3. Results and discussion
3.1. Effect of Fe2+ dosage
The OH radicals are trapped by Fe2+ ions in excess as shown
in the reaction (4) (Bouasla et al., 2010). To see the effect of
Fe2+ dosage in the Fenton process and to determine the most
appropriate concentration of Fe2+, a series of experiments
were conducted at different concentrations of Fe2+ from 0
to 5 mg L1. H2O2 concentration was 50 mg L1 at an initial
pH of 3.0. As shown in Fig. 2, Fe2+ concentration was
0 mg L1 and only 31.1% color and 22.4% COD were removed
when H2O2 alone was used. The addition of Fe2+
would increase color and COD removal in the presence of
H2O2. It is because Fe2+ ions react with hydrogen peroxide