Methods Influence in Surface Area Result from Polyurethane Used as Support Media

We evaluated if different measurement methods influence the surface area results from a polyurethane sponge used as support media in biofilm reactors. The surface area values are normally used to characterize and present advantages from supported medias. However, the methodology to determine it is barely discussed. We compared two specific surface area methodologies: Brunauer-Emmett-Teller (BET) and analysis of images obtained by a scanning electron microscope (SEM). Specific surface area by BET was 93769.1 m² m^-3 (average); for SEM methodology, 10586.6 m² m^-3. The BET value was higher than expected in reality, and the SEM method result was more suitable and used as data input in a mathematical modeling.