Decolourization of anionic dye by activated carbon-supported nano-zero valent iron (NZVI)

Abstract

This study investigates the capability of activated carbon-supported nano-zero valent iron (AC-nZVI) to remediate the anionic dye (Acid Orange II). The supported nanoparticles (AC-nZVI) were synthesized by using chemical reduction method of Ferric Chloride Tetrahydrate and Sodium Borohydride, NaBH4 solutions. The absorbents of nZVI and AC-nZVI were characterized by using Brunnaer–Emmett–Teller (BET) surface area, Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy with Auger Electron Spectroscopy (XPS-AES). Batch Tests were also conducted to delineate the effectiveness of adsorbent materials in removing Acid Orange II. Batch tests involved of five effects including dose, initial concentration, pH, kinetic and temperature. In initial concentration effect, AC-nZVI exhibits larger adsorption capacity (4.41 mg/g) compared to activated carbon (1.82 mg/g) due to the dispersion of nZVI particles on activated carbon particles, consequently providing more sites for adsorption. The results also revealed that the supported nZVI can be an effective absorbent to remove anionic dye wastewater.