Hitherto, more efforts on advanced treatment of biologically pretreated
CGW are still necessary.
A treatment method proven to be effective in treatment of varied
refractory-containing organic wastewaters is Fenton oxidative
process (Oller et al., 2011). However, the classic homogeneous Fenton
reaction which is catalyzed by soluble Fe2+ has some critical
limitations such as the rapid precipitation of Fe(OH)3, which generates
significant amounts of sludge. Moreover, the ferric hydroxide
sludge produced is the source for the decomposition of hydrogen
peroxide (Hua et al., 2014). To avoid this problem, the heterogeneous
Fenton oxidation (HFO) process has been employed, where
the active phase is supported by porous matrices. Among the most
promising supports for this application are activated carbons (ACs),
because of their high surface areas, high stability and easy control
of their texture and surface chemistry (Duan et al., 2014).
Meanwhile, an increasing amount of sewage sludge generated by
biological wastewater treatment plant has become an issue of
particular concern. It is a better option to reuse residual sewage