Influence of degassing process, blank's headspace and inoculum type on the biodegradability assays

Anaerobic digestion is a multi-step process for conversion of organics wastes to methane (CH4), for energy and biofuels production. The range of application is expanding, as well as the covered studies. The variety of equipment and methods used for access the biomethane potential in batch assays makes their comparison very difficult. This work aims to evaluate the influence of some parameters, like the type of inoculum (suspended sludge, granular sludge and manure), the pre-consumption of the residual substrate and the volume of the headspace in the blank assay (no addition of substrate), in determination of biochemical methane potential (BMP) and anaerobic biodegradability (B0) of wastes. The blank assays used to discount the CH4 produced are crucial to a correct determination of BMP and B0. Moreover, higher amounts of CH4 produced in smaller volumes of headspaces could minimize errors propagation. The degassing process appears to be unnecessary for the suspended and granular sludge