UASB Process utilizes the granulated sludge of good settleability resulting in concentration of active biomass in the reactor. However, sludge granulation is a rather slow process so as to make its applications difficult. Some inert materials could solve this problem by accelerating the granulation process.
In this study, GAC (granular activated carbon) effects on granulation and biogas production were investigated. Operation results of UASB reactors fed on synthetic media with glucose as a carbon source having 2.5 and 6.0g COD/L were discussed. When loading rate in one reactor with GAC increased up to 12 Kg COD/m .d, average COD removed, biogas production, and average methane were 75%, 6.0 L/L.d, and 64% respectively. In the other reactor with GAC, they changed to 85%, 6.5 L/L.d, and 67% respectively. Specific methanogenic activity was maximal 1.05Kg CH4-COD/m3.d in the GAC reactor, 0.83 Kg CH4-COD/m3.d in the control.