Fenton-like initiation of a toluene transformation mechanism

In Fenton-driven oxidation treatment systems, reaction intermediates derived from parent compounds can play a significant role in the overall treatment process. Fenton-like reactions in the presence of toluene or benzene, involved a transformation mechanism that was highly efficient relative to the conventional Fenton-driven mechanism. A delay in hydrogen peroxide (H2O2) reaction occurred until the complete or near-complete transformation of toluene or benzene and involved the simultaneous reaction of dissolved oxygen. This highly efficient transformation mechanism is initiated by Fenton-like reactions, and therefore dependent on conventional Fenton-like parameters. Results indicated that several potential parameters and mechanisms did not play a significant role in the transformation mechanism including electron shuttles, Fe chelates, high valent oxo-iron complexes, anionic interferences in H2O2 reaction, and H2O2 formation. The Fenton-like initiation, formation, and propagation of a reaction intermediate species capable of transforming toluene, while simultaneously inhibiting H2O2 reaction is the most viable mechanism.

► Oxidative treatment of specific aromatic compounds involves novel transformation mechanism. ► The mechanism is initiated by Fenton-like reactions and dependent on conventional parameters. ► Sustained H2O2 reaction is inhibited until complete transformation of toluene. ► High oxidation efficiency (>100%) indicated Fenton-like reaction is not responsible. ► Formation/propagation of an aromatic-derived radical intermediate is probable mechanism.