An overview of fenton oxidation process in water and wastewater treatment

Abstract

Advanced oxidation processes (AOPs) belong to chemical oxidation process which produce and utilise hydroxyl radicals (HO • ) as their key oxidant. These processes are among the relatively recent technologies being developed to solve the environmental problems related to the generation of nonbiodegradable and toxic aqueous wastes. Although the idea of AOPs has been in existence since the mid 20 th century, active research efforts in this field has only taken place in the last 30 years (Aieta et al., 1988; Strukul, 1992; Andreozzi et al. 1999). As shown in Table 1, HO • is the second most reactive common oxidising agent known to mankind after fluorine. The typical rate constants for reaction between HO • and organic or inorganic materials are in the order of 10 6 to 10 9 M -1 s -1 (Farataziz and Ross, 1977). These rates, as shown in Table 2, are about 10 9 times higher than its closest competitor, ozone (O3) (Andreozzi et al., 1999). A combination of hydrogen peroxide (H2O2) and ferrous (Fe 2+ ), known as Fenton’s Reagent (FR) is of the AOPs. Discovered by H. J. H. Fenton in 1894, FR can be considered as the oldest AOPs. As compared to other AOPs, FR can be considered as the simplest technique in generating the HO • .