An ef fi cient heterogeneous Fenton catalyst based on modified iron rich soil for discoloration of Tartrazine simulated wastewater

Abstract

An iron rich soil resource containing 67% Fe2O3 that is inactive towards the discoloration of tartrazine (TA) at neutral pH was used to prepare composites with charcoal obtained from aniline. The Composites were obtained by heating this soil, aniline and sulphuric acid under air at 400°C and 600°C and the products (or catalyst) were denoted as Cal400 and Cal600, respectively. Cal400 and Cal600 were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X‐ray Diffraction, X‐ray Fluorescence and Nitrogen adsorption Brunauer‐Emmet‐Teller (N2‐BET). Their catalytic activities were monitored by discoloration of tartrazine yellow dye and were performed by varying catalyst load (0.065, 0.125, 0.250, 0.375 and 0.500 g/L), H2O2 concentration (8, 16, 24 mol/L) and pH (5, 7, 8).The influence of NaCl, Na2CO3 and NaHCO3 (1g/L) on the catalytic performance and the influence of initial pH on the iron leaching was also addressed. 94% of tartrazine was discolored after 120 min of reaction with catalyst dose of 0.065 g/L; initial tartrazine concentration of 55 mg/L; H2O2 concentration of 8mM and initial pH = 7. Leaching test indicated that the leached iron from the catalyst was less than 5 mg/L. Although all ions under study inhibited discoloration significantly, the inhibition efficiency of Cl‐ is less than that of the others ions.

Keywords

• Iron rich soil
• Fenton‐like process
• Dye discoloration
• Wastewater treatment