3.4. Mineralization
Acommonmethod for characterizing Fenton process is to determine
the mineralization of leachate. Measurements of TOC removal
were carried out to evaluate the mineralization of leachate. Except
for the interaction terms X1X2 and X2X3, the other linear terms (X1,
X2 and X3), quadratic terms (X1
2, X2
2 and X3
2) and the interaction
terms (X1X3) were statistically significant (Table 3). Addition
of H2O2 and Fe2+ had positive linear effects (X2 and X3) and negative
quadratic effects (X2
2 and X3
2) (Table 2). The perturbation plot
(Fig. 5(a)), which was observed to be similar to that of overall COD
removal, also showed the mineralization was largely controlled by
the initial pH, followed by the level of Fe2+ and H2O2 dosages. The
results enabled identification of a point of maximum mineralization
as a function of these two factors (X2 and X3) involved in a
determined initial pH.