Using Eq. (6), the SS fraction was calculated as 58.35%, and Xs
could then be evaluated as 41.65%, showing that the readily
biodegradable organics in FLFW was very high. However, the TOA
directly measured from FLFW took only 24.6% of SCOD. This indi-
cated that in the FLFW not only organic acids but also a large
portion of other organics would also be easily used by denitrifying
bacteria. The Ss fraction of domestic wastewater is usually 10e20%
of TCOD (Henze et al., 1994). The much higher Ss fraction in FLFW
explains that it is a high quality carbon source for enhancing
denitrification