Use of Ligand-based Iron Complexes for Phenol Degradation by Fenton Modified Process

Abstract

The efficiency of phenol degradation by the iron complexes ([Fe(TBMA)Cl₃∙3H₂O] and [Fe(terpy)Cl₂]) is compared with that of the Fenton reaction. The results show that although the Fenton reaction efficiently oxidizes phenol at low pH’s, the Fenton modified reagents (iron complexes/H₂O₂) effectively oxidize phenol at neutral pH. Besides, the factorial designing study is performed by considering three independent variables: (i) [Fe] (A), (ii) pH (B), and (iii) [H₂O₂] (C). For the Fenton reaction, the normal probability plot reveals that two factors, such as concentration of Fe²⁺ and interaction{[H₂O₂]∙pH} have considerable influence on the phenol oxidation; in the normal probability plot of the complexes, factors C (concentration of H₂O₂) and AC {[Fe]∙[H₂O₂]} have an effect on the oxidation of the phenol by [Fe(terpy)Cl₂]/H₂O₂, while for [Fe(TBMA)Cl₃∙3H₂O], factors B and AC significantly influence the degradation. Of both iron complexes, [Fe(TBMA)Cl₃∙3H₂O]/H₂O₂ is an excellent oxidant, showing a good response at pH 7.0.