Treatment and Characterization of Chromium from Tannery Industry Effluents by Electrocoagulation Process Using Aluminum Electrode

Abstract

The performance of electrocoagulation using Aluminum electrodes for the treatment of chromium
from tannery effluent using fixed bed electrochemical batch reactor was studied. The efficiency
evaluation of electrocoagulation in removing chromium metal from Amhara region real industrial
tannery wastewater, collected from Bahirdar, Debrebrihan, and Haik was investigated. The treated
and untreated samples were determined by inductively coupled plasma-optical emission
spectrometry. The effect of operational parameters such as applied current density, initial pH,
initial metal concentration, temperature and Voltage was studied. The results indicated that Cr
removed in all experiments with high removal percentages. The optimal results were obtained,
regarding both cost and electrocoagulation efficiency with initial pH 3, concentration = 40 mg/L,
electrolysis time = 30 min, current density = 40 mA/cm2
and temperature of 25oC favored
chromium metal removal. The maximum removal percentages of chromium were 84.42% for
Haik, 92.64% for Bahirdar and 94.90% for Debrebrihan. Hence, after the electrocoagulation
process, chromium may be used again as a tanning agent in leather processing.