Removal of Chromium from Wastewater by Wet Chemical Ferrite Process

Abstract

The present research work focuses on the removal of Chromium (III) from industrial waste water using the technique of wet chemical ferrite process resulting in ferrite in the nanoparticle range. Using synthetic waste water containing Chromium (VI) this study investigated the efficient removal of Chromium (VI) by precipitating the metal as Chromium ferrite, the supernatant obtained being analyzed using Atomic Absorption Spectroscopy (AAS). Efficiency of the removal has been observed by varying the Fe2+/Cr3+ weight ratio from 10 to 20, the reaction pH from 9 to 12 and reaction time from 1 to 3 hours. The most efficient removal of Chromium (<0.5ppm) was achieved for a weight ratio of 18 at pH 12 and the reaction time of 1 hr. Decreasing the pH influenced the sludge particle morphology and magnetization, with decrease in percent removal of Chromium. The produced sludge was characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). XRD results confirmed the pure spinel phase formation of Chromium ferrite. SEM images confirmed the homogenous particles with size ranging from 22 nm to 116 nm with decrease in pH from 12 to 9. M-H curves from VSM showed strong magnetic properties for Chromium ferrite sludge obtained at pH 12 and Fe2+/Cr3+ weight ratio 18. TCLP results confirmed the stability and non-toxic nature of the ferrite sludge.