Chlorine dioxide catalytic oxidation by zero valent iron for the degradation of PNP in aqueous solution

Abstract

In order to evaluate the degradation of p-nitrophenol (PNP) in aqueous solution by chlorine dioxide oxidation process catalyzed by Fe0 micro-particles, the effects of Fe0 dosage (0-5.0 g/L), ClO2 dosage (0-2.0 g/L), initial pH (3.0-13.0) and air flow rate (0-5.0 mL/min) on chemical oxygen demand (COD) removal of PNP in aqueous solution were investigated comprehensively. In particular, the maximum COD removal was obtained under the optimal conditions (i.e., Fe0 dosage of 4.0 g/L, ClO2 dosage of 1.2 g/L, initial pH of 5.0, stirring speed of 300 rpm and reaction time of 30 min). Meanwhile, the two control experiments (i.e., Fe0 alone and ClO2 alone systems) were carried out to confirm the performance of chlorine dioxide oxidation process catalyzed by Fe0 micro-particles. In a word, the study provided an effective and promising catalytic oxidation technology for toxic and refractory pollutants.