A technique using a membrane flow-cell to determine average mass transfer coefficients and tortuosity factors in biofilms

Average mass transfer coefficients of an inert compound (LiCl) within denitrifying biofilms were monitored during biofilm growth in a membrane flow cell under different flow conditions, until the biofilm reached (pseudo-) steady state. Average effective diffusivities were found to increase with the decrease in tortuosity factors of the biofilm matrix. The lowest tortuosity factor corresponded to the biofilm formed under the highest liquid velocity