Abstract:
Potentially toxic metal/metalloid contamination of water is inevitable mainly due to anthropogenic
activities and pose highly adverse health effects on humans. Therefore, development of cost effective
promising green technology is of immediate priority concern worldwide. Electrocoagulation holds
great promise for the remediation of water and wastewater contaminated by toxic metal ions and
organic pollutants. This study evaluates the electrocoagulation performance for the removal of 5 ppm
Cr(VI) in simulated water composed of 0.003 mol dm-3 Na2SO4 which imparts a conductivity of 600
s cm-1. The electrocoagulation process, in terms of pH, conductivity, dissolution rate of both anode
and cathode, current density was monitored at fixed direct current potentials in a range 1V to 5V at
initial pH of 6.5 in a batch mode reactor. In the first 10 min, pH was found to increase from 6.5 to 9.0
and remained constant until the end of the electrocoagulation process after 60 min. Higher rate of
dissolution of both anode and cathode was noticed due to electro oxidation and chemical dissolution
of the anode and cathode respectively. The removal of Cr(VI) was monitored by UV-Visible
spectroscopy at 370 nm and Inductively-Coupled Mass Spectroscopy (ICP-MS).The maximum
removal of 97% achieved after two hours of electrocoagulation. The X-ray Diffraction (XRD) and
Fourier Transform Infrared Spectroscopy (FTIR) studies performed on dried electrochemically
generated sludge in the electrocoagulation reactor revealed the presence of Al and Cr.
Keywords: Electrocoagulation; Batch-mode reactor; Pollution abatement; Cr(VI); Al electrodes
