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)Cl<sub>3</sub>∙3H<sub>2</sub>O] and [Fe(terpy)Cl<sub>2</sub>]) 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/H<sub>2</sub>O<sub>2</sub>) effectively oxidize phenol at neutral pH. Besides, the factorial designing study is performed by considering three independent variables: (i) [Fe] (<em>A</em>), (ii) pH (<em>B</em>), and (iii) [H<sub>2</sub>O<sub>2</sub>] (<em>C</em>). For the Fenton reaction, the normal probability plot reveals that two factors, such as concentration of Fe<sup>2+</sup> and interaction{[H<sub>2</sub>O<sub>2</sub>]∙pH} have considerable influence on the phenol oxidation; in the normal probability plot of the complexes, factors C (concentration of H<sub>2</sub>O<sub>2</sub>) and AC {[Fe]∙[H<sub>2</sub>O<sub>2</sub>]} have an effect on the oxidation of the phenol by [Fe(terpy)Cl<sub>2</sub>]/H<sub>2</sub>O<sub>2</sub>, while for [Fe(TBMA)Cl<sub>3</sub>∙3H<sub>2</sub>O], factors B and AC significantly influence the degradation. Of both iron complexes, [Fe(TBMA)Cl<sub>3</sub>∙3H<sub>2</sub>O]/H<sub>2</sub>O<sub>2</sub> is an excellent oxidant, showing a good response at pH 7.0.