COD/N ratios of up to 6 and 8 but the amount did not increasewhen
the COD/N ratio was up to 10. With respect to the residual COD in
the effluent, values lower than 30 mg/L with COD/N ratios of 2, 4
and 6, and increased concentrations with COD/N ratios of 8 and 10
were obtained in the treated effluent after 4.5 h of reaction.
Therefore, the optimal COD/N ratio (where both the COD and ni-
trogen concentrations reached minimumvalues in the effluent) for
FLFWwas 6. The following discussion about FLFWwas based on the
COD/N ratio of 6.