−1. Granules became noticeable earlier in the PAC- and GAC-added reactors (on Days 40 and 36, respectively). The control reactor was the last one in which granules became visible (on Day 63).