Selection and evaluation of biofilm carrier in anaerobic digestion treatment of cattle manure

Selection and evaluation of biofilm carrier represent the two significant ways for improving the anaerobic digesters. This study investigated the performances of the AD (anaerobic digestion) reactors using three types of fibrous biofilm carriers, including the ACF (activated carbon fiber), the PVAF (polyvinyl alcohol fiber) and the GF (glass fiber). The biogas and methane production, pH, COD (chemical oxygen demand), TS (total solids), VS (volatile solids), residual coenzyme F₄₂₀ as well as the residual amount of methanogen were measured periodically during the experimental run. Also, the SEM (scanning electron microscopy) was used to identify the microbial consortium and their attachments onto the surface of ACF carrier. The ACF carrier performed better than the other two types of carriers in achieving higher amount of biogas and methane production and pollutants' removal. The experimental results also demonstrated that the ACF carrier could make the reactor keep higher biogas and methane productions than the control blank reactor during the long run.