Heterogeneous Fenton Oxidation Catalysed by Rebar Flakes Waste for Removal of Methyl Orange in Water

Abstract

Construction and demolition waste from the whole planet is around 3 billion tons per year. Steel-based waste is one of the most significant which was estimated at about 10% of total construction waste. In this study, a catalyst derived from rebar flakes waste (RFW) was investigated for heterogeneous Fenton oxidation of methyl orange (MO) in water. The catalyst was characterized using Particle Size Analyzer, SEM-EDX analysis, XRD analysis, and AAS analysis. RFW catalyst contains 60.19% (in wt) of iron, in form of magnetite (Fe3O4), hematite (Fe2O3), and wustite (FeO). RFW catalyse Fenton oxidation of MO was investigated under various experimental conditions as follows: catalyst dosage (0.5-1.5 g/L), oxidant dosage (3.3-26.4 mM), pollutant concentration (10-200 ppm), pH (2-4), and temperature (30-60◦C). Decolourisation of MO was improved by high catalyst dosage, acidic solution, and high temperature. Decolourisation up to 97% in 3 hours was observed at 0.75 g/L RFW catalyst, 6.6 mM H2O2, solution pH at 3, and temperature at 60◦C. Evaluation of iron leaching suggests that the Fenton oxidation of MO was due to the concomitant reaction of the heterogeneous and homogeneous pathway.

Keywords

• fenton catalyst
• construction waste
• advanced oxidation processes
• dye removal
• operating parameters