conditions
was investigated (Papic et al., 2009). However, removal
efficiency would decrease when H2O2 addition was higher than
125 mg L1. According to the reaction (1), the concentration
of OH is expected to increase with increasing H2O2 dosage,
leading to increased oxidation rates of organic compounds.
However, as mentioned above, excess H2O2 interferes with
the measurement of COD. The residual H2O2 in the Fenton
process can consume K2Cr2O7, leading to the increase of inorganic
COD (Kang et al., 2002). Additionally above the limiting
point, OH efficiently reacts with H2O2 and produces HO2.
HO2 radicals are less reactive than OH, increasing HO2 results
in negligible contribution (Schrank et al., 2007).