A novel method for the remediation of o‐ and p‐aminophenol from industrial wastewater by hexacyanoferrate (III) ions using Ir‐complex catalyst

Abstract

In this manuscript o‐ and p‐aminophenols model environmental pollutants are being remedied by catalytic oxidation process. A kinetic‐spectrophotometric technique was used to study the remediation of o‐ and p‐aminophenol by hexacyanoferrate (III) ions as an oxidant and synthesized Ir‐DTPy complex as a catalyst in aqueous alkaline medium. The optimum pH for these experiments was 9.0 and 11.0 for o‐ and p‐aminophenol respectively at the constant temperature 25°C. It has been studied how variations in the concentration of the catalyst (Ir‐DTPy), the hexacyanoferrate (III) ions, and substrate affect the rate of the reaction. At four different temperatures, ranging from 25 to 40°C, the change in reaction rate has been analyzed with thermodynamic variables like free energy of activation, enthalpy, frequency factor, and activation energy. FTIR, UV‐Vis, and ESI‐MS spectroscopic analytical methods have been used to identify the oxidized products. 2‐aminophenoxazin‐3‐one and NN'‐bis‐(p‐hydroxyphenyl)‐2‐hydroxy‐5‐amino‐1, 4‐benzoquinone di‐imine are the main products of oxidation of o‐and p‐aminophenol, respectively. Therefore, this technique for removing o‐ and p‐aminophenol from contaminated water resources is very effective and environmentally safe.